Gender Differences in Cardiac Organ Damage in Arterial Hypertension: Assessing the Role of Drug Nonadherence

INTRODUCTION

Cardiac organ damage like left ventricular (LV) hypertrophy and left atrial (LA) enlargement is more prevalent in women than men with hypertension, but the mechanisms underlying this gender difference remain unclear.

METHODS

We tested the association of drug nonadherence with the presence of LV hypertrophy and LA enlargement by echocardiography in 186 women and 337 men with uncontrolled hypertension defined as daytime systolic blood pressure (BP) ≥ 135mmHg despite the prescription of at least two antihypertensive drugs. Drug adherence was assessed by measurements of serum drug concentrations interpreted by an experienced pharmacologist. Aldosterone-renin-ratio (ARR) was measured on actual medication.

RESULTS

Women had a higher prevalence of LV hypertrophy (46% vs. 33%) and LA enlargement (79% vs 65%, both p < 0.05) than men, while drug nonadherence (8% vs. 9%, p > 0.514) did not differ. Women were older and had lower serum renin concentration and higher ARR than men, while 24-h systolic BP (141 ± 9 mmHg vs. 142 ± 9 mmHg), and the prevalences of obesity (43% vs. 50%) did not differ (all p > 0.10). In multivariable analyses, female gender was independently associated with a two-fold increased risk of LV hypertrophy (OR 2.01[95% CI 1.30-3.10], p = 0.002) and LA enlargement (OR 1.90 [95% CI 1.17-3.10], p = 0.010), while no association with drug nonadherence was found. Higher ARR was independently associated with LV hypertrophy in men only (OR 2.12 [95% CI 1.12-4.00] p = 0.02).

CONCLUSIONS

Among patients with uncontrolled hypertension, the higher prevalence of LV hypertrophy and LA enlargement in women was not explained by differences in drug nonadherence.

REGISTRATION

URL:  https://www.

CLINICALTRIALS

gov ; Unique identifier: NCT03209154.

Ziziphus Oxyphylla hydro-methanolic extract ameliorates hypertension in L-NAME induced hypertensive rats through NO/cGMP pathway and suppression of oxidative stress related inflammatory biomarkers

ETHNOPHARMACOLOGICAL RELEVANCE

Ziziphus Oxyphylla belongs to family Ziziphus and has been used traditionally in hypertension. It is enriched with quercetin and kaempferol derivatives, catechin and cyclopeptide alkaloids.

AIM

The current research evaluates the antihypertensive potential of aqueous methanolic extract of Z. oxyphylla (AMEZO) in NG-nitro-L-arginine methyl ester (LNAME) induced hypertension in rats.

MATERIAL AND METHODOLOGY

Phytochemical analysis of AMEZO was carried out using high performance liquid chromatography (HPLC) and electrospray ionization mass spectrometry (ESI-MS/MS). Antihypertensive activities of AMEZO (200 and 400 mg/kg) and Kaempferol were assessed in L-NAME (185 μmol/kg, intraperitoneal) injected hypertensive rats. In normotensive rats, blood pressure was assessed using Power Lab data system. Serum and tissue samples were preserved for estimation of nitric oxide (NO), Cyclic guanosine monophosphate (cGMP), interleukin-6 (IL-6), tumor necrosis factor (TNF- α) and oxidative stress markers respectively. mRNA levels of eNOS, ACE, COX-2 and NF-kB genes were assessed through qPCR.

RESULTS

The HPLC and ESI-MS/MS identified kaempferol, quercetin, catechin, ceanothic acid, zizybernalic acid and oxyphylline F. Chronic administration of AMEZO and kaempferol in L-NAME induced hypertensive rats significantly (p < 0.001) reduced systolic, diastolic and mean blood pressure. AMEZO and kaempferol caused meaningfully improved (p < 0.001) serum NO and cGMP levels. AMEZO administration also noticeably decrease the elevated IL-6 and TNF- α concentration in hypertensive animals. Administration of AMEZO and kaempferol also improved oxidative stress markers (MDA, CAT, SOD, GSH). The antihypertensive activity of AMEZO also resulted in upregulation of eNOS and downregulation of ACE.

CONCLUSION

These data depict that AMEZO and kaempferol showed antihypertensive activity in LNAME induced hypertensive rats possibly mediated through improvement in NO and cGMP levels, modulation of mRNA expression of eNOS, ACE, COX-2 and NF-kB and suppression of oxidative stress related inflammatory markers, proposing a defensive role in cardiovascular diseases.

Considerations for Inotrope and Vasopressor Use in Critically Ill Patients With Pulmonary Arterial Hypertension

ABSTRACT

Pulmonary arterial hypertension (PAH) is a rare and progressive cardiopulmonary disease, characterized by pulmonary vasculopathy. The disease can lead to increase pulmonary arterial pressures and eventual right ventricle failure due to elevated afterload. The prevalence of PAH in patients admitted to the intensive care unit (ICU) is unknown, and pulmonary hypertension (PH) in the ICU is more commonly the result of left heart disease or hypoxic lung injury (PH due to left heart disease and PH due to lung diseases and/or hypoxia, respectively), as opposed to PAH. Management of patients with PAH in the ICU is complex as it requires a careful balance to maintain perfusion while optimizing right-sided heart function. A comprehensive understanding of the underlying physiology and underlying hemodynamics is crucial for the management of this population. In this review, we summarized the evidence for use of vasopressors and inotropes in the management of PH and extrapolated the data to patients with PAH. We strongly believe that the understanding of the hemodynamic consequences of inotropes and vasopressors, especially from data in the PH population, can lead to better management of this complex patient population.

Indole-3-propionic acid, a tryptophan-derived bacterial metabolite, increases blood pressure via cardiac and vascular mechanisms in rats

Recent evidence suggests that gut bacteria-derived metabolites interact with the cardiovascular system and alter blood pressure (BP) in mammals. Here, we evaluated the effect of indole-3-propionic acid (IPA), a gut bacteria-derived metabolite of tryptophan, on the circulatory system. Arterial BP, electrocardiographic, and echocardiographic (ECHO) parameters were recorded in male, anesthetized, 12-wk-old Wistar-Kyoto rats at baseline and after intravenous administration of either IPA or vehicle. In additional experiments, rats were pretreated with prazosin or pentolinium to evaluate the involvement of the autonomic nervous system in cardiovascular responses to IPA. IPA's concentrations were measured using ultra-high performance liquid chromatography tandem mass spectrometry. The reactivity of endothelium-intact and -denuded mesenteric resistance arteries was tested. Cells' viability and lactate dehydrogenase (LDH) cytotoxicity assays were performed on cultured cardiomyocytes. IPA increased BP with a concomitant bradycardic response but no significant change in QTc interval. The pretreatment with prazosin and pentolinium reduced the hypertensive response. ECHO showed increased contractility of the heart after the administration of IPA. Ex vivo, IPA constricted predilated and endothelium-denuded mesenteric resistance arteries and increased metabolic activity of cardiomyocytes. IPA increases BP via cardiac and vascular mechanisms in rats. Furthermore, IPA increases cardiac contractility and metabolic activity of cardiomyocytes. Our study suggests that IPA may act as a mediator between gut microbiota and the circulatory system.

Opposing Responses of the Calcium Channel Blocker Nicardipine to Vascular Stiffness in the Elastic and Muscular Arteries in Rabbits

AIM

The cardio-ankle vascular index (CAVI) consists of intrinsic and functional arterial stiffness mainly regulated by vasoactive compounds. A new stiffness index of the aorta (aBeta) and iliac-femoral arteries (ifBeta) was determined by applying the CAVI theory to the whole aorta and iliac-femoral arteries. We investigated the changes in aBeta and ifBeta in response to decreased blood pressure (BP) induced by the Ca2＋ channel blocker nicardipine to elucidate the involvement of Ca2＋ in aBeta and ifBeta.

METHODS

Pressure waves at the origin of the aorta (oA), distal end of the abdominal aorta (dA), and left femoral artery (fA) as well as flow waves at the oA were simultaneously recorded before and after the infusion of nicardipine (50 µg/kg/min) for 2 min in 12 male rabbits under pentobarbital anesthesia. Beta was calculated using the following formula: Beta=2ρ / PP×ln (SBP / DBP)×PWV2, where ρ, SBP, DBP, and PP denote blood density and systolic, diastolic, and pulse pressures, respectively. aBeta, ifBeta, and aortic-iliac-femoral Beta (aifBeta) were calculated using aPWV, ifPWV, and aifPWV, respectively.

RESULTS

SBP, mean arterial pressure (MAP), DBP, and total peripheral vascular resistance significantly decreased during the administration of nicardipine, whereas cardiac output significantly increased. aBeta and ifBeta significantly increased and decreased, respectively, whereas aifBeta did not change despite the decrease in BP. ifBeta and aBeta positively and negatively correlated with BP, respectively, whereas aifBeta did not correlate with SBP.

CONCLUSIONS

There were contradictory arterial responses to nicardipine between the elastic and muscular arteries. Unknown vasoconstriction mechanisms that are not involved in Ca2＋ influx may function in the aorta in response to decreased BP.

Nifedipine disturbs fetal cardiac function during hypoxemia in a chronic sheep model at near term gestation

BACKGROUND

Nifedipine is a widely used drug in pregnancies complicated by maternal hypertensive disorders that can be associated with placental insufficiency and fetal hypoxemia. The evidence regarding fetal myocardial responses to nifedipine in hypoxemia is limited.

OBJECTIVE

We hypothesized that nifedipine would not impair fetal sheep cardiac function under hypoxemic environment. In particular, we investigated the effects of nifedipine on fetal ventricular functional parameters and cardiac output.

STUDY DESIGN

A total of 21 chronically instrumented fetal sheep at 122 to 134 gestational days (term, 145 days) were included in this study. Fetal cardiac function was evaluated by measuring global longitudinal strain, indices describing ventricular systolic and diastolic function, and cardiac outputs using two-dimensional speckle tracking and tissue and spectral pulsed-wave Doppler echocardiography. Fetal carotid artery blood pressure and blood gas values were invasively monitored. After baseline data collection, fetal hypoxemia was induced by maternal hyperoxygenation. After hypoxemia phase data collection, 9 fetuses received nifedipine infusion, and 12 fetuses received saline infusion. Data were collected 30 and 120 minutes after the infusion was started. After 120 minutes of data collection, maternal and fetal oxygenation were normalized, and normoxemia phase data were collected, while infusion was continued.

RESULTS

Hypoxemia decreased fetal carotid artery mean arterial pressure from 40 (8) mm Hg to 35 (8) mm Hg (P<.007), and left ventricular global longitudinal strain showed less deformation than at baseline (P=.001). Under hypoxemia, nifedipine caused a reduction in right ventricular global longitudinal strain (P<.05), a decrease in right ventricular isovolumic relaxation velocity and its deceleration (P<.01) indicating diastolic dysfunction, and a drop in right ventricular cardiac output (P<.05). Nifedipine did not alter fetal left ventricular functional parameters or cardiac output. When normoxemia was restored, fetal right ventricular functional parameters and cardiac output returned to baseline level.

