Clinical, histomorphological and therapeutic features of the Van der Woude Syndrome: literature review and presentation of an unusual case

BACKGROUND

Van der Woude syndrome (VWS), an autosomal dominant condition associated with lower lip pits and/or cleft palate, is caused by mutations in the interferon regulatory factor 6 gene (lRF6 gene). The genetic alterations identified to date that contribute to expression of the syndrome are chiefly mutations located on chromosome 1 (the largest of our chromosomes), mutations at p36 that codifies the gene GRHL (grainy-head transcriptor factor) and mutations involving IRF6 (interferon regulatory factor). With frequency ranging from 1:35,000 to 1:100,000, depending on ethnicity, gender, and socio-economic status, the syndrome accounts for about 2% of orofacial clefts. The clinical and histomorphological aspects of VWS are studied, and a case of heterozygous female twins of whom only one was affected with VWS is reported.

CONCLUSION

This very rare case (no similar case has been reported to date) contributes further evidence on modifying factors in the expression of this condition.

Cardiotoxicity during Chemotherapy for Advanced Gastroenteric Tumors

The authors report two cases of patients with advanced gastroenteric carcinoma, which developed different cardiotoxicity patterns after the administration of cytotoxic drugs. The firsts patient showed a picture of dilatative cardiomyopathy with associated symptoms of angina pectoris and congestive heart failure; the second patient presented a cardiac arrhythmia after several administrations of S-fluorouracil. The possible mechanisms of these toxic effects, as well as the drug interactions are briefly discussed. Cardiotoxicity of cytotoxic drugs should be considered by oncologists even in patients with no previous history of cardiac disease.

Tongue-tie assessment: clinical aspects and a new diode laser technique for its management

BACKGROUND Often breastfeeding problems experienced by mothers and their babies may be attributed to the abnormal attachment of the infant's tongue (ankyloglossia) and/or maxillary lip-tie. Proper breastfeeding depends upon an infant's ability to correctly latch onto its mother's breast. If born with oral soft tissue abnormalities such as tongue-tie or lip-tie, it may be almost impossible for the infant to breastfeed. During the oral evaluation of an infant presenting with breastfeeding problems, one factor that is often overlooked and undiagnosed - and thus untreated - is the attachment of the upper lip to the maxillary gingival tissue.

CASE REPORT

The case is reported of tongue-tie and breastfeeding difficulties, treated with a novel technique: the diode laser (980 nm).

Mucocele of the minor salivary glands in an infant: treatment with diode laser

BACKGROUND

Mucoceles are benign lesions that develop as a result of retention or extravasation of mucous material from minor salivary glands. Very uncommon in newborns and infants, they rarely may interfere with breastfeeding and compromise the respiratory function.

CASE REPORT

We report a case of mucocele in a three-month-old infant in the right labial commissure excised by diode laser of different wavelengths (635-980 nm), with an average power of 1.8 W, in continuous wave mode, using 300 to 320 micron optical fibers. The healing occurred in 10 days. There were no adverse effects and the patient was carefully followed-up until complete healing.

CONCLUSION

T he diode laser is not only a valuable tool for mucocele eradication but it also reduces relapses, thanks to the characteristics of the laser light.

Salivary α-amylase and cortisol after exercise in menopause: influence of long-term HRT

OBJECTIVES

This observational prospective study analyzed the effect of an incremental cardiopulmonary exercise test (CPET) on the secretion of salivary biomarkers of the adrenergic nervous system and hypothalamus-pituitary-adrenal (HPA) axis activity by measuring salivary α-amylase and cortisol diurnal trajectories in the setting of long-term hormone replacement therapy (HRT).

METHODS

Fifteen healthy sedentary postmenopausal women who were current HRT users and 15 women who had never used HRT were consecutively recruited. α-Amylase and cortisol were measured in salivary samples collected on the CPET day and on a rest day. Cardiovascular and respiratory fitness parameters were recorded during the CPET challenge.

RESULTS

The participants had very homogeneous somatic characteristics, and they were all in generally good health. The postmenopausal never-HRT users presented an abnormal diurnal pattern of α-amylase at baseline and a flattened response to CPET. In contrast, women on HRT had a physiological α-amylase diurnal pattern and increased salivary α-amylase production during the CPET-induced challenge. The CPET challenge physiologically activated the HPA axis activity, as shown by the increase in the concentration of salivary cortisol during the effort test. HPA axis activity was not affected by long-term HRT. Postmenopausal women using HRT exhibited a cardiorespiratory functional capacity that was significantly (p < 0.05) higher than that of non-users.

CONCLUSIONS

Our findings show that healthy postmenopausal women present an asymmetry between adrenergic nervous system and HPA axis activities under both basal and stress conditions. HRT was able to modify the abnormal adrenergic nervous system activity, most likely by reducing the sympathetic hyperactivity that characterizes menopause.

Interaction between catechol-O-methyltransferase (COMT) Val158Met genotype and genetic vulnerability to schizophrenia during explicit processing of aversive facial stimuli

BACKGROUND

Emotion dysregulation is a key feature of schizophrenia, a brain disorder strongly associated with genetic risk and aberrant dopamine signalling. Dopamine is inactivated by catechol-O-methyltransferase (COMT), whose gene contains a functional polymorphism (COMT Val158Met) associated with differential activity of the enzyme and with brain physiology of emotion processing. The aim of the present study was to investigate whether genetic risk for schizophrenia and COMT Val158Met genotype interact on brain activity during implicit and explicit emotion processing.

METHOD

A total of 25 patients with schizophrenia, 23 healthy siblings of patients and 24 comparison subjects genotyped for COMT Val158Met underwent functional magnetic resonance imaging during implicit and explicit processing of facial stimuli with negative emotional valence.

RESULTS

We found a main effect of diagnosis in the right amygdala, with decreased activity in patients and siblings compared with control subjects. Furthermore, a genotype × diagnosis interaction was found in the left middle frontal gyrus, such that the effect of genetic risk for schizophrenia was evident in the context of the Val/Val genotype only, i.e. the phenotype of reduced activity was present especially in Val/Val patients and siblings. Finally, a complete inversion of the COMT effect between patients and healthy subjects was found in the left striatum during explicit processing.

CONCLUSIONS

Overall, these results suggest complex interactions between genetically determined dopamine signalling and risk for schizophrenia on brain activity in the prefrontal cortex during emotion processing. On the other hand, the effects in the striatum may represent state-related epiphenomena of the disorder itself.

Quantitative analysis of elastography images in the detection of breast cancer

PURPOSE

The aim of this study was to develop a quantitative method for breast cancer diagnosis based on elastosonography images in order to reduce whenever possible unnecessary biopsies. The proposed method was validated by correlating the results of quantitative analysis with the diagnosis assessed by histopathologic exam.

MATERIAL AND METHODS

109 images of breast lesions (50 benign and 59 malignant) were acquired with the traditional B-mode technique and with elastographic modality. Images in Digital Imaging and COmmunications in Medicine format (DICOM) were exported into a software, written in Visual Basic, especially developed to perform this study. The lesion was contoured and the mean grey value and softness inside the region of interest (ROI) were calculated. The correlations between variables were investigated and receiver operating characteristic (ROC) curve analysis was performed to assess the diagnostic accuracy of the proposed method. Pathologic results were used as standard reference.

RESULTS

Both the mean grey value and the softness inside the ROI resulted statistically different at the t test for the two populations of lesions (i.e., benign versus malignant): p<0.0001. The area under the curve (AUC) was 0.924 (0.834-0.973) and 0.917 (0.826-0.970) for the mean grey value and for the softness respectively.

