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Potential Role of Fourier Transform Infrared Spectroscopy as a Screening Approach for Breast Cancer. APPLIED SPECTROSCOPY 2023; 77:405-417. [PMID: 36703259 DOI: 10.1177/00037028231156194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Breast cancer is a heterogeneous disease, and its spread involves a succession of clinical and pathological stages. Screening is predominantly based on mammography, which has critical limitations related to the effectiveness and production of false-positive or false-negative results, generating discomfort and low adherence. In this context, infrared with attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopy emerges as a non-destructive sample tool, which is non-invasive, label-free, has a low operating-cost, and requires only a small amount of sample, including liquid plasma samples. We sought to evaluate the clinical applicability of ATR FT-IR in breast cancer screening. ATR FT-IR spectroscopy through its highest potential spectral biomarker could distinguish, by liquid plasma biopsy, breast cancer patients and healthy controls, obtaining a sensitivity of 97%, specificity of 93%, a receiver operating characteristic ROC curve of 97%, and a prediction accuracy of 94%. The main variance between the groups was mainly in the band 1511 cm-1 of the control group, 1502 and 1515 cm-1 of the cancer group, which are the peaks of the bands referring to proteins and amide II. ATR FT-IR spectroscopy has demonstrated to be a promising tool for breast cancer screening, given its time efficiency, cost of approach, and its high ability to distinguish between the liquid plasma samples of breast cancer patients and healthy controls.
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Estrogen Therapy Worsens Cardiac Function and Remodeling and Reverses the Effects of Exercise Training After Myocardial Infarction in Ovariectomized Female Rats. Front Physiol 2018; 9:1242. [PMID: 30233413 PMCID: PMC6134041 DOI: 10.3389/fphys.2018.01242] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 08/16/2018] [Indexed: 01/24/2023] Open
Abstract
There is an increase in the incidence of cardiovascular events such as myocardial infarction (MI) after menopause. However, the use of estrogen therapy (E2) remains controversial. The aim of this study was to evaluate the effects of E2, alone and combined with exercise training (ET), on cardiac function and remodeling in ovariectomized (OVX) rats after MI. Wistar female rats underwent ovariectomy, followed by MI induction were separated into five groups: S; MI; MI+ET; MI+E2; and MI+ET+E2. Fifteen days after MI or sham surgery, treadmill ET and/or estrogen therapy [17-β estradiol-3-benzoate (E2), s.c. three times/week] were initiated and maintained for 8 weeks. After the treatment and/or training period, the animals underwent cardiac hemodynamic evaluation through catheterization of the left ventricle (LV); the LV systolic and diastolic pressures (LVSP and LVEDP, respectively), maximum LV contraction and relaxation derivatives (dP/dt+ and dP/dt−), and isovolumic relaxation time (Tau) were assessed. Moreover, histological analyses of the heart (collagen and hypertrophy), cardiac oxidative stress [advanced oxidation protein products (AOPPs)], pro- and antioxidant protein expression by Western blotting and antioxidant enzyme activity in the heart were evaluated. The MI reduced the LVSP, dP/dt+ and dP/dt− but increased the LVEDP and Tau. E2 did not prevent the MI-induced changes in cardiac function, even when combined with ET. An increase in the dP/dt+ was observed in the E2 group compared with the MI group. There were no changes in collagen deposition and myocyte hypertrophy caused by the treatments. The increases in AOPP, gp91-phox, and angiotensin II type 1 receptor expression induced by MI were not reduced by E2. There were no changes in the expression of catalase caused by MI or by the treatments, although, a reduction in superoxide dismutase (SOD) expression occurred in the groups subjected to E2 treatment. Whereas there were post-MI reductions in activities of SOD and catalase enzymes, only that of SOD was prevented by ET. Therefore, we conclude that E2 therapy does not prevent the MI-induced changes in cardiac function and worsens parameters related to cardiac remodeling. Moreover, E2 reverses the positive effects of ET when used in combination, in OVX infarcted female rats.