CONCLUSION

In hypoxemic fetus, nifedipine impaired right ventricular function and reduced its cardiac output. The detrimental effects of nifedipine on fetal right ventricular function were abolished, when normoxemia was restored. Our findings suggest that in a hypoxemic environment nifedipine triggers detrimental effects on fetal right ventricular function.

Albumin covering maintains endothelial function upon magnetic iron oxide nanoparticles intravenous injection in rats

Magnetic iron oxide nanoparticles (IONP) present the promising instrument for broad-spectrum of clinical applications, for example, targeted drug delivery. Reactivity of nanoparticles depends on their surface area and material. In the blood plasma IONP are getting covered with an albumin crown, so it was decided to test this shell for biocompatibility. Male Wistar rats were anesthetized and underwent laparotomy. Abdominal aorta was connected to external hemodynamic loop with regulated blood flow. Hind body quarter got step-like blood flow changing from 30 to 150 mmHg and back. This was followed with i.v. injection of IONP, albumin solution or albumin-covered IONP and consequent similar flow changes. Central hemodynamics-heart rate and mean arterial pressure were registered throughout the experiment and no significant changes in these parameters were observed. Hind paw microcirculation level had the same dynamic in all groups under changing blood flow conditions. At the end, venous blood was collected for endothelin-1 and NO evaluation that showed similar changes and no endothelial damage. Mesenteric arteries and femoral artery reactivity were evaluated with wire myography. Mesenteric arteries had the most relaxing function preservation after albumin-covered IONP injection. Given data reveal advantage of albumin-coated IONP so this can be used for further investigations as a vascular-safe vehicle.

Alamandine but not angiotensin-(1-7) produces cardiovascular effects at the rostral insular cortex

Experiments aimed to evaluate the tissue distribution of Mas-related G protein-coupled receptor D (MrgD) revealed the presence of immunoreactivity for the MrgD protein in the rostral insular cortex (rIC), an important area for autonomic and cardiovascular control. To investigate the relevance of this finding, we evaluated the cardiovascular effects produced by the endogenous ligand of MrgD, alamandine, in this brain region. Mean arterial pressure (MAP), heart rate (HR), and renal sympathetic nerve activity (RSNA) were recorded in urethane anesthetized rats. Unilateral microinjection of equimolar doses of alamandine (40 pmol/100 nL), angiotensin-(1-7), angiotensin II, angiotensin A, and Mas/MrgD antagonist d-Pro7-Ang-1-7 (50 pmol/100 nL), Mas antagonist A779 (100 pmol/100 nL), or vehicle (0.9% NaCl) were made in different rats (n = 4-6/group) into rIC. To verify the specificity of the region, a microinjection of alamandine was also performed into intermediate insular cortex (iIC). Microinjection of alamandine in rIC produced an increase in MAP (Δ = 15 ± 2 mmHg), HR (Δ = 36 ± 4 beats/min), and RSNA (Δ = 31 ± 4%), but was without effects at iIC. Strikingly, an equimolar dose of angiotensin-(1-7) at rIC did not produce any change in MAP, HR, and RSNA. Angiotensin II and angiotensin A produced only minor effects. Alamandine effects were not altered by A-779, a Mas antagonist, but were completely blocked by the Mas/MrgD antagonist d-Pro7-Ang-(1-7). Therefore, we have identified a brain region in which alamandine/MrgD receptor but not angiotensin-(1-7)/Mas could be involved in the modulation of cardiovascular-related neuronal activity. This observation also suggests that alamandine might possess unique effects unrelated to angiotensin-(1-7) in the brain.

Maternal Thyroid Hormone Programs Cardiovascular Functions in the Offspring

Background: Maternal thyroid hormone (TH) plays an essential role for fetal development, especially for the cardiovascular system and its central control. However, the precise consequences of altered TH action during the different periods in pregnancy remain poorly understood. Methods: To address this question, we used mice heterozygous for a mutant thyroid hormone receptor α1 (TRα1) and wild-type controls that were born to wild-type mothers treated with 3,3',5-triiodothyronine (T3) during the first or the second half of pregnancy. We then phenotyped the offspring animals as adults by in vivo measurements and postmortem tissue analyses. Results: Maternal T3 treatment in either half of the pregnancy did not affect postnatal growth development. Serum thyroxine and hypophyseal thyrotropin subunit beta or deiodinase type II expression was also not affected in any group, only TRα1 mutant males exhibited a reduction in serum T3 levels after the treatment. Likewise, hepatic deiodinase type I was not altered, but serum selenium levels were reduced by the maternal treatment in wild-type offspring of both genders. Most interestingly, a significant increase in heart weight was found in adult wild-types born to mothers that received T3 during the first or second half of pregnancy, while TRα1 mutant males were protected from this effect. Moreover, we detected a significant increase in heart rate selectively in male mice that were exposed to elevated maternal T3 in the second half of the pregnancy. Conclusion: Taken together, our findings demonstrate that maternal TH is of particular relevance during the second half of pregnancy for establishing cardiac properties, with specific effects depending on TRα1 or gender. The data advocate routinely monitoring TH levels during pregnancy to avoid adverse cardiac effects in the offspring.

Apigenin Improves Hypertension and Cardiac Hypertrophy Through Modulating NADPH Oxidase-Dependent ROS Generation and Cytokines in Hypothalamic Paraventricular Nucleus

Apigenin, identified as 4', 5, 7-trihydroxyflavone, is a natural flavonoid compound that has many interesting pharmacological activities and nutraceutical potential including anti-inflammatory and antioxidant functions. Chronic, low-grade inflammation and oxidative stress are involved in both the initiation and progression of hypertension and hypertension-induced cardiac hypertrophy. However, whether or not apigenin improves hypertension and cardiac hypertrophy through modulating NADPH oxidase-dependent reactive oxygen species (ROS) generation and inflammation in hypothalamic paraventricular nucleus (PVN) has not been reported. This study aimed to investigate the effects of apigenin on hypertension in spontaneously hypertensive rats (SHRs) and its possible central mechanism of action. SHRs and Wistar-Kyoto (WKY) rats were randomly assigned and treated with bilateral PVN infusion of apigenin or vehicle (artificial cerebrospinal fluid) via osmotic minipumps (20 μg/h) for 4 weeks. The results showed that after PVN infusion of apigenin, the mean arterial pressure (MAP), heart rate, plasma norepinephrine (NE), Beta 1 receptor in kidneys, level of phosphorylation of PKA in the ventricular tissue and cardiac hypertrophy, perivascular fibrosis, heart level of oxidative stress, PVN levels of oxidative stress, interleukin 1β (IL-1β), interleukin 6 (IL-6), iNOS, monocyte chemotactic protein 1 (MCP-1), tyrosine hydroxylase (TH), NOX2 and NOX4 were attenuated and PVN levels of interleukin 10 (IL-10), superoxide dismutase 1 (Cu/Zn-SOD) and the 67-kDa isoform of glutamate decarboxylase (GAD67) were increased. These results revealed that apigenin improves hypertension and cardiac hypertrophy in SHRs which are associated with the down-regulation of NADPH oxidase-dependent ROS generation and inflammation in the PVN.

Sex differences in angiotensin II-induced hypertension and kidney injury: role of AT1a receptors in the proximal tubule of the kidney

In the present study, we tested the hypothesis that there are significant sex differences in angiotensin II (Ang II)-induced hypertension and kidney injury using male and female wildtype (WT) and proximal tubule-specific AT1a receptor knockout mice (PT-Agtr1a-/-). Twelve groups (n=8-12 per group) of adult male and female WT and PT-Agtr1a-/- mice were infused with a pressor dose of Ang II via osmotic minipump for 2 weeks (1.5 mg/kg/day, i.p.) and simultaneously treated with or without losartan (20 mg/kg/day, p.o.) to determine the respective roles of AT1a receptors in the proximal tubules versus systemic tissues. Basal systolic, diastolic, and mean arterial pressure were approximately 13 ± 3 mmHg lower (P<0.01), while basal 24-h urinary Na+, K+, and Cl- excretion were significantly higher in both male and female PT-Agtr1a-/- mice than WT controls (P<0.01) without significant sex differences between different strains. Both male and female WT and PT-Agtr1a-/- mice developed hypertension (P<0.01), and the magnitudes of the pressor responses to Ang II were similar between male and female WT and PT-Agtr1a-/- mice (n.s.). Likewise, Ang II-induced hypertension was significantly attenuated in both male and female PT-Agtr1a-/- mice (P<0.01). Furthermore, losartan attenuated the hypertensive responses to Ang II to similar extents in both male and female WT and PT-Agtr1a-/- mice. Finally, Ang II-induced kidney injury was attenuated in PT-Agtr1a-/- mice (P<0.01). In conclusion, the present study demonstrates that deletion of AT1a receptors in the proximal tubules of the kidney attenuates Ang II-induced hypertension and kidney injury without revealing significant sex differences.

Xuebijing injection in septic rats mitigates kidney injury, reduces cortical microcirculatory disorders, and suppresses activation of local inflammation

ETHNOPHARMACOLOGICAL RELEVANCE

Xuebijing injections originate from the traditional Chinese medicine (TCM) prescription XuefuZhuyu Decoction. It is composed of five Chinese herbal extracts; Carthami flos, Paeoniae radix rubra, Chuanxiong rhizoma, Salviae miltiorrhizae, and Angelicae Sinensis radix. The China Food and Drug Administration approved Xuebijing injections as a TCM preparation for the adjuvant treatment of sepsis.

AIM OF THE STUDY

This study aims to determine the effects of Xuebijing injections as an adjuvant to antibiotics for the treatment of renal microcirculatory dysfunction and renal inflammation in rats with sepsis.

MATERIALS AND METHODS

The rats received a sham operation (Sham), sham operation followed by Xuebijign injection (Sxbj), cecal ligation and puncture (CLP), or CLP followed by Xuebijing injection (Cxbj). Renal microvascular perfusion in the cortex and oxygenation were assessed at different times after sepsis induction. Renal levels of interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, and high mobility group box (HMGB)-1 were measured. Urinary TIMP-2 × IGFBP-7 and neutrophil gelatinase-associated lipocalin (NGAL) were measured as kidney biomarkers, and serum creatinine (SCr) was used to assess kidney injury. Tissue samples were stained for histologic evaluation.

RESULTS

The induction of sepsis increased local inflammation and decreased renal microvascular perfusion and oxygenation. Compared with the CLP group, the Cxbj group displayed improvements in microvascular perfusion and oxygenation (p < 0.05). The CLP group had significant increases in renal inflammatory biomarkers (IL-1β, IL-6, TNF-α, and HMGB-1; p < 0.05) and Xuebijing injection reduced the levels of these markers. The levels of urinary TIMP-2 × IGFBP-7, NAGL, and SCr were lower in the Cxbj group than in the CLP group (p < 0.05), and the CLP group had a higher Paller score than the Cxbj group (p < 0.05). However, the CLP and Cxbj groups had no significant difference in mortality.