CONCLUSIONS

Quantitative elastosonography is a promising ultrasound technique in the detection of breast cancer but large prospective trials are necessary to determine whether quantitative analysis of images can help to overcome some pitfalls of the methodic.

Combined hyperlipidaemia as a presenting sign of cholesteryl ester storage disease

Lysosomal acid lipase (LAL) deficiency results in Wolman disease and cholesteryl ester storage disease (CESD), a more benign form. CESD is a recessive disorder characterized by hypercholesterolaemia, hypertriglyceridaemia, low blood HDL and variable phenotype, while hepatomegaly is usually evident during childhood or adolescence. An 11-year-old girl was referred to our department for combined hyperlipidaemia (total cholesterol 323, triglycerides 259 mg/dl). All family members had normal lipid profile and liver function tests. At 8 years she was admitted for acute Epstein-Barr virus infection, with hepatosplenomegaly and elevation of liver enzymes. Liver-spleen enlargement resolved, but serum alanine aminotransferase and aspartate aminotransferase were persistently twice the upper limits, with other liver function tests within the normal range. Ultrasonography showed normal liver and spleen size and minimal hepatic steatosis. Infectious, autoimmune and metabolic causes of elevated liver enzymes were ruled out, including glycogen storage disease. Dysbetalipoproteinaemia was also ruled out (ApoE phenotype: E3E3). In the following 2 years the girl was symptom-free, BMI was at the 50th-75th centile for age and lipid profile was unchanged despite a low-fat diet. At 13 years of age, low acid lipase activity was demonstrated in leukocytes (10 nmol/h/ per mg protein, normal 140-380) and cultured skin fibroblasts (181 nmol/h per mg protein, normal 1100-2400), leading to diagnosis of CESD. CESD usually progresses to hepatic fibrosis, with high risk of premature atherosclerosis. CESD prevalence may be underestimated in the general population. The diagnosis may be considered in all subjects with atypical combined hyperlipidaemia (usually dominant in transmission or related to metabolic syndrome) and atypical 'fatty liver disease', in the absence of overweight.

Long term effects of bosentan treatment in adult patients with pulmonary arterial hypertension related to congenital heart disease (Eisenmenger physiology): safety, tolerability, clinical, and haemodynamic effect

BACKGROUND

Oral bosentan is an established treatment for pulmonary arterial hypertension (PAH).

OBJECTIVE

To evaluate safety, tolerability, and clinical and haemodynamic effects of bosentan in patients with PAH related to congenital heart disease (CHD).

PATIENTS

22 patients with CHD related PAH (8 men, 14 women, mean (SD) age 38 (10) years) were treated with oral bosentan (62.5 mg x 2/day for the first 4 weeks and then 125 mg x 2/day).

MAIN OUTCOME MEASURES

Clinical status, liver enzymes, World Health Organisation (WHO) functional class, resting oxygen saturations and 6-min walk test (6MWT) were assessed at baseline and at 1, 3, 6, and 12 months. Haemodynamic evaluation with cardiac catheterisation was performed at baseline and at 12 month follow-up.

RESULTS

12 patients had ventricular septal defect, 5 atrioventricular canal, 4 single ventricle, and 1 atrial septal defect. All patients tolerated bosentan well. No major side effects were seen. After a year of treatment, an improvement was seen in WHO functional class (2.5 (0.7) v 3.1 (0.7); p<0.05), oxygen saturation at rest (87 (6%) v 81 (9); p<0.001), heart rate at rest (81 (10) v 87 (14) bpm; p<0.05), distance travelled in the 6MWT (394 (73) v 320 (108) m; p<0.001), oxygen saturation at the end of the 6MWT (71 (14) v 63 (17%); p<0.05), Borg index (5.3 (1.8) v 6.5 (1.3); p<0.001), pulmonary vascular resistances index (14 (9) v 22 (12) WU m(2); p<0.001), systemic vascular resistances index (23 (11) v 27 (10) WU.m(2); p<0.01), pulmonary vascular resistances index/systemic vascular resistances index (0.6 (0.5) v 0.9 (0.6); p<0.05); pulmonary (4.0 (1.3) v 2.8 (0.9) l/min/m2; p<0.001) and systemic cardiac output (4.2 (1.4) v 3.4 (1.1) l/min/m2; p<0.05).

CONCLUSIONS

Bosentan was safe and well tolerated in adults with CHD related PAH during 12 months of treatment. Clinical status, exercise tolerance, and pulmonary haemodynamics improved considerably.

Influenza vaccination in patients on long-term anticoagulant therapy

The study evaluates the risk/benefit of influenza vaccination in patients on stable long-term oral anticoagulant therapy (OAT). One hundred and four consecutive patients with indication for influenza vaccination were randomized to receive one dose of 2004/2005 influenza vaccine followed by placebo after 6 weeks, or vice versa, in a cross-over blinded trial. All patients were tested for anticoagulation levels and for hemagglutination inhibiting antibody titres against the influenza vaccine antigens. The highly protective antibody titres induced by influenza vaccination and the absence of statistically relevant interactions between vaccination and OAT suggest that influenza vaccination can be used safely and successfully in elderly patients on OAT.

Safety and Efficacy of Ximelagatran: Meta-Analysis of the Controlled Randomized Trials for the Prophylaxis or Treatment of Venous Thromboembolism

BACKGROUND

Ximelagatran has been approved in Europe for VTE prophylaxis in orthopedic surgery at fixed doses and without laboratory monitoring. Aim of the study was to evaluate safety and efficacy of ximelagatran in a meta-analysis of prophylaxis and/or treatment randomized controlled trials.

METHODS

Absolute risk of events for ximelagatran and OR for its comparison with LMWH and coumarins were calculated. Subgroup analysis was performed for ximelagatran regimen, comparator agent, type of surgery, starting time of prophylaxis.

RESULTS

Twelve studies and 16,992 patients were meta-analysed. Ximelagatran showed an absolute risk of major VTE of 4.04% and 1.69% and of major bleedings of 1.68% and 1.03% in prophylaxis and treatment trials, respectively. In prophylaxis trials, a significant excess mortality (OR: 2.5; 95% CI: 1.02 - 6.13) and an excess in major bleedings (OR: 1.41; 95% CI: 0.93 - 2.14) was found in the whole ximelagatran group. No evidence of treatment effect for major VTE was seen in the comparison with LMWH (OR: 1.01; 95% CI: 0.52 - 1.97). The cohort of patients treated with 24 mg b.i.d. showed similar results. An increase in the absolute risk of bleeding (from 1.04% to 3.03%) was found between post and preoperative administration of ximelagatran. Major VTE risk was increased when ximelagatran was compared to b.i.d. LMWH.

CONCLUSIONS

Ximelagatran can be considered for its potential advantages for prevention and treatment of VTE. Future efforts are needed by researchers to prospectively investigate the best postoperatively starting time and by clinicians to monitor overall mortality in prophylactic use.

Sildenafil increases cerebrovascular reactivity: A transcranial Doppler study

The authors performed a double-blind, placebo-controlled study in 28 patients to evaluate the effects of sildenafil on cerebral hemodynamics. A significant improvement of cerebrovascular reactivity, without any modification of other variables, was recorded 1 hour after the administration of 50 mg sildenafil. Further investigations are needed to evaluate whether cerebrovascular reactivity improvement could contribute to triggering sildenafil-induced migraine.

CagA-positive Helicobacter pylori strains may influence the natural history of atherosclerotic stroke

OBJECTIVE

To test the hypothesis that infection with virulent cytotoxin-associated gene-A (CagA)-bearing Helicobacter pylori strains influences the atherosclerotic process and the clinical course in atherosclerotic stroke patients.