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Swimming training prevents coronary endothelial dysfunction in ovariectomized spontaneously hypertensive rats. ACTA ACUST UNITED AC 2017; 50:e5495. [PMID: 28099583 PMCID: PMC5264533 DOI: 10.1590/1414-431x20165495] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 11/10/2016] [Indexed: 11/22/2022]
Abstract
Estrogen deficiency and hypertension are considered major risk factors for the
development of coronary heart disease. On the other hand, exercise training is
considered an effective form to prevent and treat cardiovascular diseases. However,
the effects of swimming training (SW) on coronary vascular reactivity in female
ovariectomized hypertensive rats are not known. We aimed to evaluate the effects of
SW on endothelium-dependent coronary vasodilation in ovariectomized hypertensive
rats. Three-month old spontaneously hypertensive rats (SHR, n=50) were divided into
four groups: sham (SH), sham plus swimming training (SSW), ovariectomized (OVX), and
ovariectomized plus swimming training (OSW). The SW protocol (5 times/week, 60
min/day) was conducted for 8 weeks. The vasodilatory response was measured in
isolated hearts in the absence and presence of a nitric oxide synthase inhibitor
(L-NAME, 100 µM). Cardiac oxidative stress was evaluated in situ by
dihydroethidium fluorescence, while the expression of antioxidant enzymes (SOD-2 and
catalase) and their activities were assessed by western blotting and
spectrophotometry, respectively. Vasodilation in SHR was significantly reduced by
OVX, even in the presence of L-NAME, in conjunction with an increased oxidative
stress. These effects were prevented by SW, and were associated with a decrease in
oxidative stress. Superoxide dismutase 2 (SOD-2) and catalase expression increased
only in the OSW group. However, no significant difference was found in the activity
of these enzymes. In conclusion, SW prevented the endothelial dysfunction in the
coronary bed of ovariectomized SHR associated with an increase in the expression of
antioxidant enzymes, and therefore may prevent coronary heart disease in hypertensive
postmenopausal women.
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Hormonal therapy with estradiol and drospirenone improves endothelium-dependent vasodilation in the coronary bed of ovariectomized spontaneously hypertensive rats. ACTA ACUST UNITED AC 2016; 49:e4655. [PMID: 26577845 PMCID: PMC4678653 DOI: 10.1590/1414-431x20154655] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 06/29/2015] [Indexed: 02/07/2023]
Abstract
Drospirenone (DRSP) is a progestin with anti-aldosterone properties and it reduces
blood pressure in hypertensive women. However, the effects of DRSP on
endothelium-dependent coronary vasodilation have not been evaluated. This study
investigated the effects of combined therapy with estrogen (E2) and DRSP on
endothelium-dependent vasodilation of the coronary bed of ovariectomized (OVX)
spontaneously hypertensive rats. Female spontaneously hypertensive rats (n=87) at 12
weeks of age were randomly divided into sham operated (Sham), OVX, OVX treated with
E2 (E2), and OVX treated with E2 and DRSP (E2+DRSP) groups. Hemodynamic parameters
were directly evaluated by catheter insertion into the femoral artery.
Endothelium-dependent vasodilation in response to bradykinin in the coronary arterial
bed was assessed using isolated hearts according to a modified Langendorff method.
Coronary protein expression of endothelial nitric oxide synthase and estrogen
receptor alpha (ER-α) was assessed by Western blotting. Histological slices of
coronary arteries were stained with hematoxylin and eosin, and morphometric
parameters were analyzed. Oxidative stress was assessed in situ by
dihydroethidium fluorescence. Ovariectomy increased systolic blood pressure, which
was only prevented by E2+DRSP treatment. Estrogen deficiency caused endothelial
dysfunction, which was prevented by both treatments. However, the vasodilator
response in the E2+DRSP group was significantly higher at the three highest
concentrations compared with the OVX group. Reduced ER-α expression in OVX rats was
restored by both treatments. Morphometric parameters and oxidative stress were
augmented by OVX and reduced by E2 and E2+DRSP treatments. Hormonal therapy with E2
and DRSP may be an important therapeutic option in the prevention of coronary heart
disease in hypertensive post-menopausal women.