CONCLUSIONS

This study into the early stages of sepsis in a rat model indicated that as an adjuvant therapy to antibiotics, Xuebijing injection improved renal perfusion and oxygenation, suppressed renal inflammation, and ameliorated kidney dysfunction. However, Xuebijing injection had no impact on mortality.

The role of salt-inducible kinases on the modulation of renal and intestinal Na+,K+-ATPase activity during short- and long-term high-salt intake

Type 1 salt-inducible kinases (SIK1) has been shown to act as a mediator during the cellular adaptation to variations in intracellular sodium in a variety of cell types. Type 2 SIK (SIK2) modulates various biological functions and acts as a signal transmitter in various pathways. To evaluate the role of both SIK isoforms in renal and intestinal Na+,K+-ATPase (NKA) activity, we made use of constitutive sik1-/- (SIK1-KO), sik2-/- (SIK2-KO), double sik1-/-sik2-/- (double SIK1*2-KO) knockout and wild-type (WT) mice challenged to a standard (0.3% NaCl) or chronic high-salt (HS, 8% NaCl) diet intake for 48 h or 12 weeks. Long-term HS intake in WT was accompanied by 2-fold increase in jejunal NKA activity and slight (~30% reduction) decreases in NKA in the ileum and cecum; none of these changes was accompanied by changes in the expression of α1-NKA. The ablation of SIK1 and SIK2 prevented the marked increase in jejunal NKA activity following the long-term HS intake. The ablation of SIK1 and SIK2 in mice on a long-term HS intake impacted differently in the ileum and cecum. The most interesting finding is that in SIK2-KO mice marked reductions in NKA activity were observed in the ileum and cecum when compared to WT mice, both on normal and long-term HS intake. In summary, SIK1 or SIK2 ablation on chronic high-salt intake is accompanied by modulation of NKA along the intestinal tract, which differ from those after an acute high-salt intake, and this may represent an absorptive compensatory mechanism to keep electrolyte homeostasis.

Effects of fadolmidine, an α2 -adrenoceptor agonist, as an adjuvant to spinal bupivacaine on antinociception and motor function in rats and dogs

α2 -Adrenoceptor agonists such as clonidine and dexmedetomidine are used as adjuvants to local anesthetics in regional anesthesia. Fadolmidine is an α2 -adrenoceptor agonist developed especially as a spinal analgesic. The current studies investigate the effects of intrathecally administered fadolmidine with a local anesthetic, bupivacaine, on antinociception and motor block in conscious rats and dogs. The antinociceptive effects of intrathecal fadolmidine and bupivacaine alone or in combination were tested in the rat tail-flick and the dog's skin twitch models. The durations of motor block in rats and in dogs were also assessed. In addition, the effects on sedation, mean arterial blood pressure, heart rate, respiratory rate and body temperature were evaluated in telemetrized dogs. Concentrations of fadolmidine in plasma and spinal cord were determined after intrathecal and intravenous administration in rats. Co-administration of intrathecal fadolmidine with bupivacaine increased the magnitude and duration of the antinociceptive effects and prolonged motor block without hypotension. The interaction of the antinociceptive effect was synergistic in its nature in rats. Concentration of fadolmidine in plasma was very low after intrathecal dosing. Taken together, these studies show that fadolmidine as an adjuvant to intrathecal bupivacaine provides enhanced sensory-motor block and enables a reduction of the doses of both drugs. The results indicate that co-administration of fadolmidine with intrathecal bupivacaine was able to achieve an enhanced antinociceptive effect without hypotension and could thus represent a suitable combination for spinal anesthesia.

Interferon γ neutralization reduces blood pressure, uterine artery resistance index, and placental oxidative stress in placental ischemic rats

Preeclampsia (PE) is characterized by maternal hypertension, intrauterine growth restriction, and increased cytolytic natural killer cells (cNKs), which secrete interferon γ (IFNγ). However, the precise role of IFNγ in contributing to PE pathophysiology remains unclear. Using the reduced uterine perfusion pressure (RUPP) rat model of placental ischemia, we tested the hypothesis that neutralization of IFNγ in RUPPs will decrease placental reactive oxygen species (ROS) and improve vascular function resulting in decreased MAP and improved fetal growth. On gestation day (GD) 14, the RUPP procedure was performed and on GDs 15 and 18, a subset of normal pregnant rats (NP) and RUPP rats were injected with 10 μg/kg of an anti-rat IFNγ monoclonal antibody. On GD 18, uterine artery resistance index (UARI) was measured via Doppler ultrasound and on GD 19, mean arterial pressure (MAP) was measured, animals were euthanized, and blood and tissues were collected for analysis. Increased MAP was observed in RUPP rats compared with NP and was reduced in RUPP + anti-IFNγ. Placental ROS was also increased in RUPP rats compared with NP rats and was normalized in RUPP + anti-IFNγ. Fetal and placental weights were reduced in RUPP rats, but were not improved following anti-IFNγ treatment. However, UARI was elevated in RUPP compared with NP rats and was reduced in RUPP + anti-IFNγ. In conclusion, we observed that IFNγ neutralization reduced MAP, UARI, and placental ROS in RUPP recipients. These data suggest that IFNγ is a potential mechanism by which cNKs contribute to PE pathophysiology and may represent a therapeutic target to improve maternal outcomes in PE.

Association study of fasting blood glucose and salt sensitivity of blood pressure in community population: The EpiSS study

BACKGROUND AND AIMS

To evaluate the association between fasting blood glucose (FBG) and salt sensitivity of blood pressure (SSBP).

METHODS AND RESULTS

This study is based on the baseline survey of systemic epidemiology of salt sensitivity study. Subjects were classified into salt sensitive (SS) and salt resistant groups according to blood pressure (BP) changes during the modified Sullivan's acute oral saline load and diuresis shrinkage test. Multivariate logistic and linear regression were used to evaluate associations between FBG with SS or BP changes. A total of 2051 participants were included in the analyses with 581 (28.33%) for SS. Multiple analysis showed that for every interquartile range increase in FBG, the OR (95%CI) for SS was 1.140 (1.069, 1.215), β (95%CI) for mean arterial pressure change (ΔMAP₁), systolic and diastolic BP changes during saline load were 0.421 (0.221, 0.622), 0.589 (0.263, 0.914) and 0.340 (0.149, 0.531), respectively. Compared to the lowest FBG quartile (Q₁), the OR (95%CI) for SS in Q₃ and Q₄ were 1.342 (1.014, 1.776) and 1.577 (1.194, 2.084), respectively. Compared to subjects with normal FBG, the β (95%CI) for ΔMAP₁ was 0.973 (0.055, 1.891) in subjects with impaired FBG, and was 1.449 (0.602, 2.296) in patients with diabetes mellitus. Stratified analyses showed significant and stronger associations between FBG with SSBP in youngers, females, hypertensives, non-diabetics, non-current smokers and non-current drinkers.

CONCLUSION

Our findings suggest FBG is an independent, dose-dependent associated factor for SSBP, and prevention of SS focusing on controlling FBG elevation in the early stage is important.

Comparison of intravenous magnesium sulphate and lidocaine for attenuation of cardiovascular response to laryngoscopy and endotracheal intubation in elective surgical patients at Zewditu Memorial Hospital Addis Ababa, Ethiopia

BACKGROUND

Laryngoscopy and endotracheal intubation are essential components of general anesthesia. But it is always associated with side effects called reflex cardiovascular responses. Many methods have been identified to attenuate these responses like intravenous lidocaine, deep inhalational anesthesia, vasodilators, intravenous magnesium sulphate even though therapeutic superiority remains understudied.

METHODS

An institutional-based cohort study on 112 adult patients aged between 18-60 years was applied. 37 patients in the non-exposed group (Group N), 37 in the lidocaine group (Group L), and 38 in magnesium sulphate (Group M) were included. The hemodynamic parameters like heart rate, systolic, diastolic and mean arterial blood pressure at various time points up to 7 minutes post-intubation were recorded and the effect of both drugs to reduce hemodynamic responses was compared. Parametric data were analyzed using ANOVA and nonparametric data using the Kuruska-Wallis H rank test. P-value < 0.05 considered statistically significant.

RESULTS

In all three groups, there was a statistically significant rise in heart rate and blood pressure from baseline. There was a statistically significant difference in mean heart rate throughout study minutes among the groups (p<0.001). However, there was no statistically significant difference in mean heart rate between Groups M and L at all post-intubation time intervals. In blood pressure at all three parameters there was statistically significant difference among groups at all-time points except no difference at 7th minutes in DBP. There was significantly lower blood pressure in group M compared to both groups.

CONCLUSION

In conclusion, prophylactic administration of magnesium sulphate and lidocaine was effective in attenuating hemodynamic responses to the stress effect of laryngoscopy and intubation. But based on our finding prophylaxis of magnesium sulphate is associated with a more favorable hemodynamic response.

AT II Receptor Blockade and Renal Denervation: Different Interventions with Comparable Renal Effects?

BACKGROUND

Angiotensin II (Ang II) and the renal sympathetic nervous system exert a strong influence on renal sodium and water excretion. We tested the hypothesis that already low doses of an Ang II inhibitor (candesartan) will result in similar effects on tubular sodium and water reabsorption in congestive heart failure (CHF) as seen after renal denervation (DNX).

METHODS

Measurement of arterial blood pressure, heart rate (HR), renal sympathetic nerve activity (RSNA), glomerular filtration rate (GFR), renal plasma flow (RPF), urine volume, and urinary sodium. To assess neural control of volume homeostasis, 21 days after the induction of CHF via myocardial infarction rats underwent volume expansion (0.9% NaCL; 10% body weight) to decrease RSNA. CHF rat and controls with or without DNX or pretreated with the Ang II type-1 receptor antagonist candesartan (0.5 ug i.v.) were studied.

RESULTS

CHF rats excreted only 68 + 10.2% of the volume load (10% body weight) in 90 min. CHF rats pretreated with candesartan or after DNX excreted from 92 to 103% like controls. Decreases of RSNA induced by volume expansion were impaired in CHF rats but unaffected by candesartan pointing to an intrarenal drug effect. GFR and RPF were not significantly different in controls or CHF.

CONCLUSION

The prominent function of increased RSNA - retaining salt and water - could no longer be observed after renal Ang II receptor blockade in CHF rats.

Compensatory depression of arterial pressure and reversal of ECG abnormalities by Annona muricata and Curcuma longa in hypertensive Wistar rats

OBJECTIVES

Increasing hypertension incidence in Sub-Sahara Africa and the current cost of management of the metabolic disorder has necessitated research on medicinal plants employed in African Traditional Medicine for hypertension. Thus, this study evaluated antihypertensive effect of Annona muricata leaves or Curcuma longa rhizomes in experimentally-induced hypertensive male Wistar rats (n=70) which were unilaterally nephrectomized and daily loaded with 1% salt. Cardiovascular and haematological changes, as well as urinalysis were determined.