METHODS

ELISA was used to assess the seroprevalence of infection by H. pylori and CagA-positive strains in 185 patients. Intima-media thickness (IMT) was determined by Doppler ultrasound. Baseline, 1-week, and 1-month NIH Stroke Scale (NIHSS) scores were used to evaluate the short-term clinical course.

RESULTS

H. pylori infection was found in 79% of patients; 58% of these tested positive for CagA. IMT was higher among CagA-positive patients than among CagA-negative ones (1.13 +/- 0.26 mm vs 0.97 +/- 0.15 mm; univariate analysis, p = 0.0001; multivariate analysis, odds ratio [OR], 2.36; 95% CI, 1.57 to 3.54; p = 0.0001) or H. pylori-negative ones (1.01 +/- 0.17 mm; univariate analysis, p = 0.007; multivariate analysis, OR, 1.90; 95% CI, 1.22 to 2.97; p = 0.005). CagA-positive patients had poorer initial outcomes based on serial measurements of the NIHSS score (repeated measures analysis of variance, p < 0.0001). No significant difference in IMT and NIHSS score was found between H. pylori-positive and H. pylori-negative patients.

CONCLUSIONS

Infection with cytotoxin-associated gene-A-positive Helicobacter pylori strains in atherosclerotic stroke patients is associated with greater intima-media thickness and poorer short-term outcome compared with cytotoxin-associated gene-A-negative patients.

Fragmentations and reactions of the organophosphate insecticide Diazinon and its oxygen analog Diazoxon studied by electrospray ionization ion trap mass spectrometry

The fragmentations and reactions of Diazinon and related compounds have been studied by electrospray ionization ion trap mass spectrometry. Several novel fragmentation and rearrangements have been observed, including an intramolecular thiono-thiolo rearrangement. The stability, in the gas-phase, of the protomers of 2-isopropyl-4-methyl-6-pyrimidinol has been demonstrated. The complexity of the gas phase ion processes observed suggest that, at present, caution should be exercised in using this approach for the analysis of environmental and other samples until our understanding of these processes increases considerably.

Phyto-oestrogens in the prophylaxis of menstrual migraine

BACKGROUND

Falling levels of estrogen is the major provocative factor in migraine associated with menstruation.

OBJECTIVE

We assessed the efficacy of the combination of two phyto-oestrogens, as perimenstrual, prophylactic treatment of menstrual migraine and tested their effect on cerebral haemodynamic.

SUBJECTS AND METHODS

Women with a history of menstrual migraine (i.e., attacks occurring exclusively on day 1+/-2 days of menstruation and at no other time of the cycle) were included in the study. Eleven women fulfilling the inclusion criteria underwent to a 3-month cyclic treatment with 56 mg of genisteine and 20 mg of diadzeine per day. Transcranial doppler evaluation (TCD) was performed at baseline and after treatment.

RESULTS

Among the ten women who completed the study the average number of days with migraine during the baseline period decreased significantly after 3 months of therapy (P < 0.005). There were no major side-effects. Therapy did not affect cerebral blood flow velocities.

CONCLUSIONS

Phyto-oestrogens appear to be an effective treatment in menstrual migraine prophylaxis. This effect seems to be unrelated to cerebral hemodynamic. Placebo-controlled trials on larger number of patients are necessary to confirm our findings.

Hernia repair in the Lombardy region in 2000: Preliminary results

Hernia repair is the most common surgical procedure in general surgery in Italy and in the Lombardy region. In the last decade, the use of mesh, the concept of a tension-free technique, and the postoperative rate of recurrences after Bassini or Shouldice operations have completely changed the surgical approach to hernia repair. For this reason, we sent a questionnaire to 148 surgical departments in the Lombardy region to investigate about total hernia operations performed in 2000 in Lombardy, the surgical approach, the surgical techniques used, the type of anesthesia and the hospital stay. One hundred five out of 148 surgical departments returned the questionnaire, and we collected information on a total of 16,935 surgical operations for hernia: 16,494 were performed using tension-free techniques. The inguinal anterior approach is the one of choice for primary and recurrent inguinal hernia, whereas the open preperitoneal and laparoscopic approaches are limited to bilateral and recurrent hernias. The majority of cases were treated under locoregional anesthesia and with a hospital stay of two nights.

Carotid artery intima-media thickness and lacunar versus nonlacunar infarcts

BACKGROUND AND PURPOSE

Increases in the thickness of the intima and media of the carotid artery have been associated with an increased risk of myocardial infarction and stroke in subjects without a history of cardiovascular disease. Lacunar infarcts, one of the most common subtype of ischemic stroke, show unique pathological and clinicoradiological characteristics. The present study examines the relationship between vascular risk factors, including carotid artery intima-media thickness (IMT), and lacunar versus nonlacunar infarcts.

METHODS

We collected data from patients with acute ischemic stroke admitted to hospital. Patients and 129 control subjects underwent B-mode ultrasonographic measurements of IMT of the common carotid artery. We examined the association of lacunar and nonlacunar infarcts with age, sex, and potential vascular risk factors.

RESULTS

Of 292 adult patients with an acute first-ever ischemic stroke, 96 were considered lacunar and 196 were considered nonlacunar strokes. We did not find a significantly different percentage of diabetes, smoking, hypertension, dyslipidemia, myocardial infarction, and previous transient ischemic attack between the 2 groups of patients. The multinomial logistic regression procedure selected carotid artery IMT and atrial fibrillation as the only independent factors able to discriminate between lacunar and nonlacunar patients. IMT values were significantly higher in patients with nonlacunar stroke versus both those with lacunar stroke and control subjects.

CONCLUSIONS

The present results indicate the usefulness of noninvasive measurement of IMT with ultrasonic techniques as a diagnostic tool that may help to identify different subtypes of ischemic stroke patients. The noninvasive measurements may have predictive power with respect to lacunar versus nonlacunar infarcts.

[Small bowel diverticula in adults: clinical and therapeutic features. Report of 2 cases and review of the literature]

The true diverticula of the small bowell are a very rare observation in clinical practice; they have a malformative origin and, occasionally, are acquired, contrary to what observed in the colon, where they are frequently an acquired pathology. They can involve the small bowel as a single lesion (Meckel's diverticulum), or as a segmentary disease (duodenal diverticula), or as a diffused diverticulosis. Generally they are asymptomatic and rarely they produce a true pathology. The symptomatic disease is primarily found in pediatric age and it requires a surgical procedure. This makes even more rare the diverticular pathology in the adult. The authors report 1 case of intestinal occlusion due to ileoileo-colic invagination arising from a Meckel's diverticulum and 1 case of intestinal occlusion in presence of a severe and acute diffuse diverticulosis of the small bowell, both in adult patients.

[Late post-traumatic diaphragmatic hernia: unusual cause of colonic occlusion]

Traumatic diaphragmatic rupture is not an uncommon problem, particularly in the last few years because of the increasing number of road accidents, improved diagnostic techniques and resuscitation techniques after serious traumas. In a certain number of cases, post-traumatic diaphragmatic hernias may become clinically manifest only months or years after thoracic or abdominal trauma and are still a challenge to surgeons because of the vague clinical symptoms and the diagnostic difficulties involved. The Authors report a case of acute colon occlusion due to diaphragmatic hernia 24 months after thoraco-abdominal trauma. None of the radiological or endoscopic examinations demonstrated the presence of diaphragmatic hernia. Laparoscopy showed a diaphragmatic rupture with incarceration of the left colonic segment. The laparoscopic procedure was converted for technical reasons and the diaphragmatic defect was closed with a primary suture.