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Aliskiren and l-arginine treatments restore depressed baroreflex sensitivity and decrease oxidative stress in renovascular hypertension rats. Hypertens Res 2016; 39:769-776. [PMID: 27383506 DOI: 10.1038/hr.2016.61] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 04/18/2016] [Accepted: 05/11/2016] [Indexed: 02/07/2023]
Abstract
Renovascular hypertension is characterized by increased angiotensin II and oxidative stress, and by endothelial dysfunction. The purpose of this study was to test whether the administration of aliskiren (ALSK) and l-arginine (l-ARG) would restore impaired baroreflex sensitivity and reduce oxidative stress in a rat renovascular hypertension model. Hypertension was induced by clipping the left renal artery, and the following five groups were created: SHAM; two-kidney, 1-clip (2K1C); 2K1C plus ALSK (ALSK); 2K1C plus l-ARG (l-ARG); and 2K1C plus ALSK+l-ARG (ALSK+l-ARG). After 21 days of treatment, only the ALSK+l-ARG group was effective in normalizing the arterial pressure (108.8±2.8 mm Hg). The l-ARG and ALSK+l-ARG groups did not show hypertrophy of the left ventricle. All the treatments restored the depressed baroreflex sensitivity to values found in the SHAM group. Acute administration of TEMPOL restored the depressed baroreflex sensitivity in the 2K1C group to values that resembled those presented by the other groups. All treatments were effective for an increase in the antioxidant pathway and reduction in the oxidative pathway. In conclusion, the treatment with ALSK or l-ARG reduced oxidative stress and restored reduced baroreflex sensitivity in renovascular hypertension. In addition, the treatments were able to normalize blood pressure and reverse left ventricular hypertrophy when used in combination.
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Hormone therapy with tamoxifen reduces plasma levels of NT-B-type natriuretic peptide but does not change ventricular ejection fraction after chemotherapy in women with breast cancer. ACTA ACUST UNITED AC 2014; 48:154-60. [PMID: 25424369 PMCID: PMC4321221 DOI: 10.1590/1414-431x20144189] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2014] [Accepted: 09/17/2014] [Indexed: 12/16/2022]
Abstract
The objective of this study was to evaluate the effect of tamoxifen on the plasma
concentration of NT-pro-B-type natriuretic peptide (NT-proBNP) in women undergoing
chemotherapy for breast cancer and to correlate changes in NT-proBNP with the left
ventricular ejection fraction (LVEF). Over a period of 12 months, we followed 60
women with a diagnosis of breast cancer. The patients were separated into a group
that received only chemotherapy (n=23), a group that received chemotherapy +
tamoxifen (n=21), and a group that received only tamoxifen (n=16). Plasma levels of
NT-proBNP were assessed at 0 (T0), 6 (T6), and 12 (T12) months of treatment, and
echocardiography data were assessed at T0 and T12. Plasma NT-proBNP levels were
increased in the chemotherapy-only group at T6 and T12, whereas elevated NT-proBNP
levels were only found at T6 in the chemotherapy + tamoxifen group. At T12, the
chemotherapy + tamoxifen group exhibited a significant reduction in the peptide to
levels similar to the group that received tamoxifen alone. The chemotherapy-only
group exhibited a significant decrease in LVEF at T12, whereas the chemotherapy +
tamoxifen and tamoxifen-only groups maintained levels similar to those at the
beginning of treatment. Treatment with tamoxifen for 6 months after chemotherapy
significantly reduced the plasma levels of NT-proBNP and did not change LVEF in women
with breast cancer.