METHODS

Rats were uninephrectomized and NaCl (1%) included in drinking water for 42 days. Extract-treated hypertensive rats were compared to normotensive, untreated hypertensive and hypertensive rats treated with lisinopril (5 mg/70 kg) or hydrochlorothiazide (12.5 mg/70 kg). A. muricata extract or C. longa extract were administered at 100, 200 or 400 mg/kg. Blood pressure (systolic, diastolic and mean arterial) and electrocardiogram was measured on day 41. Twenty-four-hour urine samples were collected from day 42. Blood samples were collected on day 43 for haematology (PCV, red cell indices, WBC and its differentials, and platelets).

RESULTS AND CONCULSIONS

A. muricata or C. longa extracts caused a decline in elevated blood pressure of hypertensive rats. Heart rate and QT segment reduction coupled with prolonged QRS duration were reversed in extract-treated rats, with significant increases in hemogram parameters indicating increased blood viscosity. Also, leukocyturia, proteinuria and ketonuria with increased urine alkalinity, urobilinogen and specific gravity which are classical indicators of poor prognostic outcomes in hypertension were reversed in extract-treated rats. In conclusion, A. muricata and C. longa have cardioprotective effect with reversal of derangements in haemogram and urinalysis associated with hypertension.

Partial Agonist Activity of Neonicotinoids on Rat Nicotinic Receptors: Consequences over Epinephrine Secretion and In Vivo Blood Pressure

Neonicotinoid insecticides are nicotine-derived molecules which exert acute neurotoxic effects over the insect central nervous system by activating nicotinic acetylcholine receptors (nAChRs). However, these receptors are also present in the mammalian central and peripheral nervous system, where the effects of neonicotinoids are faintly known. In mammals, cholinergic synapses are crucial for the control of vascular tone, blood pressure and skeletal muscle contraction. We therefore hypothesized that neonicotinoids could affect cholinergic networks in mammals and sought to highlight functional consequences of acute intoxication in rats with sub-lethal concentrations of the highly used acetamiprid (ACE) and clothianidin (CLO). In this view, we characterized their electrophysiological effects on rat α3β4 nAChRs, knowing that it is predominantly expressed in ganglia of the vegetative nervous system and the adrenal medulla, which initiates catecholamine secretion. Both molecules exhibited a weak agonist effect on α3β4 receptors. Accordingly, their influence on epinephrine secretion from rat adrenal glands was also weak at 100 μM, but it was stronger at 500 μM. Challenging ACE or CLO together with nicotine (NIC) ended up with paradoxical effects on secretion. In addition, we measured the rat arterial blood pressure (ABP) in vivo by arterial catheterization. As expected, NIC induced a significant increase in ABP. ACE and CLO did not affect the ABP in the same conditions. However, simultaneous exposure of rats to both NIC and ACE/CLO promoted an increase of ABP and induced a biphasic response. Modeling the interaction of ACE or CLO on α3β4 nAChR is consistent with a binding site located in the agonist pocket of the receptor. We present a transversal experimental approach of mammal intoxication with neonicotinoids at different scales, including in vitro, ex vivo, in vivo and in silico. It paves the way of the acute and chronic toxicity for this class of insecticides on mammalian organisms.

Pharmacokinetics and safety of TCMCB07, a melanocortin-4 antagonist peptide in dogs

The melanocortin-4 receptor (MC4R) antagonistic peptide TCMCB07 was developed for the treatment of cachexia. The objectives of this study were to examine pharmacokinetics and safety of TCMCB07 administered subcutaneously to healthy dogs. Dogs were treated with high- (2.25 mg kg-1 ) (n = 5) and low-dose TCMCB07 (0.75 mg kg-1 ) (n = 5) once daily for 28 days with a 14-day washout period between groups. Histamine levels, complete blood count, chemistry panel, blood pressure, 24-hour Holter recording, and pharmacokinetic parameters were monitored in the high-dose group. Physical examination changes were limited to weight gain and darkening of the coat color. There was no elevation of plasma histamine within 24 hours of injection but there was a significant elevation of plasma histamine across time. An approximately doubled eosinophil count and an approximately 25% increase, and then 25% decrease back to pre-treatment plasma phosphorous were also found, although both remained within the reference interval. Serial blood pressure and 24-hour Holter monitors revealed no clinically relevant changes. A difference was found in the AUC between dosing groups and a significant effect of dose, time, and interaction was noted for Vd . Low-dose TCMCB07 had a Cmax of 2.1 ug ml-1 at day 28, compared to high-dose TCMCB07 which had a Cmax 3.6 ug ml-1 at day 28. Once-daily subcutaneous administration of TCMCB07 was well-tolerated for up to 28 days in dogs when administered at doses one and three times (0.75 mg kg-1 and 2.25 mg kg-1 ) the predicted therapeutic dose and pharmacokinetic parameters are described. SIGNIFICANCE STATEMENT: Melanocortin-4 receptor (MC4R) antagonistic peptide TCMCB07 is safe at both low and high doses in dogs. Therapy was tolerated well as determined by physical examination, clinical pathology, and cardiovascular parameters; darkening of the coat was noted with treatment and resolved with discontinuation. Pharmacokinetics are described and further study in the naturally occurring canine model is warranted.

Cystamine Treatment Fails to Prevent the Development of Pulmonary Hypertension in Chronic Hypoxic Rats

INTRODUCTION

Pulmonary hypertension is characterized by vasoconstriction and remodeling of pulmonary arteries, leading to right ventricular hypertrophy and failure. We have previously found upregulation of transglutaminase 2 (TG2) in the right ventricle of chronic hypoxic rats. The hypothesis of the present study was that treatment with the transglutaminase inhibitor, cystamine, would inhibit the development of pulmonary arterial remodeling, pulmonary hypertension, and right ventricular hypertrophy.

METHODS

Effect of cystamine on transamidase activity was investigated in tissue homogenates. Wistar rats were exposed to chronic hypoxia and treated with vehicle, cystamine (40 mg/kg/day in mini-osmotic pumps), sildenafil (25 mg/kg/day), or the combination for 2 weeks.

RESULTS

Cystamine concentration-dependently inhibited TG2 transamidase activity in liver and lung homogenates. In contrast to cystamine, sildenafil reduced right ventricular systolic pressure and hypertrophy and decreased pulmonary vascular resistance and muscularization in chronic hypoxic rats. Fibrosis in the lung tissue decreased in chronic hypoxic rats treated with cystamine. TG2 expression was similar in the right ventricle and lung tissue of drug and vehicle-treated hypoxic rats.

DISCUSSION/CONCLUSIONS

Cystamine inhibited TG2 transamidase activity, but cystamine failed to prevent pulmonary hypertension, right ventricular hypertrophy, and pulmonary arterial muscularization in the chronic hypoxic rat.

Ethnopharmacological investigations of the leaves of Cecropia pachystachya Trécul (Urticaceae): A native Brazilian tree species

ETHNOPHARMACOLOGICAL RELEVANCE

Cecropia pachystachya Trécul (Urticaceae) is a medicinal plant popularly known as 'embaúba'. In Brazil, the leaves of this species are used for the treatment of various kidney and cardiovascular diseases. However, there are no detailed studies on the renal and cardiovascular activities of this species. No studies on the anatomy or the quality control of this herbal drug is available thus far.

AIM

This study was aimed to investigate the ethnopharmacological properties of the leaves of C. pachystachya.

MATERIAL AND METHODS

The leaves of C. pachystachya were analyzed by light and scanning electron microscopy for pharmacobotanical and anatomical characterization. The ethanol-soluble fraction of C. pachystachya leaf extract (ESCP) was characterized by high-performance liquid chromatograph equipped with diode array detector and mass spectrometry (HPLC-DAD-MS). The acute oral toxicity of ESCP on female Wistar rats was assessed. The acute and prolonged diuresis and antioxidant effects of ESCP (30, 100, and 300 mg/kg) were evaluated in male Wistar rats. In addition, the hypotensive effects of the ESCP as well as the vasodilatory activity in isolated and perfused mesenteric vascular beds were investigated.

RESULTS

The anatomical markers obtained in this study can help in the identification of C. pachystachya, as well as to distinguish it from the other 'embaúbas'. The metabolites found in the ESCP were phenolic compounds, mainly C- and O-glycosylated flavonoids. The ESCP did not exhibit any toxic effects at a dose of 2000 mg/kg. Significant diuretic activities were observed at the doses of 30, 100, and 300 mg/kg. In addition, a significant modulating activity of the tissue redox state was observed after prolonged treatment. On the other hand, no hypotensive or vasodilator activity was observed.

CONCLUSION

The key findings of the present study can contribute to the taxonomy, species identification and quality control of C. pachystachya. Chemical studies have shown the presence of glycosylated flavonoids, phenylpropanoid derivative and proanthocyanidins. The pharmacological studies showed significant diuretic and antioxidant effects of C. pachystachya leaf extract, indicating a possible validation of its popular medicinal use.

A study of the sequential treatment of acute heart failure with sacubitril/valsartan by recombinant human brain natriuretic peptide: A randomized controlled trial

This study aimed to investigate the effects of the basic treatment for heart failure and sequential treatment with rh-brain natriuretic peptide (rhBNP) alone or the combination of rhBNP and sacubitril/valsartan. Cardiac structure, pulmonary artery pressure, inflammation and oxidative stress in patients with acute heart failure were evaluated.Three hundred patients with acute heart failure were included. According to the random number table method, the patients were divided into 3 groups of 100 patients per group: the standard treatment group (treated with an angiotensin-converting enzyme inhibitor, β receptor blocker, and corticosteroid antagonist), rhBNP group (basic treatment combined with rhBNP) and sequential treatment group (basic treatment for heart failure combined with rhBNP followed by sacubitril/valsartan). The changes in NT-probrain natriuretic peptide (BNP) levels, cardiac troponin T (cTnT) levels, cardiac structure, pulmonary artery pressure, and the levels inflammatory factors and oxidative stress factors were compared among the 3 groups at 1, 4, 12, and 36 weeks after treatment.The sequential treatment group displayed superior outcomes than the standard treatment group and the rhBNP group in terms of left atrium diameter, left ventricular end diastolic volume, left ventricular ejection fraction, pulmonary artery pressure, NT-proBNP levels, and cTnT levels, which respond to damage to the heart structure and myocardium. This result may be related to the decreased levels of inflammatory factors and the correction of oxidative stress imbalance.Sacubitril/valsartan significantly reduce the serum levels of inflammatory factors in patients with acute heart failure while decreasing the levels of oxidizing factors and increasing the levels of antioxidant factors. These changes may be one of the explanations for the better cardiac structure and better pulmonary artery pressure observed in the sequential treatment group.