Influence of physiologic oscillation of estrogens on cerebral hemodynamics

The interactions between estrogens and the cerebrovascular system are complex and not fully understood. There are evidences suggesting that the hormones confer protection against cerebral ischemia. Our aim in this study was to investigate the effects of physiological variations of estradiol plasmatic concentration on cerebral hemodynamics. We investigated cerebrovascular reactivity to hypercapnia with transcranial Doppler ultrasonography and the breath-holding index method in the right middle cerebral artery of 20 young women during the menstrual and the ovulatory phase. Data were compared with those of 20 men matched for age. The mean value of the breath-holding index was significantly higher (p<0.001) in females during the ovulatory phase than in the menstrual phase. In men, values were similar to those of women during the menstrual phase. These results suggest that estrogens influence the adaptation capacity of the cerebrovascular system. The possible pathophysiological implications of the relationships between sex hormones and cerebral hemodynamics deserve further investigation.

Ca2+ channels of the L-type in peripheral blood lymphocytes of essential hypertensives

Ca2+ channels of the L-type were assayed in human peripheral blood lymphocytes of normotensive control subjects and of essential hypertensives using radioligand binding assay techniques. The dihydropyridine Ca2+ channel blocker [3H](+)-PN 200-110 [isopropyll-4-(2,1,3-benzoxadiazol-4-yl)1,4-dihydro-5-methox ycarbonyl-2,6-dimethyl-3-pyridine carboxylate] was used as a ligand. [3H](+)-PN 200 110 was bound specifically to human peripheral blood lymphocytes in a manner consistent with the labeling of Ca2+ channels of the L-type. No significant differences in the dissociation constant (Kd), in the maximum density of binding sites (Bmax) or in the pharmacological profile of [3H](+)-PN 200 110 binding were found between normotensive subjects and different degree essential hypertensives. Analysis of the intralymphocytic free Ca2+ concentration did not reveal differences between normotensive subjects and essential hypertensives. Although hypertension is associated with altered membrane handling of Ca2+, no changes in the expression of peripheral blood lymphocyte Ca2+ channels of the L-type or in intralymphocytic Ca2+ concentrations were found in essential hypertensives. Human peripheral blood lymphocytes therefore cannot represent a peripheral marker of altered Ca2+ handling in hypertension.

Density and localization of calcium channels of the L-type in human pulmonary artery

The pharmacological profile and the anatomical localization of Ca2+ channels of the L-type were investigated in the human pulmonary artery to identify possible mechanisms involved in the regulation of the pulmonary vascular tone. Analysis was performed on slide-mounted frozen sections of human pulmonary artery using radioligand binding assay techniques associated with light microscope autoradiography. [3H]-Nicardipine was used as ligand. Human renal and right coronary arteries also were used as systemic reference arteries. Binding of [3H]-nicardipine to sections of human pulmonary artery was time-, temperature- and concentration-dependent, saturable and reversible. In the human pulmonary artery, the apparent equilibrium dissociation constant (Kd) was 0.12+/-0.02 nM and the maximum density of binding sites (Bmax) was 38.15+/-2.25 fmol/mg tissue. Kd values were 0.3+/-0.01 nM and 0.5+/-0.02 in the human renal artery and right coronary artery respectively. Bmax values were 248+/-16 fmol/mg tissue and 173+/-9.5 fmol/mg tissue in the human renal artery and right coronary artery respectively. The pharmacological profile of [3H]-nicardipine binding to sections of human pulmonary artery was consistent with the labeling of Ca2+ channels of the L-type. It was similar in the pulmonary artery and in the human renal and right coronary arteries. Light microscope autoradiography revealed a high density of [3H]-nicardipine binding sites within smooth muscle of the tunica media of human pulmonary artery as well as of human renal and right coronary arteries. A lower accumulation of the radioligand occurred in the tunica adventitia. No specific binding was noticeable in the tunica intima. Our data suggest that human pulmonary artery expresses Ca2+ channels of the L-type sensitive to dihydropyridines. These sites have similar affinity and lower density than those expressed by systemic arteries. The presence of Ca2+ channels of the L-type in human pulmonary artery suggests that their pharmacological manipulation may be considered in the treatment of pulmonary hypertension.

Pharmacological characterization and autoradiographic localization of a putative dopamine D4 receptor in the heart

1. The pharmacological profile and the anatomical localization of a putative dopamine D4 receptor were assessed in sections of rat and human atria and ventricles using combined radioligand binding and autoradiographic techniques with [3H]-spiperone as a ligand. 2. [3H]-Spiperone was bound specifically to sections of human and rat atria and ventricles. The binding was time-, temperature- and concentration-dependent, belonging to a single class of high-affinity sites. In atria, the dissociation constant value (Kd) was 0.45 nM in rats and 0.32 nM in humans, and the maximum density of binding sites (Bmax) was 31.6+/-2.9 fmol mg(-1) tissue in rats and 18.8+/-0.7 fmol mg(-1) tissue in humans. In ventricles, Kd was 0.38 nM in rats and 0.39 nM in humans, and the Bmax was 43.5+/-3.0 fmol mg(-1) tissue in rats and 56.4+/-3.2 fmol mg(-1) tissue in humans. 3. The pharmacological profile of [3H]-spiperone binding to sections of both rat and human atria and ventricles was consistent with the labelling of dopamine D2-like receptors. [3H]-Spiperone binding was more sensitive to displacement by the neuroleptic clozapine in sections of atria than of ventricles, suggesting the expression of a dopamine D4 receptor in atrial tissue. Moreover, preincubation of some sections with a dopamine D4 receptor antibody and subsequent exposure to [3H]-spiperone caused a remarkable decrease of radioligand binding to sections of atria, but only a slight reduction of binding to sections of ventricles. 4. Light microscope autoradiography revealed the accumulation of silver grains over atrial tissue within atrial myocardiocytes. A higher density of silver grains was developed in rat than in human atria. In ventricles, silver grains were accumulated primarily in cluster areas both in rats and in humans. 5. The above findings suggest the expression of a dopamine D4 receptor in rat atria, but not in ventricles. A similar site was identified in human atria. The possible relevance of a dopamine D4 receptor in the heart is discussed.

Age-dependent changes in the expression of dopamine receptor subtypes in human peripheral blood lymphocytes

The pharmacological profile and the density of dopamine D3 and D5 receptor subtypes expressed by human peripheral blood lymphocytes of subjects of different ages (ranging from 20 to 75 years) were assessed using radioligand binding techniques. Dopamine D3 receptor was assayed with [3H]7-hydroxy-N,N-di-n-propyl-2-aminotetraline ([3H]7-OH-DPAT) as a ligand. Dopamine D5 receptor was assayed using [3HIR]-(+)-(-chloro-2,3,4,5, tetrahydro-5-phenyl-1H-3-benzazepin-al-hemimaleate) ([3H]SCH 23390) as a ligand. The affinity and the pharmacological profile of [3H]7-OH-DPAT and [3H]SCH 23390 at dopamine D3 and D5 receptor, respectively, were similar in subjects of different ages. The density of dopamine D3 receptor binding sites was slightly decreased in subjects of 30-39 years in comparison with younger individuals. A remarkable loss of dopamine D3 receptor was then found between 40 and 49 years of age in comparison with younger subjects. A further slight decrease was noticeable between 50 and 59 years of age. The number of [3H]7-OH-DPAT binding sites was then stabilized after 60 years of age. The density of dopamine D5 receptor binding sites did not show age-dependent changes. The above findings indicate the occurrence of a decline in the density of lymphocyte dopamine D3 but not D5 receptor between adult and mature subjects. The possibility that dopamine D3 receptor assay in peripheral blood lymphocytes may represent a tool for investigating dopamine receptor function in aging and age-related neurological disorders is discussed.