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Combined aliskiren and L-arginine treatment has antihypertensive effects and prevents vascular endothelial dysfunction in a model of renovascular hypertension. ACTA ACUST UNITED AC 2014; 48:65-76. [PMID: 25493385 PMCID: PMC4288495 DOI: 10.1590/1414-431x20144191] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 09/09/2014] [Indexed: 02/07/2023]
Abstract
Angiotensin II is a key player in the pathogenesis of renovascular hypertension, a
condition associated with endothelial dysfunction. We investigated aliskiren (ALSK)
and L-arginine treatment both alone and in combination on blood pressure (BP), and
vascular reactivity in aortic rings. Hypertension was induced in 40 male Wistar rats
by clipping the left renal artery. Animals were divided into Sham, 2-kidney, 1-clip
(2K1C) hypertension, 2K1C+ALSK (ALSK), 2K1C+L-arginine (L-arg), and
2K1C+ALSK+L-arginine (ALSK+L-arg) treatment groups. For 4 weeks, BP was monitored and
endothelium-dependent and independent vasoconstriction and relaxation were assessed
in aortic rings. ALSK+L-arg reduced BP and the contractile response to phenylephrine
and improved acetylcholine relaxation. Endothelium removal and incubation with
N-nitro-L-arginine methyl ester (L-NAME) increased the response to phenylephrine in
all groups, but the effect was greater in the ALSK+L-arg group. Losartan reduced the
contractile response in all groups, apocynin reduced the contractile response in the
2K1C, ALSK and ALSK+L-arg groups, and incubation with superoxide dismutase reduced
the phenylephrine response in the 2K1C and ALSK groups. eNOS expression increased in
the 2K1C and L-arg groups, and iNOS was increased significantly only in the 2K1C
group compared with other groups. AT1 expression increased in the 2K1C
compared with the Sham, ALSK and ALSK+L-arg groups, AT2 expression
increased in the ALSK+L-arg group compared with the Sham and L-arg groups, and
gp91phox decreased in the ALSK+L-arg group compared with the 2K1C and ALSK groups. In
conclusion, combined ALSK+L-arg was effective in reducing BP and preventing
endothelial dysfunction in aortic rings of 2K1C hypertensive rats. The responsible
mechanisms appear to be related to the modulation of the local renin-angiotensin
system, which is associated with a reduction in endothelial oxidative stress.
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Relationship of inflammatory markers and pain in patients with head and neck cancer prior to anticancer therapy. ACTA ACUST UNITED AC 2014; 47:600-4. [PMID: 25003634 PMCID: PMC4123840 DOI: 10.1590/1414-431x20143599] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Accepted: 03/12/2014] [Indexed: 12/29/2022]
Abstract
Pain is a common symptom in patients with cancer, including those with head and neck cancer (HNC). While studies suggest an association between chronic inflammation and pain, levels of inflammatory cytokines, such as C-reactive protein (CRP) and tumor necrosis factor-alpha (TNF-α), have not been correlated with pain in HNC patients who are not currently undergoing anticancer treatment. The purpose of this study was to examine the relationship between these inflammatory markers and perceived pain in HNC patients prior to anticancer therapy. The study group consisted of 127 HNC patients and 9 healthy controls. Pain was assessed using the Brief Pain Inventory (BPI), and serum levels of CRP and TNF-α were determined using the particle-enhanced turbidimetric immunoassay (PETIA) and ELISA techniques, respectively. Patients experiencing pain had significantly higher levels of CRP (P<0.01) and TNF-α (P<0.05) compared with controls and with patients reporting no pain. There were significantly positive associations between pain, CRP level, and tumor stage. This is the first study to report a positive association between perceived pain and CRP in HNC patients at the time of diagnosis. The current findings suggest important associations between pain and inflammatory processes in HNC patients, with potential implications for future treatment strategies.
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Influence of pain severity on the quality of life in patients with head and neck cancer before antineoplastic therapy. BMC Cancer 2014; 14:39. [PMID: 24460780 PMCID: PMC3904211 DOI: 10.1186/1471-2407-14-39] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 12/20/2013] [Indexed: 12/21/2022] Open
Abstract
Background The aim of this study was to assess the severity of pain and its impact on the quality of life (QoL) in untreated patients with head and neck squamous cell carcinoma (HNSCC). Methods A study group of 127 patients with HNSCC were interviewed before antineoplastic treatment. The severity of pain was measured using the Brief Pain Inventory (BPI) questionnaire, and the QoL was assessed with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core-30 (EORTC QLQ-C30) and the head and neck module (QLQ-H&N35). Results The mean age of the patients was 57.9 years, and there was a predominance of men (87.4%). The most frequent site of the primary tumor was the oral cavity (70.6%), and the majority of the patients had advanced cancers (stages III and IV). QoL in early stage of cancer obtained better scores. Conversely, the patients with advanced stage cancer scored significantly higher on the symptom scales regarding fatigue, pain, appetite loss and financial difficulties, indicating greater difficulties. Regard to the severity of pain, patients with moderate-severe pain revealed a significantly worse score than patients without pain. Conclusions The severity of pain is statistically related to the advanced stages of cancer and directly affects the QoL. An assessment of the quality of life and symptoms before therapy can direct attention to the most important symptoms, and appropriate interventions can then be directed toward improving QoL outcomes and the response to treatment.