Angiotensin II receptor type 1 blockade improves hyporesponsiveness to vasopressors in septic shock

Sepsis activates the renin-angiotensin system and the production of angiotensin II, which has a key role in the regulation of blood pressure through AT1 receptors. However, excessive activation of AT1 receptor is associated with deleterious effects. We investigated the consequences of a differential blockade of AT1 receptor caused by two doses of losartan (0.25 mg/kg or 15 mg/kg, s.c), a selective AT1 receptor antagonist on sepsis outcome. These doses reduced the effect of angiotensin II in normal rats by 30% and >90% 8 h after administration, respectively, but only the higher dose maintained its inhibitory effect (~70%) 24 h after injection. Sepsis was induced by cecal ligation and puncture (CLP). Losartan was injected 2 h after CLP and parameters were evaluated 6 and 24 h after CLP. Septic rats developed hypotension and hyporesponsiveness to vasoconstrictors, an intense inflammatory process and increase in plasma markers of organ dysfunction. The lower dose of losartan improved the vasoconstrictive response to phenylephrine and angiotensin II, reduced lung myeloperoxidase and prevented leukopenia 24 h after CLP, but it did not reduce NOS-2 expression, plasma IL-6 levels or organ injury parameters of septic rats. On the other hand, the higher dose of losartan worsened the response to vasoconstrictors, potentiated the hypotension and increased further levels of creatine, urea and lactate in septic rats. Therefore, an early and partial blockade of AT1 receptor with a low dose of losartan may counteract sepsis-induced refractoriness to vasoconstrictors thus providing an opportunity to improve the outcome of this condition.

Perindopril Reduces Arterial Pressure and Does Not Inhibit Exercise-Induced Angiogenesis in Spontaneously Hypertensive Rats

ABSTRACT

Sympathetic activity, arteriolar structure, and angiogenesis are important mechanisms modulating hypertension and this study aimed to analyze the effects of perindopril treatment, associated or not with exercise training, on the mechanisms that control blood pressure (BP) in hypertensive rats. Spontaneously hypertensive rats (SHR) were allocated into 4 groups: 1/sedentary (S); 2/perindopril (P, 3.0 mg/kg/d); 3/trained (T); and 4/trained + perindopril (TP). Wistar rats were used as normotensive sedentary control group. SHR were assigned to undergo a treadmill training (T) or were kept sedentary. Heart rate, BP, sympathetic activity to the vessels (LF-SBP), and skeletal muscle and myocardial morphometric analyses were performed. BP was significantly lower after all 3 strategies, compared with S and was accompanied by lower LF-SBP (-76%, -53%, and -44%, for P, T, and TP, respectively). Arteriolar vessel wall cross-sectional area was lower after treatments (-56%, -52%, and -56%, for P, T, and TP, respectively), and only TP presented higher arteriolar lumen area. Capillary rarefaction was present in soleus muscle and myocardium in S group and both trained groups presented higher vessel density, although perindopril attenuated this increase in soleus muscle. Although myocyte diameter was not different between groups, myocardial collagen deposition area, higher in S group, was lower after 3 strategies. In conclusion, we may suggest that perindopril could be an option for the hypertensive people who practice exercise and need a specific pharmacological treatment to reach a better BP control, mainly because training-induced angiogenesis is an important response to facilitate blood flow perfusion and oxygen uptake and perindopril did not attenuate this response.

Angiotensin II type 1 receptor mediates pulmonary hypertension and right ventricular remodeling induced by inhaled nicotine

Use of electronic cigarettes is rapidly increasing among youth and young adults, but little is known regarding the long-term cardiopulmonary health impacts of these nicotine-containing devices. Our group has previously demonstrated that chronic, inhaled nicotine induces pulmonary hypertension (PH) and right ventricular (RV) remodeling in mice. These changes were associated with upregulated RV angiotensin-converting enzyme (ACE). Angiotensin II receptor blockers (ARBs) have been shown to reverse cigarette smoking-induced PH in rats. ACE inhibitor and ARB use in a large retrospective cohort of patients with PH is associated with improved survival. Here, we utilized losartan (an ARB specific for angiotensin II type 1 receptor) to further explore nicotine-induced PH. Male C57BL/6 mice received nicotine vapor for 12 h/day, and exposure was assessed using serum cotinine to achieve levels comparable to human smokers or electronic cigarette users. Mice were exposed to nicotine for 8 wk and a subset was treated with losartan via an osmotic minipump. Cardiac function was assessed using echocardiography and catheterization. Although nicotine exposure increased angiotensin II in the RV and lung, this finding was nonsignificant. Chronic, inhaled nicotine significantly increased RV systolic pressure and RV free wall thickness versus air control. These parameters were significantly lower in mice receiving both nicotine and losartan. Nicotine significantly increased RV internal diameter, with no differences seen between the nicotine and nicotine-losartan group. Neither nicotine nor losartan affected left ventricular structure or function. These findings provide the first evidence that antagonism of the angiotensin II type 1 receptor can ameliorate chronic, inhaled nicotine-induced PH and RV remodeling.NEW & NOTEWORTHY Chronic, inhaled nicotine causes pulmonary hypertension and right ventricular remodeling in mice. Treatment with losartan, an angiotensin II type 1 receptor antagonist, ameliorates nicotine-induced pulmonary hypertension and right ventricular remodeling. This novel finding provides preclinical evidence for the use of renin-angiotensin system-based therapies in the treatment of pulmonary hypertension, particularly in patients with a history of tobacco-product use.

V1a and V1b vasopressin receptors within the paraventricular nucleus contribute to hypertension in male rats exposed to chronic mild unpredictable stress

Depression is an independent nontraditional risk factor for cardiovascular disease and mortality. The chronic unpredictable mild stress (CMS) rat model is a validated model of depression. Within the paraventricular nucleus (PVN), vasopressin (VP) via V1aR and V1bR have been implicated in stress and neurocardiovascular dysregulation. We hypothesized that in conscious, unrestrained CMS rats versus control, unstressed rats, PVN VP results in elevated arterial pressure (MAP), heart rate, and renal sympathetic nerve activity (RSNA) via activation of V1aR and/or V1bR. Male rats underwent 4 wk of CMS or control conditions. They were then equipped with hemodynamic telemetry transmitters, PVN cannula, and left renal nerve electrode. V1aR or V1bR antagonism dose-dependently inhibited MAP after VP injection. V1aR or V1bR blockers at their ED50 doses did not alter baseline parameters in either control or CMS rats but attenuated the pressor response to VP microinjected into PVN by ∼50%. Combined V1aR and V1bR inhibition completely blocked the pressor response to PVN VP in control but not CMS rats. CMS rats required combined maximally inhibitory doses to block either endogenous VP within the PVN or responses to microinjected VP. Compared with unstressed control rats, CMS rats had higher plasma VP levels and greater abundance of V1aR and V1bR transcripts within PVN. Thus, the CMS rat model of depression results in higher resting MAP, heart rate, and RSNA, which can be mitigated by inhibiting vasopressinergic mechanisms involving both V1aR and V1bR within the PVN. Circulating VP may also play a role in the pressor response.

Pulmonary vasodilation by sildenafil in acute intermediate-high risk pulmonary embolism: a randomized explorative trial

BACKGROUND

To investigate if acute pulmonary vasodilation by sildenafil improves right ventricular function in patients with acute intermediate-high risk pulmonary embolism (PE).

METHODS

Single center, explorative trial. Patients with PE were randomized to a single oral dose of sildenafil 50 mg (n = 10) or placebo (n = 10) as add-on to conventional therapy. The time from hospital admission to study inclusion was 2.3 ± 0.7 days. Right ventricular function was evaluated immediately before and shortly after (0.5-1.5 h) randomization by right heart catheterization (RHC), trans-thoracic echocardiography (TTE), and cardiac magnetic resonance (CMR). The primary efficacy endpoint was cardiac index measured by CMR.

RESULTS

Patients had acute intermediate-high risk PE verified by computed tomography pulmonary angiography, systolic blood pressure of 135 ± 18 (mean ± SD) mmHg, increased right ventricular/left ventricular ratio 1.1 ± 0.09 and increased troponin T 167 ± 144 ng/L. Sildenafil treatment did not improve cardiac index compared to baseline (0.02 ± 0.36 l/min/m2, p = 0.89) and neither did placebo (0.00 ± 0.34 l/min/m2, p = 0.97). Sildenafil lowered mean arterial blood pressure (- 19 ± 10 mmHg, p < 0.001) which was not observed in the placebo group (0 ± 9 mmHg, p = 0.97).

CONCLUSION

A single oral dose of sildenafil 50 mg did not improve cardiac index but lowered systemic blood pressure in patients with acute intermediate-high risk PE. The time from PE to intervention, a small patient sample size and low pulmonary vascular resistance are limitations of this study that should be considered when interpreting the results.

TRIAL REGISTRATION

The trial was retrospectively registered at www.clinicaltrials.gov (NCT04283240) February 2nd 2020, https://clinicaltrials.gov/ct2/show/NCT04283240?term=NCT04283240&draw=2&rank=1 .

Lead and mercury 28 day exposure at small concentrations reduces smooth muscle relaxation by decreasing cGMP

Cardiovascular diseases are among the main causes of mortality in the world. There is evidence of cardiovascular harm after exposure to low lead or mercury concentrations, but the effects of chronic exposure to the association of low doses of these toxic metals are still unknown. This work evaluated after 4 weeks, the association effects of low concentrations of lead and mercury on blood pressure and vascular resistance reactivity. Wistar rats were exposed for 28 days to lead acetate (1st dose of 4 μg/100 g and subsequent doses of 0.05 μg /100 g/day to cover daily losses) and mercury chloride (1st dose of 2.17 μg/kg and subsequent doses of 0.03 μg/kg/ day to cover daily losses) and the control group received saline, i.m. Results showed that treatment increased blood pressure and induced left ventricular hypertrophy. The mesenteric vascular reactivity to phenylephrine and the endothelium-dependent vasodilator response assessed by acetylcholine did not change. Additionally, reduced involvement of vasoconstrictor prostanoids derived from cyclooxygenase was observed in the PbHg group. By other regulatory routes, such as potassium channels, the vessel showed a greater participation of BKCa channels, and a reduction in the participation of Kv channels and SKCa channels. The endothelium-independent smooth muscle relaxation was significantly impaired by reducing cGMP, possibly through the hyperstimulation of Phosphodiesterase-5 (PDE5). Our results suggested that exposure to low doses of lead and mercury triggers this compensatory mechanism, in response to the augment of arterial pressure.

Intravenous infusion of rocuronium bromide prolongs emergence from propofol anesthesia in rats

BACKGROUND

Neuromuscular blocking agents induce muscle paralysis via the prevention of synaptic transmission at the neuromuscular junction and may have additional effects at other sites of action. With regard to potential effects of neuromuscular blocking agents on the central nervous system, a definitive view has not been established. We investigated whether intravenous infusion of rocuronium bromide affects the emergence from propofol anesthesia.

METHODS

Using an in vivo rat model, we performed propofol infusion for 60 minutes, along with rocuronium bromide at various infusion rates or normal saline. Sugammadex or normal saline was injected at the end of the infusion period, and we evaluated the time to emergence from propofol anesthesia. We also examined the neuromuscular blocking, circulatory, and respiratory properties of propofol infusion along with rocuronium bromide infusion to ascertain possible factors affecting emergence.