Effect of treatment with L-deprenyl on age-dependent microanatomical changes in the rat kidney

The influence of aging and of treatment with L-deprenyl on the structure of the kidney was investigated in 24-month-cld male Sprague Dawley rats by microanatomical techniques associated with image analysis. L-Deprenyl was administrated orally for 5 months at a dose not inhibiting monoamine oxidase (MAO) B activity (1.25/mg/kg/day) and at a dose inhibiting MAO B activity (5 mg/kg/day). In 24 month-old-rats the number and the volume of glomeruli was reduced in comparison with 12-month-old rats used as reference adult animals. Vascular changes characterised by increased thickness of the tunica media, decreased size of arterial lumen and increased wall-to-lumen ratio were also noticeable in 24-month-old rats. Moreover, an increased MAO B reactivity was noticeable within glomerular tufts and renal tubules. Treatment with the low dose of L deprenyl did not cause changes in MAO B reactivity, or in the number of glomeruli, but increased glomerular volume and reduced the wall-to-lumen ratio in medium-sized renal artery branches. The dose of 5 mg/kg/day of L-deprenyl significantly decreased MAO B reactivity within both glomerular tufts and tubules, increased the number and the volume of glomeruli and countered-age-related vascular changes. The above results suggest that treatment with L-deprenyl counters to some extent microanatomical changes occurring in the kidney of aged rats. The observation that the dose of the compound inactive on MAO B activity reduces in part age dependent renal microanatomical changes, indicates that the renal protective effect of L-deprenyl is only in part related to MAO B inhibition.

Pharmacological characterisation of Ca2+ channels of the L-type in human peripheral blood lymphocytes

Ca2+ channels of the L-type were characterised in intact human peripheral blood lymphocytes using a radioligand binding technique and the dihydropyridine-type Ca2+ channel antagonist [3H](+)-PN 200-110 (isopropyl-4-(2,1,3-benzoxadiazol-4-yl)1,4-dihydro-5-methoxycarbon yl-2, 6-dimethyl-3-pyridine carboxylate) as a ligand. [3H](+)-PN 200-110 binding to human peripheral blood lymphocytes was time-, temperature-, concentration-dependent and of high affinity. The dissociation constant (Kd) value was 0.4 +/- 0.02 nM and the maximum binding capacity (Bmax) was 33.5 +/- 1.6 fmol/10(6) cells. Pharmacological analysis of [3H](+)-PN 200-110 binding to human peripheral blood lymphocytes was consistent with the labelling of a Ca2+ channel of the L-type. In fact, dihydropyridine derivatives were the most potent competitors of [3H](+)-PN 200-110 binding, whereas phenylalkylamine and benzothiazepine compounds or non-selective Ca2+ channel modulators were weak or ineffective displacers. These findings are the first observation that human peripheral blood lymphocytes express Ca2+ channels of the L-type. The possibility that Ca2+ channel antagonists may interfere with immune system function is discussed.

Serotonin is involved in the ACTH-induced reversal of hemorrhagic shock in anesthetized rats

In a rat model of volume-controlled hemorrhagic shock (mean arterial pressure = 20-24 mm Hg) causing the death of all saline-treated animals within 30 min, the i.v. bolus injection of ACTH-(1-24) (160 micrograms/kg) produced an almost complete and sustained reversal of the shock condition, with recovery of arterial blood pressure, pulse pressure and respiratory rate, and with 100% survival at the end of the experiment (2 h). The serotonin-depleting agent p-chlorophenylalanine (316 mg/kg i.p., administered 66-70 h before hemorrhage) almost completely prevented the effect of ACTH. The 5-HT1/5-HT2 receptor antagonist, methysergide, prevented the effect of ACTH completely when injected i.v. (5 mg/kg), but only in part when injected into a brain ventricle (i.c.v.) (15 micrograms/rat); the 5-HT2 antagonist, ketanserin, prevented the effect of ACTH completely when injected i.c.v. (1.5 micrograms/rat), but only in part when injected i.v. (0.5 mg/kg); the 5-HT3 antagonist, MDL 72222, largely prevented the effect of ACTH when injected i.c.v. (10 micrograms/rat), but had no influence at all when injected i.v. (3 mg/kg); finally, the 5-HT4 antagonist, GR 125487, had no effect when injected i.v. (5 micrograms/kg) or when injected i.c.v. (30 ng/rat). Overall, these data indicate that both CNS and peripheral serotonin play an important role in the complex mechanism of the ACTH-induced hemorrhagic shock reversal.

Protective effect of nicardipine treatment on cerebrovascular microanatomical changes in spontaneously hypertensive rats

1. The effect of long-term treatment with the dihydropyridine Ca2+ antagonist, nicardipine, on the morphology of different sized pial arteries was assessed in spontaneously hypertensive rats (SHR) using histological techniques associated with image analysis. 2. In control 20 week old SHR blood pressure values, the thickness of the tunica media, the media-to-lumen ratio and connective tissue content were significantly increased in comparison with reference normotensive Wistar-Kyoto (WKY) rats. 3. Treatment for 8 weeks with a daily dose of 3 mg/kg of nicardipine decreased blood pressure values in SHR and significantly reduced the area occupied by the tunica media and the media-to-lumen ratio. This effect was observed primarily in small sized pial arteries and to a lesser extent in medium sized pial arteries. Nicardipine administration was without effect on connective tissue content in the wall of cerebral arteries. 4. These results indicate that treatment with nicardipine reduces blood pressure elevation in SHR and exerts a protective effect on arteries controlling cerebrovascular resistance. The activity of the compound primarily on small sized pial arteries may protect the brain from generalized vasodilation which could cause cerebral hypoperfusion.

Influence of long-term treatment with the dihydropyridine-type calcium antagonist nicardipine on renal microanatomical changes in spontaneously hypertensive rats

1. The influence of hypertension and treatment with the dihydropyridine-type Ca2+ antagonist, nicardipine, on the structure of the kidney was assessed in spontaneously hypertensive rats (SHR) of 12 weeks of age. Treatment went for 8 weeks with a daily oral dose of 1 mg/kg of nicardipine. 2. Control SHR exhibited hypertension and microanatomical vascular and glomerular changes. Vascular changes consisted of a thickening of the tunica media and decreased luminal area of medium- and small-sized intrarenal artery branches. Glomerular changes included glomerulosclerosis and atrophy of varying degrees. 3. Administration of nicardipine significantly reduced blood pressure. The drug also decreased the thickening of tunica media and luminal narrowing of renal artery branches as well as the degree of glomerular injury in SHR. 4. These data indicate that nicardipine treatment is able to control elevated blood pressure in SHR, and to counter hypertension-dependent microanatomical impairment of the kidney. This suggests that the compound exerts a protective effect on hypertensive kidney.

Localization of calcium channels of the L-type in human epicardial arteries: a light microscope autoradiographic study

The anatomical localization of Ca2+ channels of the L-type was analyzed in sections of the human right and anterior interventricular coronary arteries by using in vitro light microscope autoradiography associated with radioligand binding techniques. [3H]Nicardipine was utilised as a ligand. Binding of the radioligand to sections of the two coronary arteries was time-, temperature- and concentration-dependent. Analysis of binding isotherms revealed a dissociation constant value of about 0.5 nM in the two arteries and maximum binding capacities of 139 +/- 6.4 fmol/mg tissue for the right coronary artery and of 173 +/- 9.5 for the anterior interventricular branch. The pharmacological profile of [3H]nicardipine binding to sections of human coronary arteries was consistent with the labelling of Ca2+ channels of the L-type. Dihydropyridine derivatives were the most powerful competitors of [3H]nicardipine binding, whereas phenylalkylamines, benzothiazepine or non-selective channel modulators were weak competitors or ineffective. Light microscope autoradiography revealed the highest density of [3H]nicardipine binding sites in the tunica media of the coronary arteries. In this layer Ca2+ channels of the L-type are located within smooth muscle cells. A lower accumulation of the radioligand occurred in the tunica adventitia, whereas no specific binding was found in the tunica intima. Study of the localization of Ca2+ channels in sections of human coronary arteries may contribute to a better understanding of the mechanism of the marked coronary dilatory activity elicited by Ca2+ antagonists demonstrable in both in vitro preparations and in vivo.