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Sertraline inhibits formalin-induced nociception and cardiovascular responses. Braz J Med Biol Res 2011; 45:43-8. [PMID: 22086464 PMCID: PMC3854144 DOI: 10.1590/s0100-879x2011007500154] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2011] [Accepted: 10/31/2011] [Indexed: 12/22/2022] Open
Abstract
The objective of the present study was to determine the antihyperalgesic effect of sertraline, measured indirectly by the changes of sciatic afferent nerve activity, and its effects on cardiorespiratory parameters, using the model of formalin-induced inflammatory nociception in anesthetized rats. Serum serotonin (5-HT) levels were measured in order to test their correlation with the analgesic effect. Male Wistar rats (250-300 g) were divided into 4 groups (N = 8/per group): sertraline-treated group (Sert + Saline (Sal) and Sert + Formalin (Form); 3 mg·kg-1·day-1, ip, for 7 days) and saline-treated group (Sal + Sal and Sal + Form). The rats were injected with 5% (50 µL) formalin or saline into the right hind paw. Sciatic nerve activity was recorded using a silver electrode connected to a NeuroLog apparatus, and cardiopulmonary parameters (mean arterial pressure, heart rate and respiratory frequency), assessed after arterial cannulation and tracheotomy, were monitored using a Data Acquisition System. Blood samples were collected from the animals and serum 5-HT levels were determined by ELISA. Formalin injection induced the following changes: sciatic afferent nerve activity (+50.8 ± 14.7%), mean arterial pressure (+1.4 ± 3 mmHg), heart rate (+13 ± 6.8 bpm), respiratory frequency (+4.6 ± 5 cpm) and serum 5-HT increased to 1162 ± 124.6 ng/mL. Treatment with sertraline significantly reduced all these parameters (respectively: +19.8 ± 6.9%, -3.3 ± 2 mmHg, -13.1 ± 10.8 bpm, -9.8 ± 5.7 cpm) and serum 5-HT level dropped to 634 ± 69 ng/mL (P < 0.05). These results suggest that sertraline plays an analgesic role in formalin-induced nociception probably through a serotonergic mechanism.
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Involvement of the atrial natriuretic peptide in the reduction of arterial pressure induced by swimming but not by running training in hypertensive rats. Peptides 2011; 32:1706-12. [PMID: 21762739 DOI: 10.1016/j.peptides.2011.06.027] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/14/2011] [Revised: 06/28/2011] [Accepted: 06/28/2011] [Indexed: 11/23/2022]
Abstract
The aim of this study was to compare, under resting conditions, the influence of chronic training in swimming or running on mean arterial pressure (MAP) and the involvement of the natriuretic peptide system in this response. Two-month-old male spontaneously hypertensive rats (SHR) were divided into three groups-sedentary (SD), swimming (SW) and running (RN)-and were trained for eight weeks under regimens of similar intensities. Atria tissue and plasma atrial natriuretic peptide (ANP) concentrations were measured by radioimmunoassay. ANP mRNA levels in the right and left atria as well as the natriuretic peptide receptors (NPR), NPR-A and NPR-C, mRNA levels in the kidney were determined by real-time PCR. Autoradiography was used to quantify NPR-A and NPR-C in mesenteric adipose tissue. Both training modalities, swimming and running, reduced the mean arterial pressure (MAP) of SHR. Swimming, but not running, training increased plasma levels of ANP compared to the sedentary group (P<0.05). Expression of ANP mRNA in the left atrium was reduced in the RN compared to the SD group (P<0.05). Expression of NPR-A and NPR-C in the kidneys of the SW group decreased significantly (P<0.05) compared to the SD group. Although swimming increased (125)I-ANP binding to mesenteric adipose tissue, displacement by c-ANF was reduced, indicating a reduction of NPR-C. These results suggest that the MAP reduction induced by exercise in SHR differs in its mechanisms between the training modalities, as evidenced by the finding that increased levels of ANP were only observed after the swimming regimen.