RESULTS

Intravenous infusion of rocuronium bromide dose-dependently increased the time to emergence from propofol anesthesia. Sugammadex administered after propofol infusion not containing rocuronium bromide did not affect the time to emergence. Mean arterial pressure, heart rate, partial pressures of oxygen and carbon dioxide, and pH were not affected by rocuronium bromide infusion. Neuromuscular blockade induced by rocuronium bromide, even at the greatest infusion rate in the emergence experiment, was rapidly antagonized by sugammadex.

CONCLUSIONS

These results suggest that intravenous infusion of rocuronium bromide dose-dependently delays the emergence from propofol anesthesia in rats. Future studies, such as detection of rocuronium in the cerebrospinal fluid or central nervous system, electrophysiologic studies, microinjection of sugammadex into the brain, etc., are necessary to determine the mechanism of this effect.

Intensive blood pressure lowering in different age categories: insights from the Systolic Blood Pressure Intervention Trial

AIMS

The 2018 ESC/ESH guidelines for hypertension recommend differential management of patients who are <65, 65-79, and ≥80 years of age. However, it is unclear whether intensive blood pressure lowering is well-tolerated and modifies risk uniformly across the age spectrum.

METHODS AND RESULTS

SPRINT randomized 9361 high-risk adults without diabetes and age ≥50 years with systolic blood pressure 130-180 mmHg to either intensive or standard antihypertensive treatment. The primary efficacy endpoint was the composite of acute coronary syndromes, stroke, heart failure, or death from cardiovascular causes. The primary safety endpoint was composite serious adverse events. We assessed whether age modified the efficacy and safety of intensive vs. standard blood pressure lowering using Cox proportional-hazards regression and restricted cubic splines. In all, 3805 (41%), 4390 (47%), and 1166 (12%) were <65, 65-79, and ≥80 years. Mean age was similar between the two study groups (intensive group 67.9 ± 9.4 years vs. standard group 67.9 ± 9.5 years; P = 0.94). Median follow-up was 3.3 years. In multivariable models, age was linearly associated with the risk of stroke (P < 0.001) and non-linearly associated with the risk of primary efficacy events, death from cardiovascular causes, death from any cause, heart failure, and serious adverse events (P < 0.001). The safety and efficacy of intensive blood pressure lowering were not modified by age, whether tested continuously or categorically (P > 0.05).

CONCLUSION

In SPRINT, the benefits and risks of intensive blood pressure lowering did not differ according to the age categories proposed by the ESC/ESH guidelines for hypertension.

TRIAL REGISTRATION

SPRINT (Systolic Blood Pressure Intervention Trial); ClinicalTrials.gov Identifier: NCT01206062, https://clinicaltrials.gov/ct2/show/NCT01206062.

Glutamine's protection against brain damage in septic rats via increased protein oxygen-N-acetylglucosamine modification

OBJECTIVE

This study aimed to observe the effect of glutamine (Gln) on brain damage in septic rats and explore its possible mechanism.

METHODS

Ninety-three Sprague-Dawley rats were randomly divided into five groups: sham operation group, sepsis group, Gln-treated group, quercetin/Gln-treated group, and alloxan/Gln-treated group. The rats in each group were continuously monitored for mean arterial pressure (MAP) and heart rate changes for 16 h. Neuroreflex scores were measured 24 h after surgery. The water content of the brain tissue was measured. Plasma neuron enolase and cysteine protease-3 were measured using the ELISA. The expression levels of heat shock protein 70 (HSP70) and oxygen-N-acetylglucosamine (O-GlcNAc) were determined by western blot analysis. Finally, the brain tissue was observed via hematoxylin and eosin staining.

RESULTS

The brain tissue water content, plasma neuron enolase content, brain tissue cysteine protease-3 content, and nerve reflex score were significantly lower in the Gln-treated group than in the sepsis group (P < 0.05). At the same time, the pathological brain tissue damage in the Gln-treated group was also significantly reduced. It is worth noting that the expression of HSP70 and the protein O-GlcNAc modification levels in the Gln-treated group were significantly elevated than the levels in the sepsis group (P < 0.05), and reversed by pretreatment with the HSP and O-GlcNAc inhibitors quercetion and alloxan.

CONCLUSIONS

Gln can attenuate brain damage in rats with sepsis, which may be associated with increased protein O-GlcNAc modification.

HDAC5 inhibition reduces angiotensin II-induced vascular contraction, hypertrophy, and oxidative stress in a mouse model

Non-specific histone deacetylase (HDAC) inhibition reduces high blood pressure in essential hypertensive animal models. However, the exact HDAC isoforms that play a critical role in controlling hypertension are not known. Here, we investigated the role of HDAC5 in vascular contraction, hypertrophy, and oxidative stress in the context of angiotensin II (Ang II)-induced hypertension. Genetic deletion of HDAC5 and treatment with class IIa HDAC inhibitors (TMP269 and TMP195) prevented Ang II-induced increases in blood pressure and arterial wall thickness. Hdac5-knockout mice were also resistant to the thromboxane A2 agonist (U46619)-induced vascular contractile response. Furthermore, the expression of Rho-associated protein kinase (ROCK) 2 was downregulated in the aortas of Ang II-treated Hdac5-knockout mice. Knockdown of HDAC5, RhoA, or ROCK2 reduced collagen gel contraction, whereas silencing of ROCK1 increased it. VSMC hypertrophy reduced on knocking down HDAC5, ROCK1, and ROCK2. Here we showed that genetic deletion of HDAC5 and pharmacological inhibition of class IIa HDACs ameliorated Ang II-induced ROS generation. Moreover, ROCK1 and ROCK2, the downstream targets of HDAC5, influenced ROS generation. The relative protein levels of HDAC5, ROCK1, and ROCK2 were increased both in the cytoplasm and nuclear fraction in response to Ang II stimulation in vascular smooth muscle cells. Inhibition of HDAC5 expression or activity reduced vascular hypertrophy, vasoconstriction, and oxidative stress in the Ang II-induced hypertension model. These findings indicate that HDAC5 may serve as a potential target in the treatment of hypertension.

Temporal effects of barbiturate coma on intracranial pressure and compensatory reserve in children with traumatic brain injury

Background

The aim was to study the effects of barbiturate coma treatment (BCT) on intracranial pressure (ICP) and intracranial compensatory reserve (RAP index) in children (< 17 years of age) with traumatic brain injury (TBI) and refractory intracranial hypertension (RICH).

Methods

High-resolution monitoring data were used to study the effects of BCT on ICP, mean arterial pressure (MAP), cerebral perfusion pressure (CPP), and RAP index. Four half hour long periods were studied: before bolus injection and at 5, 10, and 24 hours thereafter, respectively, and a fifth tapering period with S-thiopental between < 100 and < 30 μmol/L. S-thiopental concentrations and administered doses were registered.

Results

Seventeen children treated with BCT 2007–2017 with high-resolution data were included; median age 15 (range 6–17) and median Glasgow coma score 7 (range 3–8). Median time from trauma to start of BCT was 44.5 h (range 2.5–197.5) and from start to stop 99.0 h (range 21.0–329.0). Median ICP was 22 (IQR 20–25) in the half hour period before onset of BCT and 16 (IQR 11–20) in the half hour period 5 h later (p = 0.011). The corresponding figures for CPP were 65 (IQR 62–71) and 63 (57–71) (p > 0.05). The RAP index was in the half hour period before onset of BCT 0.6 (IQR 0.1–0.7), in the half hour period 5 h later 0.3 (IQR 0.1–0.7) (p = 0.331), and in the whole BCT period 0.3 (IQR 0.2–0.4) (p = 0.004). Eighty-two percent (14/17) had favorable outcome (good recovery = 8 patients and moderate disability = 6 patients).

Conclusion

BCT significantly reduced ICP and RAP index with preserved CPP. BCT should be considered in case of RICH.

Chronic Infusion of Astaxanthin Into Hypothalamic Paraventricular Nucleus Modulates Cytokines and Attenuates the Renin-Angiotensin System in Spontaneously Hypertensive Rats

ABSTRACT

Oxidative stress, the renin-angiotensin system (RAS), and inflammation are some of the mechanisms involved in the pathogenesis of hypertension. The aim of this study is to examine the protective effect of the chronic administration of astaxanthin, which is extracted from the shell of crabs and shrimps, into hypothalamic paraventricular nucleus (PVN) in spontaneously hypertensive rats. Animals were randomly assigned to 2 groups and treated with bilateral PVN infusion of astaxanthin or vehicle (artificial cerebrospinal fluid) through osmotic minipumps (Alzet Osmotic Pumps, Model 2004, 0.25 μL/h) for 4 weeks. Spontaneously hypertensive rats had higher mean arterial pressure and plasma level of norepinephrine and proinflammatory cytokine; higher PVN levels of reactive oxygen species, NOX2, NOX4, IL-1β, IL-6, ACE, and AT1-R; and lower PVN levels of IL-10 and Cu/Zn SOD, Mn SOD, ACE2, and Mas receptors than Wistar-Kyoto rats. Our data showed that chronic administration of astaxanthin into PVN attenuated the overexpression of reactive oxygen species, NOX2, NOX4, inflammatory cytokines, and components of RAS within the PVN and suppressed hypertension. The present results revealed that astaxanthin played a role in the brain. Our findings demonstrated that astaxanthin had protective effect on hypertension by improving the balance between inflammatory cytokines and components of RAS.

Vasorelaxant and Antihypertensive Effects of Mentha pulegium L. in Rats: An In vitro and In vivo Approach

Aims The aim of the study was to investigate the effect of aqueous aerial part extract of Mentha pulegium L. (Pennyrile) (MPAE) on arterial pressure parameters in rats.

BACKGROUND

Mentha pulegium is a medicinal plant used to treat hypertension in the Moroccon population.

METHODS

In the current study, MPAE was prepared and its antihypertensive activity was pharmacologically investigated. L-NAME-hypertensive and normotensive rats received MPAE (180 and 300 mg/kg) orally for six hours for acute experiment and during seven days for the sub-chronic treatment. Thereafter, systolic, diastolic, mean arterial blood pressure and heart rate were evaluated. In the in vitro experiment, isolated denuded and intact thoracic aortic rings were suspended in a tissue bath system and the tension changes were recorded.

RESULTS

A fall in blood pressure was observed in L-NAME-induced hypertensive treated with MPAE. The extract also produced a dose-dependent relaxation of aorta pre-contracted with NE and KCl. The study showed that the vasorelaxant ability of MPAE seems to be exerted through the blockage of extracellular Ca2+ entry.

CONCLUSION

The results demonstrate that the extract of pennyrile exhibits antihypertensive activity. In addition, the effect may be, at least in part, due to the dilation of blood vessels via blockage of Ca2+ channels.