Pharmacological characterisation and autoradiographic localisation of dopamine receptor subtypes in the cardiovascular system and in the kidney

Combined radioligand binding and light microscope autoradiography techniques were used for investigating the pharmacological profile and the microanatomical localisation of dopamine receptor subtypes in the cardiovascular system and in the kidney. In superior mesenteric and renal arteries the predominant dopamine D1-like receptor belongs to the D5 (or D1b) subtype. This site is located within smooth muscle of the tunica media. The same receptor subtype predominates in the kidney, where it has a vascular and tubular localisation. The dopamine D2-like receptor subtype expressed by systemic arteries belongs to the D2 receptor subtype. It has a prejunctional and endothelial localisation. In the kidney the predominating dopamine D2-like receptor belongs to the dopamine D3 subtype. Atria but not ventricles express dopamine D2-like receptors belonging to the D4 receptor subtype. The above results suggest that in spite of the emerging complexity of the dopamine receptor profile demonstrated by molecular biology techniques, radioligand binding and autoradiographic techniques, if performed with appropriate radioligands and/or in the presence of compounds active on specific receptor subtypes, may represent a useful tool for better understanding the biological significance of peripheral dopamine receptors.

Effect of long-term treatment with the dihydropyridine-type calcium channel blocker darodipine (PY 108-068) on the cerebral capillary network in aged rats

The effects of treatment with the dihydropyridine Ca+2 antagonist darodipine (PY 108-068) on age-related changes in the cerebral capillary network was studied using alkaline phosphatase histochemistry with quantitative image analysis. The investigation was performed on male Wistar rats of 12 months (adult reference group) and 27 months. The 27-month-old rats consisted of two groups, the first of control untreated animals and the second of rats receiving an oral dose of 5 mg/kg/day of darodipine from the 21st to the 27th month. The cerebral areas examined included the frontal cortex, the occipital cortex, Ammon's horn of the hippocampus, and the dentate gyrus. The number and the average length of alkaline phosphatase-positive capillaries were decreased in old rats, when compared with adult rats. The intercapillary distance, which is considered as a sensitive parameter for capillary density was increased in aged rats in comparison to adult rats. The capillary diameter was increased slightly or unchanged in old rats. The Ammon's horn and the frontal cortex were the cerebral areas most affected by age-dependent changes of the capillary network. Treatment with darodipine increased the number and the average length of alkaline phosphatase-reactive capillaries and reduced the intercapillary distance and the diameter of cerebral capillaries in old rats. The pericapillary microenvironment of the Ammon's horn was the most sensitive to treatment with darodipine. The above results showed that treatment with darodipine is capable of counteracting some microvascular changes occurring in the brain of aged rats. This suggests that the blockade of dihydropyridine-type Ca2+ channels has a positive effect on the brain microvascular system and may counteract the impairment of pericapillary microenvironment occurring with aging.

Effect of long term isradipine treatment on the morphology of the endothelium in the aorta of spontaneously hypertensive rats

The influence of hypertension and of treatment with the dihydropyridine calcium channel blocker isradipine on the morphology of the thoracic aorta and of the aortic tunica intima were studied. Three experimental groups of male spontaneously hypertensive rats (SHR) of 10 weeks of age were used. Two groups were treated with a daily oral dose of 0.01 mg/kg or of 0.1 mg/Kg of isradipine respectively. A third group of SHR was left untreated and served as control. Age-matched normotensive Wistar-Kyoto (WKY) rats were used as a reference group. Animals were allowed to survive for 12 weeks and were killed at 22 weeks of age. Systolic pressure values which did not change in WKY rats, significantly increased in SHR as a function of age. The dose of 0.1 mg/Kg/day isradipine reduced systolic pressure to normotensive values after the first week of treatment, whereas the lower one was ineffective. The area of the wall, the area of the tunica media and the wall-to-lumen ratio of the aorta significantly increased in SHR and decreased either with the antihypertensive and non-antihypertensive doses of isradipine. Transmission and scanning electron microscope analysis of the tunica intima revealed hypertrophy of the endothelial cells with an increase in sub endothelial space in SHR. An improvement of the endothelial morphology and a decrease in sub endothelial space was noticeable in isradipine-treated SHR. Although the hypotensive dose of the compound was the most effective, the non-hypotensive dose was active was well. The above results suggest that isradipine treatment may counter structural changes of the aorta of SHR and has a protective action on the hypertension-dependent modifications of the endothelium. The endothelial effects are probably dependent only in part by the hypotensive activity of the compound.

Long term choline alfoscerate treatment counters age-dependent microanatomical changes in rat brain

1. The density of nerve cells and of silver-gold impregnated fibres were evaluated in the hippocampus and in the cerebellar cortex in adult (12-month-old) and old (24-month-old) Sprague-Dawley rats. 2. The effects of long-term choline alfoscerate (GFC) treatment (100 mg/Kg/day for 6 months) on the above parameters were investigated in old rats. 3. The number of nerve cell profiles and the area occupied by silver-gold impregnated fibres were decreased both in the hippocampus and in the cerebellar cortex in old in comparison with adult rats. 4. GFC treatment countered the age-dependent reduction of nerve cells and silver-gold impregnated fibres. The hippocampus was more sensitive than the cerebellar cortex to the activity of GFC. 5. These results suggest that GFC treatment is effective in slowing down the expression of structural changes occurring in aging brain.

Influence of treatment with L-deprenyl on the structure of the cerebellar cortex of aged rats

Treatment with L-deprenyl increases mean and maximum life span in the rat and reverses memory and learning deficits associated with old age. Since only sparse information is available concerning the influence of L-deprenyl administration on the aging brain microanatomy, we have investigated the effect of long-term treatment with L-deprenyl on the structure of the cerebellar cortex in the aged rat. The cerebellar cortex was used since it represents a useful model for assessing age-related changes in nervous system anatomy and function. Male Sprague-Dawley rats were treated from the 19th to the 24th month of age with a daily oral dose of 1.25 mg/kg or 5 mg/kg L-deprenyl. Age-matched rats were left untreated and used as a control group. Eleven-month-old untreated rats were used as an adult reference group. The density of Purkinje and granule neuron profiles as well as the intensity of Nissl's staining within the cytoplasm of Purkinje neurons were reduced in 24-month in comparison with 11-month rats. Moreover, an increased accumulation of lipofuscin was noticeable in the cytoplasm of Purkinje neurons of old rats as well as an increase in MAO-B activity in the molecular layer of the cerebellar cortex. The two doses of L-deprenyl increased the density of both Purkinje and granule neuron profiles and the intensity of Nissl's staining in the cytoplasm of Purkinje neurons and reduced lipofuscin deposition within Purkinje neurons. The lower dose of L-deprenyl caused only a slight decrease in MAO-B activity, whereas the 5-mg/kg/day dose remarkably reduced it. These results suggest that long-term treatment with L-deprenyl counters the expression of some age-related microanatomical changes in the rat cerebellar cortex. The possible independence of the effects of the compound on age-related microanatomical changes of the cerebellar cortex and on MAO-B inhibitory activity is discussed.