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Activity of angiotensin-converting enzyme after treatment with L-arginine in renovascular hypertension. Clin Exp Hypertens 2005; 26:569-79. [PMID: 15554459 DOI: 10.1081/ceh-200031837] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The renin-angiotensin system plays a role in the pathophysiology of renovascular hypertension. In addition, some studies have demonstrated a beneficial effect of L-arginine (L-Arg), the precursor of nitric oxide (NO), in this model of hypertension. This study was designed to investigate the effects of L-Arg on cardiovascular parameters and on the activity of the angiotensin-converting enzyme (ACE), after 14 days of renovascular hypertension. The experiments were performed on conscious male Wistar rats. Two-kidney, one-clip renovascular hypertension (2KIC) was initiated in rats by clipping the left renal artery during 14 days, while control rats were sham-operated. One group was submitted to a similar procedure and treated with L-Arg (10 mg/ml; average intake of 300mg/day) from the 7th to the 14th day after surgery, whereas the respective control group received water instead. At the end of the treatment period, the mean arterial pressure (MAP) was measured in conscious animals. The rats were sacrificed and the ACE activity was assayed in heart and kidneys, using Hip-His-Leu as substrate. In a separate group, the heart was removed, the left ventricle (LV) was weighed and the LV/body weight ratios (LV/BW) were determined. We observed significant differences in MAP between the L-Arg-treated and untreated groups (129 +/- 7 vs. 168 +/- 6 mmHg; P< 0.01). The cardiac hypertrophy described for this model of hypertension was attenuated in the 2K1C-L-Arg-treated group (14th day, wet LV/BW: 2K1C-L-Arg = 1.88 +/- 0.1; 2K1C = 2.20 +/- 0.1 mg/g; P < 0.05). L-Arg administration caused an important decrease in cardiac ACE activity (2K1C-L-Arg: 118 +/- 15; 2K1C: 266 +/- 34 micromol/min/mg; P < 0.01). L-Arg also decreased the ACE activity in the clipped kidney by 47% (P < 0.01), but not in the nonclipped kidney. These data suggest that increased NO formation and reduced angiotensin II formation are involved in the anthihypertensive effect of orally administered L-arginine.
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Activity of angiotensin-converting enzyme after treatment with L-arginine in renovascular hypertension. CLINICAL AND EXPERIMENTAL HYPERTENSION (NEW YORK, N.Y. : 1993) 2005. [PMID: 15554459 DOI: 10.1081/ceh-200031837.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The renin-angiotensin system plays a role in the pathophysiology of renovascular hypertension. In addition, some studies have demonstrated a beneficial effect of L-arginine (L-Arg), the precursor of nitric oxide (NO), in this model of hypertension. This study was designed to investigate the effects of L-Arg on cardiovascular parameters and on the activity of the angiotensin-converting enzyme (ACE), after 14 days of renovascular hypertension. The experiments were performed on conscious male Wistar rats. Two-kidney, one-clip renovascular hypertension (2KIC) was initiated in rats by clipping the left renal artery during 14 days, while control rats were sham-operated. One group was submitted to a similar procedure and treated with L-Arg (10 mg/ml; average intake of 300mg/day) from the 7th to the 14th day after surgery, whereas the respective control group received water instead. At the end of the treatment period, the mean arterial pressure (MAP) was measured in conscious animals. The rats were sacrificed and the ACE activity was assayed in heart and kidneys, using Hip-His-Leu as substrate. In a separate group, the heart was removed, the left ventricle (LV) was weighed and the LV/body weight ratios (LV/BW) were determined. We observed significant differences in MAP between the L-Arg-treated and untreated groups (129 +/- 7 vs. 168 +/- 6 mmHg; P< 0.01). The cardiac hypertrophy described for this model of hypertension was attenuated in the 2K1C-L-Arg-treated group (14th day, wet LV/BW: 2K1C-L-Arg = 1.88 +/- 0.1; 2K1C = 2.20 +/- 0.1 mg/g; P < 0.05). L-Arg administration caused an important decrease in cardiac ACE activity (2K1C-L-Arg: 118 +/- 15; 2K1C: 266 +/- 34 micromol/min/mg; P < 0.01). L-Arg also decreased the ACE activity in the clipped kidney by 47% (P < 0.01), but not in the nonclipped kidney. These data suggest that increased NO formation and reduced angiotensin II formation are involved in the anthihypertensive effect of orally administered L-arginine.
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