Bacillus anthracis edema toxin inhibits hypoxic pulmonary vasoconstriction via edema factor and cAMP-mediated mechanisms in isolated perfused rat lungs

Bacillus anthracis edema toxin (ET) inhibited lethal toxin-stimulated pulmonary artery pressure (Ppa) and increased lung cAMP levels in our previous study. We therefore examined whether ET inhibits hypoxic pulmonary vasoconstriction (HPV). Following baseline hypoxic measures in isolated perfused lungs from healthy rats, compared with diluent, ET perfusion reduced maximal Ppa increases (mean ± SE percentage of maximal Ppa increase with baseline hypoxia) during 6-min hypoxic periods (FIO2 = 0%) at 120 min (16 ± 6% vs. 51 ± 6%, P = 0.004) and 180 min (11.4% vs. 55 ± 6%, P = 0.01). Protective antigen-mAb (PA-mAb) and adefovir inhibit host cell edema factor uptake and cAMP production, respectively. In lungs perfused with ET following baseline measures, compared with placebo, PA-mAb treatment increased Ppa during hypoxia at 120 and 180 min (56 ± 6% vs. 10 ± 4% and 72 ± 12% vs. 12 ± 3%, respectively, P ≤ 0.01) as did adefovir (84 ± 10% vs. 16.8% and 123 ± 21% vs. 26 ± 11%, respectively, P ≤ 0.01). Compared with diluent, lung perfusion with ET for 180 min reduced the slope of the relationships between Ppa and increasing concentrations of endothelin-1 (ET-1) (21.12 ± 2.96 vs. 3.00 ± 0.76 × 108 cmH2O/M, P < 0.0001) and U46619, a thromboxane A2 analogue (7.15 ± 1.01 vs. 3.74 ± 0.31 × 107 cmH2O/M, P = 0.05) added to perfusate. In lungs isolated from rats after 15 h of in vivo infusions with either diluent, ET alone, or ET with PA-mAb, compared with diluent, the maximal Ppa during hypoxia and the slope of the relationship between change in Ppa and ET-1 concentration added to the perfusate were reduced in lungs from animals challenged with ET alone (P ≤ 0.004) but not with ET and PA-mAb together (P ≥ 0.73). Inhibition of HPV by ET could aggravate hypoxia during anthrax pulmonary infection.NEW & NOTEWORTHY The most important findings here are edema toxin's potent adenyl cyclase activity can interfere with hypoxic pulmonary vasoconstriction, an action that could worsen hypoxemia during invasive anthrax infection with lung involvement. These findings, coupled with other studies showing that lethal toxin can disrupt pulmonary vascular integrity, indicate that both toxins can contribute to pulmonary pathophysiology during infection. In combination, these investigations provide a further basis for the use of antitoxin therapies in patients with worsening invasive anthrax disease.

Rapid Switch From Subcutaneous to Intravenous Treprostinil in Precapillary Pulmonary Hypertension by Pump Implantation

ABSTRACT

Limited data are available on the transition from subcutaneous to intravenous prostacyclin in precapillary pulmonary hypertension. We performed a retrospective analysis of all patients who were switched from subcutaneous to intravenous treprostinil with an implantable infusion pump. We included 85 consecutive, clinically stable patients (mean age 66 years and range 16-85), who had been treated with subcutaneous treprostinil for mean 9 months (range 1-78) before pump implantation. An interdisciplinary expert panel defined standards for this procedure before the first implantation. As the first patient experienced a significant hypotensive episode indicating treprostinil overdose postoperatively, the time span to stop subcutaneous treprostinil was reduced to 60 minutes for all following patients. No events associated with the switch from subcutaneous to intravenous treprostinil were observed during postoperative hospital stay in 84 (98.8%) patients. Taking into account a likely depot effect of subcutaneous treprostinil patients can safely be switched to the intravenous route by the implantation of an infusion pump.

Mean arterial pressure maintenance following spinal cord injury: Does meeting the target matter?

INTRODUCTION

Neurosurgical guidelines recommend maintaining mean arterial pressure (MAP) between 85 and 90 mm Hg following acute spinal cord injury (SCI). In our hospital, SCI patients receive orders for MAP targeting for 72 hours following admission, but it is unclear how often the patient's MAP meets the target and whether or not this affects outcome. We hypothesized that the proportion of MAP measurements ≥85 mm Hg would be associated with neurologic recovery.

METHODS

Spinal cord injury patients with blunt mechanism of injury admitted between 2014 and 2019 were identified from the registry of a level 1 trauma center. Proportion of MAP values ≥85 mm Hg was calculated for each patient. Neurologic improvement, as measured by positive change in American Spinal Injury Association (ASIA) impairment scale by ≥1 level from admission to discharge was evaluated with respect to proportion of elevated MAP values.

RESULTS

A total of 136 SCI patients were evaluated. Average proportion of elevated MAP values was 75%. Admission ASIA grades were as follows: A, 30 (22.1%); B, 20 (14.7%); C, 28 (20.6%); and D, 58 (42.6%). One hundred six patients (77.9%) required vasopressors to elevate MAP (ASIA A, 86.7%; B, 95.0%; C, 92.9%; D, 60.3%). Forty patients (29.4%) were observed to have improvement in ASIA grade by discharge (admission ASIA A, 15%; B, 33%; C, 40%; D, 13%). The proportion of elevated MAP values was higher for patients with neurologic improvement (0.81 ± 0.15 vs. 0.72 ± 0.25, p = 0.014). Multivariate modeling demonstrated a significant association between proportion of elevated MAP values and neurologic improvement (p = 0.028). An interaction revealed this association to be moderated by vasopressor dose (p = 0.032).

CONCLUSION

The proportion of MAP measurements ≥85 mm Hg was determined to be an independent predictor of neurologic improvement. Increased vigilance regarding MAP maintenance above 85 mm Hg is warranted to optimize neurologic recovery following SCI.

LEVEL OF EVIDENCE

Therapeutic/care management, level IV.

Pharmacophore modeling, design, and synthesis of potent antihypertensives, oxazolo/thiazolo-[3,2-a]-pyrimidin-3(2H)-one, and 1,5-dihydroimidazo-[1,2-a]-pyrimidin-3(2H)-one derivatives: A pilot trial

An improved pharmacophore model, molecular properties, geometric analyses, and SAR led to synthesize oxazolo/thiazolo-[3,2-a]-pyrimidin-3(2H)-one, and 1,5-dihydroimidazo-[1,2-a]-pyrimidin-3(2H)-one derivatives exhibiting potent anti-hypertensive activity. The 6-ethoxycarbonyl-2,7-dimethyl-5-phenyl-1,5-dihydroimidazo[3,2-a]pyrimidin-3(2H)-one (4g), and 6-ethoxycarbonyl-2,7-dimethyl-5-(3-methyl-phenyl)-1,5-dihydroimidazo[3,2-a]pyrimidin-3(2H)-one (4h) showed significant reduction in mean arterial blood pressure (MABP, mm/Hg) of 79.78%, and 92.95% in 6 and 12 h durations, respectively, at 1.5 mg/kg body-weight dose, while at 3.0 mg/kg body-weight dose, the MABP reduction was achieved at 95.46%, and 92.02%, respectively, in 6 and 12 h durations, as compared to the standard drug, nifedipine.

Clinical observation of the combined use of propofol and etomidate in painless gastroscopy

OBJECTIVE

This study is aims to compare the anesthetic safety of propofol combined with etomidate for painless gastroscopy.

METHODS

Three hundred patients undergoing painless gastroscopy were randomly assigned to P, PE1, and PE2 groups. Patients were anesthetized with propofol (P group) or propofol combined with etomidate (volume ratio 1: 1, PE1 group; volume ratio 2: 1, PE2 group). The hemodynamics and adverse reactions were observed. The sleep quality satisfaction and nature of dreams were recorded.

RESULTS

Compared with pre-anesthesia, the mean arterial pressure and heart rate of the 3 groups were significantly slower during the examination and at the end of the examination. PE1 group had a higher incidence of muscle spasm, body moving, choking, and deglutition. The incidence of hypoxemia and injection pain was higher in P group. P and PE2 group had higher sleep quality satisfaction and dream incidence after awaking. However, there was no difference in the nature of dreams among 3 groups.

CONCLUSION

Our data indicate that the combination of 10 ml 1.0% propofol and 5 ml 0.2% etomidate for painless gastroscopy reduces adverse reactions while not affecting the patients respiratory function. Moreover, it is safe and effective, which is worthy of clinical application and promotion.

Comparison of bispectral index-guided and fixed-gas concentration techniques in desflurane and remifentanil anesthesia: A randomized controlled trial

Anesthesia with desflurane and remifentanil can be maintained with either fixed or titrated desflurane concentration. We hypothesized that the fixed-gas concentration (FG) method would reduce the number of anesthetic titrations without hypnotic and hemodynamic instability compared to the bispectral index (BIS)-guided (BG) method. Forty-eight patients were randomly allocated to the FG or BG groups. In the FG group, desflurane vaporizer setting was fixed at 1 age-corrected minimum alveolar concentration (MAC). In the BG group, desflurane was titrated to target a BIS level at 50. Remifentanil was titrated to maintain a systolic arterial pressure (SAP) of 120 mmHg in both groups. Our primary endpoint was the hypnotic stability measured by the wobble of BIS in performance analysis, and the secondary endpoints included the wobble of SAP, mean BIS value during surgery, and the number of anesthetic titrations. The BIS in the FG group showed significantly less wobble (3.9 ± 1.1% vs 5.5 ± 1.5%, P <0.001) but lower value (33 ± 6 vs 46 ± 7, P <0.001) than BG group. The wobble of SAP showed no difference between groups [median (inter-quartile range), 5.0 (4.1-7.5)% vs 5.2 (4.2-8.3)%, P = 0.557]. The numbers of anesthetic titrations in the FG group were significantly lower than the BG group (0 ± 0 vs 8 ± 5, P<0.001 for desflurane, 13 ± 13 vs 22 ± 17, P = 0.047 for remifentanil). Less wobble in BIS and reduced anesthetic titration without hemodynamic instability during the FG technique may be practical in balanced anesthesia using desflurane and remifentanil anesthesia. Clinical trial: This study was registered at ClinicalTrials.gov (NCT02283866).

The impact of hypertonic saline on cerebrovascular reactivity and compensatory reserve in traumatic brain injury: an exploratory analysis

Background

Intravenous hypertonic saline is utilized commonly in critical care for treatment of acute or refractory elevations of intracranial pressure (ICP) in traumatic brain injury (TBI) patients. Though there is a clear understanding of the general physiological effects of a hypertonic saline solution over long periods of time, smaller epoch effects of hypertonic saline (HTS) have not been thoroughly analyzed. The aim of this study was to perform a direct evaluation of the high-frequency response of HTS on the cerebrovascular physiological responses in TBI.

Methods

We retrospectively reviewed our prospectively maintained adult TBI database for those with archived high-frequency cerebral physiology and available HTS treatment information. We evaluated different epochs of physiology around HTS bolus dosing, comparing pre- with post-HTS. We assessed for changes in slow fluctuations in ICP, pulse amplitude of ICP (AMP), cerebral perfusion pressure (CPP), mean arterial pressure (MAP), cerebrovascular reactivity (as measured through pressure reactivity index (PRx)), and cerebral compensatory reserve (correlation (R) between AMP (A) and ICP (P)). Comparisons of mean measures and percentage time above clinically relevant thresholds for the physiological parameters were compared pre- and post-HTS using descriptive statistics and Mann-Whitney U testing. We assessed for subgroups of physiological responses using latent profile analysis (LPA).