Protective effect of nicardipine treatment on renal microanatomical changes in spontaneously hypertensive rats

The effects of nicardipine administration on kidney morphology were studied in spontaneously hypertensive rats (SHR). Male 12-week-old SHR received an oral dose of 1 mg/Kg/day of nicardipine or vehicle for 8 weeks Age-matched Wistar-Kyoto rats were used as normotensive reference animals. At 20 weeks, the non treated SHR exhibited hypertension, albuminuria, decreased urinary sodium excretion and renal microanatomical changes. These changes were characterized by vascular alterations consisting in hypertrophy of the tunica media accompanied by a decrease of luminal surface. Glomerular changes consisting primarily in signs of glomerulosclerosis of varying degrees were noticeable in the kidneys of SHR. Treatment with nicardipine significantly reduced blood pressure and albuminuria and increased urinary sodium excretion. Moreover, hypertrophy of the tunica media and the luminal surface were decreased and increased respectively in nicardipine-treated SHR. The above results suggest that treatment with nicardipine reduces blood pressure in SHR and counteracts hypertension-dependent changes in the morphology of the kidney. The protective effect of the drug on hypertensive changes of renal microanatomy probably have functional relevance given of the influence of nicardipine treatment on albuminuria and urinary sodium excretion in SHR.

Quantitative image analysis study of the cerebral vasodilatory activity of nicardipine in spontaneously hypertensive rats

The effect of the Ca2+ channel blocker nicardipine on the circle of Willis and the different sized pial arteries was assessed in 20-week-old spontaneously hypertensive rats (SHR) using quantitative image analysis techniques. Normotensive Wistar Kyoto (WKY) rats were also used as a normotensive reference group. In SHR a significant increase of systolic blood pressure (SBP) is noticeable in comparison with WKY rats. The media-to-lumen ratio was increased in the circle of Willis arteries, large sized (diameter > than 150 microns), medium sized (diameter between 150 and 50 microns) and small sized (diameter < than 50 microns), pial artery branches. An increase in the thickness of the tunica media and a luminal narrowing was also seen in medium and small sized pial arteries of SHR in comparison with WKY rats. Treatment with an oral dose of 10 mg/Kg of nicardipine 3 h before the sacrifice significantly reduced SBP in SHR. The drug was without effect on circle of Willis and on large sized pial arteries. Moreover, treatment with nicardipine reduced the thickness of the tunica media, the media-to-lumen ratio and increased the luminal area in medium and small sized pial artery branches. These findings show that treatment of SHR with nicardipine significantly reduces SBP and causes a moderate vasodilatation of arteries regulating cerebrovascular resistance. This property may be useful in avoiding generalized or exaggerated cerebrovascular dilatation which could be accompanied by impaired brain perfusion in hypertension.

Influence of treatment with the calcium channel blocker darodipine (PY 108-068) on the morphology of pial and coronary arteries in spontaneously hypertensive rats

The present study was designed to assess the influence of treatment with the calcium channel blocker darodipine (PY 108-068) on the morphology of pial and coronary arteries in spontaneously hypertensive rats (SHR). Twelve week male SHR were used in this study. One group was treated with a daily dose of 5 mg/Kg of darodipine, while the control group of SHR was treated with placebo. Age-matched normotensive Wistar Kyoto (WKY) rats were used as a reference group. After 12 weeks of treatment the rats were sacrificed. The brains and the hearts were removed, embedded in resin, cut and used for light microscope analysis. Darodipine treatment reduced blood pressure in SHR. Morphometric analysis of different sized pial and coronary arteries revealed decreased arterial lumen in SHR in comparison with WKY rats. The area occupied by the tunica media and the media-to-lumen ratio were increased in SHR in comparison with WKY rats. In darodipine-treated rats the area occupied by the arterial lumen was increased in comparison with control SHR, whereas the area occupied by the tunica media and the media-to-lumen ratio were decreased. Pial arteries were more sensitive than coronary arteries to darodipine treatment. Medium and small sized pial and coronary arteries were most sensitive to darodipine treatment. Large-sized coronary artery branches were unaffected by pharmacological treatment. The above results suggest that treatment of SHR with darodipine is able to reduce high blood pressure and to counter the development of structural changes of pial and coronary arteries noticeable in SHR. The higher sensitivity of the cerebral vasculature to darodipine treatment is discussed.

Influence of isradipine treatment on the morphology of the aorta in spontaneously hypertensive rats

OBJECTIVE

To investigate the influence of hypertension and of treatment with the vasodilator hydralazine or with the dihydropyridine calcium antagonist isradipine on the morphology of the thoracic aorta in spontaneously hypertensive rats (SHR).

DESIGN

The systolic blood pressure (SBP), body weight and morphology of the thoracic aorta were evaluated. The ultrastructure of the smooth muscle component of the aorta and of the tunica intima were analysed by transmission and scanning electron microscopy.

METHODS

The SHR were divided into three groups: a control group, which was left untreated, and two treatment groups, one with 1 mg/kg per day hydralazine and the other with 0.1 mg/kg per day isradipine. Three age-matched groups of Wistar-Kyoto (WKY) rats were included in the study: one group was left untreated and was used as a normotensive reference group, the other two groups were treated with 1 mg/kg per day hydralazine or with 0.1 mg/kg per day isradipine.

RESULTS

The SBP did not change in the WKY rats treated with hydralazine, with isradipine or untreated, but was significantly increased in the SHR as a function of age. Both hydralazine and isradipine significantly reduced the SBP in the SHR after the second week of treatment. Light microscopy analysis of the thoracic aorta revealed thickening of the wall of the tunica media as well as an increase in the wall: lumen ratio in the SHR. Treatment with hydralazine had no effect on the morphometric parameters evaluated, whereas isradipine administration significantly reduced the thickening of both the wall and the tunica media of the aorta, and reduced the wall: lumen ratio. No significant modifications in the structure of the thoracic aorta were noticed in the hydralazine- or isradipine-treated WKY rats compared with untreated WKY rats. Transmission and scanning electron microscopy analysis demonstrated in control SHR hypertrophy of smooth muscle cells of the tunica media, an increased size and impairment of the internal elastic lamina, and a widening of the subendothelial space. Hypertrophy of the endothelium was also noticeable in the SHR. Treatment with isradipine reduced the hypertrophy of smooth muscle cells of the tunica media and the structural impairment of the tunica intima. No effect of isradipine treatment on the morphology of the aorta was noticed in the WKY rats.

CONCLUSION

The present results show that the effect of isradipine was different from that of hydralazine. Both compounds lowered the SBP, but only isradipine countered the structural changes of the aorta in the SHR. The effect of isradipine administration is particularly pronounced on the hypertension-dependent changes of endothelium. This suggests that isradipine may have a protective effect on the endothelium.

Interactions between endothelin and the dihydropyridine-type calcium antagonist nicardipine in the human renal artery: a radioligand and autoradiographic study

The interactions between dihydropyridine Ca2+ channels and endothelin were analysed using combined radioligand binding and autoradiographic techniques. Endothelin is a potent constrictor peptide of arterial smooth muscle. Endothelin-induced vasoconstriction is attenuated by dihydropyridine-type Ca2+ antagonists such as nicardipine. However, the molecular mechanisms of this effect are not yet understood. Sections of the human renal artery bound [3H]-nicardipine in a manner consistent with the labelling of dihydropyridine-type Ca2+ channels. The highest density of [3H]-nicardipine binding sites occurred within the tunica media of the renal artery, probably over smooth muscle. A lower density of [3H]-nicardipine binding sites was noticeable in the tunica adventitia, whereas no specific binding occurred in the tunica intima. Endothelin-1, from a concentration of 1 pM l-1, reduced [3H]-nicardipine binding as a function of concentration. A 10 nM endothelin concentration reduced [3H]-nicardipine binding by about 85%. The isoform, endothelin-3, had little effect on [3H]-nicardipine binding. The above findings suggest the occurrence of an interaction, probably at the receptor level, between [3H]-nicardipine binding and endothelin-1. This interaction probably accounts for the attenuation of endothelin-1-elicited vasoconstriction induced by nicardipine.

Dopamine D1 receptors are involved in the ACTH-induced reversal of hemorrhagic shock

In an experimental model of volume-controlled hemorrhagic shock causing the death of all rats within 30 min, the intravenous (i.v.) bolus injection of the adrenocorticotropic hormone fragment 1-24 (ACTH-(1-24)) (160 micrograms/kg) induced a prompt and sustained improvement of cardiovascular and respiratory function, with 100% survival 2 h after treatment. Pretreatment with either haloperidol, 300 micrograms/kg i.v. (antagonist at dopamine D1 and D2 receptors), or (R)-(+)-8-chloro-2,3,4,5-tetrahydro-3-methyl-5-phenyl-1H-3- benzazepin-7-ol hemimaleate (SCH 23390), 50 micrograms/kg intraperitoneally (selective antagonist at dopamine D1 receptors), significantly inhibited the effect of ACTH-(1-24). A complete inhibition was produced by intracerebroventricular pretreatment with SCH 23390 (0.1 micrograms/rat). On the other hand, both i.v. and i.c.v. pretreatment with l-sulpiride (selective antagonist at dopamine D2 receptors) (25 mg/kg and 80 micrograms/rat, respectively) had only minor effects. These data suggest that the mechanism of the ACTH-induced reversal of hemorrhagic shock involves the activation of dopamine D1 receptors in the brain.

Microanatomical changes in the frontal cortex of aged rats: effect of L-deprenyl treatment

The present study was designed to assess whether treatment with L-deprenyl has any effect on the age-related microanatomical changes in the rat frontal cortex. Male Sprague-Dawley rats of 19 months of age were treated until the 24th month with an oral daily dose of 1.25 mg/kg or of 5 mg/kg of L-deprenyl. Eleven-month-old untreated rats were used as an adult reference group. The density of nerve cell profiles and of glial fibrillary acidic protein-(GFAP) immunoreactive astroglial profiles, lipofuscin accumulation within the cytoplasm of pyramidal neurons, and MAO-B reactivity were assessed. A decreased density of nerve cell profiles and an increased density of astroglial profiles as well as augmented lipofuscin deposition and MAO-B reactivity were observed in the frontal cortex of rats of 24 months in comparison with 12-month-old animals. In the frontal cortex of rats treated with 5 mg/kg/day L-deprenyl, which is a dose inhibiting MAO-B activity, the density of nerve cell and GFAP-immunoreactive astrocyte profiles is increased and decreased respectively in comparison with age-matched untreated subjects. Lipofuscin deposition is reduced. The lower dose of L-deprenyl (1.25 mg/kg/day) which did not affect MAO-B activity, decreased lipofuscin deposition but was without effect on the density of nerve cell or GFAP-immunoreactive astrocyte profiles. The above findings suggest that treatment with L-deprenyl is able to counter some microanatomical changes occurring in the frontal cortex of aged rats. Some of these effects are probably not related to the inhibitory MAO-B activity of the compound.

Influence of isradipine treatment on left ventricular and coronary vascular hypertrophy in spontaneously hypertensive rats

The purpose of this study was to ascertain if Isradipine treatment in spontaneously hypertensive rats (SHR) decreased hypertension-dependent left ventricular and coronary vascular hypertrophy. Twelve week male SHR were used in this study; one group of SHR was treated with Isradipine while the control group of SHR was left untreated. Age-matched normotensive Wistar-Kyoto rats (WKY) were utilized as a reference group. After 12 weeks of treatment rats were sacrificed. The hearts were removed and morphometric analysis was performed on the left ventricles. Isradipine treatment reduced systolic blood pressure in SHR. The heart/body weight ratio significantly increased in SHR and in Isradipine-treated SHR in comparison with WKY rats. Isradipine treatment decreased the left ventricular muscle fibre diameter and decreased the amount of focal necrosis in SHR. Different sized coronary arteries were also examined using a light microscope and an image analyzer. We found that the area occupied by the medial layer and the media-to-lumen ratio were significantly increased in comparison with WKY rats. In Isradipine-treated SHR the area of the medial layer and the media-to-lumen ratio in small and medium sized but not in large sized coronary arteries were significantly reduced in comparison with untreated SHR. The above results suggest that long term Isradipine treatment is not only able to reduce high blood pressure in SHR but is also able to counter the development of certain morphological changes often seen in the hypertensive heart and coronary arteries.

Autoradiographic localization of [3H]nicardipine binding sites in the human renal artery

In the present study the pharmacological profile and the anatomical distribution of dihydropyridine-type Ca2+ channels were analyzed in sections of the human renal artery by the use of combined radioligand binding and autoradiographic techniques with [3H]nicardipine as a ligand. The binding of [3H]nicardipine to sections of renal artery was time-, temperature- and concentration-dependent belonging, at least in the range of radioligand concentrations used, to a single class of high-affinity binding sites. The dissociation constant (KD) value was 0.3 nM and the maximum density of binding sites (Bmax) was 248 +/- 16 fmol/mg tissue. The pharmacological profile of [3H]nicardipine binding to sections of human renal artery was consistent with the labeling of dihydropyridine-type Ca2+ channels. In fact, dihydropyridine derivatives were the most powerful competitors of [3H]nicardipine binding, whereas phenylalkilamine, benzothiazepine or non-selective channel modulators were weak or ineffective competitors. Light microscope autoradiography revealed the highest density of [3H]nicardipine binding sites in the tunica media of the renal artery, probably within smooth muscle cells. A smaller accumulation of the radioligand occurred in the tunica adventitia, whereas the tunica intima did not show specific binding. These results indicate that light microscope autoradiography techniques associated with radioligand binding may represent a useful tool for analyzing the localization of receptors or targets of drug action within the arterial wall.

Structural changes in the endothelium of the femoral artery of spontaneously hypertensive rats: sensitivity to isradipine treatment

OBJECTIVE

The present study was designed to investigate the influence of hypertension and of long-term treatment with the dihydropyridine calcium antagonist isradipine on the morphology of the femoral artery in spontaneously hypertensive rats (SHR).

DESIGN

Systolic blood pressure (SBP), body weight and morphology of the femoral artery were evaluated, and the ultrastructure of the endothelium was analysed by transmission and scanning electron microscopy.

METHODS

SHR were divided into three groups, a control group which was left untreated and two isradipine treatment groups, one at 0.01 mg/kg per day and the other at 0.1 mg/kg per day. Two age-matched groups of Wistar-Kyoto (WKY) rats were included in the study; one group was left untreated and was used as a normotensive reference group and the other was treated with isradipine at 0.1 mg/kg per day. The study lasted 12 weeks.

RESULTS

SBP did not change in the WKY rats, whether treated with isradipine or not, but was significantly increased in SHR as a function of age. The lower dose of isradipine did not alter SBP in the SHR, but the higher dose brought SBP values into the normal range after the first week of treatment. Light microscopy of sections of the femoral artery did not reveal any structural differences in the five rat groups examined. Both transmission and scanning electron microscopy showed endothelial alterations in the SHR, together with thickening of the internal elastic lamina. Treatment with isradipine significantly improved the morphology of the endothelium in SHR. The higher dose was more effective, but the lower dose partly countered the hypertension-dependent changes in the morphology of the endothelium. No significant modifications to the structure of the endothelium were noticed in isradipine-treated WKY rats compared with untreated WKY rats.

CONCLUSIONS

The results show that structural changes occur in the endothelium of the femoral artery of SHR and that isradipine treatment has a protective effect. This protective effect is probably only partly dependent on the antihypertensive properties of the compound.