Results

Fifteen patients underwent 69 distinct bolus infusions of hypertonic saline. Apart from the well-documented decrease in ICP, there was also a reduction in AMP. The analysis of cerebrovascular reactivity response to HTS solution had two main effects. For patients with grossly impaired cerebrovascular reactivity pre-HTS (PRx > + 0.30), HTS bolus led to improved reactivity. However, for those with intact cerebrovascular reactivity pre-HTS (PRx < 0), HTS bolus demonstrated a trend towards more impaired reactivity. This indicates that HTS has different impacts, dependent on pre-bolus cerebrovascular status. There was no significant change in metrics of cerebral compensatory reserve. LPA failed to demonstrate any subgroups of physiological responses to HTS administration.

Conclusions

The direct decrease in ICP and AMP confirms that a bolus dose of a HTS solution is an effective therapeutic agent for intracranial hypertension. However, in patients with intact autoregulation, hypertonic saline may impair cerebral hemodynamics. These findings regarding cerebrovascular reactivity remain preliminary and require further investigation.

Electronic supplementary material

The online version of this article (10.1007/s00701-020-04579-0) contains supplementary material, which is available to authorized users.

Pollutants and nutrition: Are methylmercury effects on blood pressure and lipoprotein profile comparable to high-fat diet in mice?

Human exposure to methylmercury (MeHg) due to contaminated fish intake as part of a high-fat (HFD), high-carbohydrate diets is a reality today for many populations. HFD is associated with hypertension and hyperlipidemia, primary cardiovascular disease (CVD) risk factors. Some studies suggest that MeHg induces those risk factors. We evaluated the effect of MeHg exposure in mice fed with HFD or control diet for eight weeks. In the last experimental 15 days, the half group received a MeHg solution (20 mg/L) replacing water. Blood pressure (BP), heart rate, lipoprotein concentrations, and paraoxonase activity were evaluated. Liver cholesterol, triacylglycerol, and IBA-1+ cells, as well as transcriptional levels of genes related to lipid metabolism and inflammatory response, were also assessed. HFD and both MeHg groups presented increased BP and total cholesterol (TC). In the liver, HFD but not MeHg was related to an increase in TC. Also, MeHg intoxication reduced paraoxonase activity regardless of diet. MeHg intoxication and HFD increased steatosis and the number of IBA-1+ cells and modified some gene transcripts associated with lipid metabolism. In conclusion, we demonstrated that MeHg effects on CVD risk factors resemble those caused by HFD.

Interplay of the adenosine system and NO in control of renal haemodynamics and excretion: Comparison of normoglycaemic and streptozotocin diabetic rats

The adenosine (Ado) system may participate in regulation of kidney function in diabetes mellitus (DM), therefore we explored its role and interrelation with NO in the control of renal circulation and excretion in normoglycemic (NG) and streptozotocin-diabetic (DM) rats. Effects of theophylline (Theo), a non-selective Ado receptor antagonist, were examined in anaesthetized NG or in streptozotocin induced diabetic (DM) rats, untreated or after blockade of NO synthesis with l-NAME. We measured arterial blood pressure (MABP), whole kidney blood flow and renal regional flows: cortical and outer- and inner-medullary (IMBF), determined as laser-Doppler fluxes. Renal excretion of water, total solutes and sodium and in situ renal tissue NO signal (selective electrodes) were also determined. Theo experiments disclosed minor baseline vasoconstrictor and vasodilator tone in the kidney of NG and DM rats, respectively. NO blockade increased baseline MABP and decreased renal haemodynamics, similarly in NG and DM rats, indicating comparable vasodilator influence of NO in the two groups. Unexpectedly, in all rats with intact NO synthesis, Ado receptor blockade increased kidney tissue NO. In NO-deficient NG and DM rats, Ado receptor blockade induced comparable renal vasodilatation, suggesting similar vasoconstrictor influence of the Ado system. However, DM rats showed an unexplained association of decreased MABP and IMBF and increased NO signal. Higher baseline renal excretion in DM rats indicated inhibition of renal tubular reabsorption due to the prevalence of natriuretic A2 over antinatriuretic A1 receptors. In conclusion, the experiments provided new insights in functional interrelation of adenosine and NO in normoglycaemia and streptozotocin-diabetes.

Effects of maternal protein restriction on central and peripheral renin-angiotensin systems in male rat offspring

AIMS

We investigated the involvement of the renin angiotensin system (RAS) on the cardiorespiratory control in rats from dams fed with a low-protein diet.

MAIN METHODS

Male offspring were obtained from dams fed a normoprotein diet (NP, 17% casein) and low-protein diet (LP, 8% casein) during pregnancy and lactation. Direct measurements of arterial pressure (AP), heart rate (HR) and respiratory frequency (RF) were recorded in awake 90-day-old at resting and after losartan potassium through either intracerebroventricular (ICV) microinjections or intravenous (IV) administration. Cardiovascular variability was evaluated by spectral analysis. Peripheral chemoreflex sensitivity was assessed through the potassium cyanide (KCN; 40 μg/0.1 ml/rat, IV). Gene expression was evaluated by qPCR, and MAPK (Mitogen Activated Protein Kinase) expression was evaluated by western blot.

KEY FINDINGS

The LP offspring had higher mean AP (MAP) and RF than NP offspring. In the spectral analysis, the LP rats also showed higher low frequency of systolic AP (NP: 2.7 ± 0.3 vs. LP: 5.0 ± 1.0 mmHg). After ICV losartan, MAP and RF in LP rats remained higher than those in NP rats, but without changes in HR. The peripheral chemoreflex was similar between the groups. LP group had lower gene expression of Rac1 (Ras-related C3 botulinum toxin substrate 1) (NP: 1.13 ± 0.06 vs. LP: 0.88 ± 0.08). Peripherally, LP rats had larger delta of MAP after IV losartan (NP: -9.8 ± 2 vs. LP: -23 ± 6 mmHg), without changes in HR and RF.

SIGNIFICANCE

In rats, the RAS participates peripherally, but not centrally, in the maintenance of arterial hypertension in male offspring induced by maternal protein restriction.

Effects of stem bark aqueous extract of Fagara tessmannii Engl (Rutaceae) on cardiovascular risks related to monosodium glutamate-induced obesity in rat: In vivo and in vitro assessments

ETHNOPHARMACOLOGICAL RELEVANCE

Fagara tessmannii is a shrub of the African rainforests in South-West, Centre, South and East provinces in Cameroon. It is used in traditional medicine for the treatment of tumors, swellings, inflammation, gonorrhoea, schistosomiasis, antifungal, heart diseases and as anti-hypertensive.

AIM OF THE STUDY

We investigated the potential effects of F. tessmannii on cardiovascular risk related to monosodium glutamate-induced obesity.

MATERIALS AND METHODS

Monosodium glutamate (MSG, 4 mg/g/day) was injected subcutaneously to newborn Wistar rats for the four consecutive first days of their life and on the 6th, 8th and 10th day after birth. After 21 weeks, obese rats were treated orally with F. tessmannii (100 or 200 mg/kg/day), orlistat (10 mg/kg/day) or telmisartan (10 mg/kg/day) for 6 weeks. Body weight, obesity, body mass index (BMI), Lee index, insulin sensitivity and glucose tolerance, blood pressure, lipid profile as a Coronary Risk Index (CRI), and reactivity of isolated thoracic aorta were evaluated.

RESULTS

In addition to significantly decrease body weight (17.60% and 20.34%), BMI, Lee's index, retroperitoneal fat, total adiposity, and coronary risk indicators, F. tessmannii has significantly decreased insulin resistance and hyperglycemia and high blood pressure observed in MSG-obese rats. The high contractility to phenylephrine as well as the hypersensitivity to sodium nitroprusside (a nitric oxide-donor), observed in MSG aortic rings were significantly reduced by the F. tessmannii extract. Enhanced serum Na⁺ and Cl^- levels and decreased K⁺ observed in obese rats were also significantly reversed after F. tessmannii treatment.

CONCLUSIONS

F. tessmannii fights against obesity and associated cardiovascular risks by modulating production and vascular responsiveness to vasoactive factors, monitoring premature aging. F. tessmannii promotes the loss of ectopic fat and other fatty tissues, the sensitivity of the peripherical tissues to insulin, the energy expenditure and the renovascular decompression and regulates ions movement which prevents hypertension.

Exercise augments the modulatory effects of vitamin E on pre-diabetes-induced aortopathy: a potential role of adiponectin

Background: We tested the hypothesis that vitamin E may protect against pre-diabetes-induced aortic injury (aortopathy), and exercise can augment the action of vitamin E.Material and methods: Rats were either fed with a high fat and fructose diet (HFD) (model group) or a standard laboratory chow (control group) for 15 weeks before being sacrificed. The three protective groups were treated with vitamin E (HFD + Vit E), swimming exercises (HFD + Ex), and vitamin E plus swimming exercises (HFD + VitE + Ex), respectively.Results: Aortopathy was developed in the model group as demonstrated by substantial tissue ultrastructural alterations, which were partially protected by vitamin E and effectively protected with vitamin E plus swim exercise. Also, swimming exercises significantly (p < .05) increased the modulatory effects of vitamin E on dyslipidemia, insulin resistance, blood pressure, oxidative stress, inflammation, leptin, and adiponectin, except coagulation and thrombosis.Conclusions: Swim exercise augments the protective effects of vitamin E in a pre-diabetic animal model.

5-HT3 blockade does not attenuate postspinal blood pressure change in cesarean section: A case-control study

Spinal anesthesia (SpA) for elective caesarean section (CS) is often accompanied by clinically relevant arterial hypotension. The Bezold-Jarisch reflex, causing postspinal hypotension, has been shown to be antagonized by serotonin type 3 (5-HT3) blockade. Our aim was to assess if routine prophylactic administration of the 5-HT3 antagonist ondansetron (ODS) attenuates postspinal change in maternal blood pressure.Elective CS under SpA were retrospectively analyzed. Eighty parturients having routinely received 8 mg ODS prior to SpA were compared with 80 patients having not (control group).Mean arterial blood pressure significantly decreased from baseline to the postspinal period (P < .0001) without differences in blood pressure decreases between the 2 groups. This also applied to the heart rate. Overall use of cafedrine/theodrenaline was higher in the ODS group (0.8 (0.4-1.6) mL vs 0.8 (0-1.0) mL in the control group, P = .01). APGAR values showed a presumably clinically irrelevant decrease in control group compared with the ODS group.Our results suggest that routine administration of ODS in a dosage of 8 mg does not effectively attenuate postspinal change in maternal blood pressure during CS in our setting. Given the wide variability of anesthetic techniques, only large prospective and randomized multicenter trials will ultimately serve to elucidate this issue.