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Biomedical subjects

A Moretti

Publications and source records attributed to A Moretti.

At least 73 records · Page 4Linked to original sources
PubMed1998

Is there a rationale for the use of acetylcholinesterase inhibitors in the therapy of Alzheimer's disease?

Since the 1980s, the cholinergic hypothesis of the pathogenesis of Alzheimer's disease has proven to be a strong stimulus to pharmacological strategies aimed at correcting the cognitive deficit by manipulating cholinergic neurotransmission. Among these strategies, the one based on acetylcholinesterase inhibition is currently the most extensively developed for the therapy of Alzheimer's disease. The inhibitors' mechanisms of action are complex, including changes in the release of acetylcholine, and modulation of acetylcholine receptors. Various clinical trials of various inhibitors have shown that, on the whole, their effects were modest and, in the case of some drugs, were associated with frequent adverse reactions. Among the conceivable reasons for the limited efficacy of these drugs, those related to the pharmacological target deserve particular attention. This review, therefore, focuses on the complex nature of the acetylcholine system, the alterations of acetylcholinesterase and muscarinic receptor signal transduction in Alzheimer's disease, and the involvement of other neurotransmitters.

Acetylcholinesterase↗
PubMed1998

Analysis of CDKN2A, CDKN2B, CDKN2C, and cyclin Ds gene status in hepatoblastoma.

The status and the expression of cyclin-dependent kinase inhibitor A (CDKN2A) family genes, named CDKN2A, CDKN2B, and CDKN2C and of cyclin Ds (D1, D2, and D3) genes were investigated in 14 cases of human hepatoblastomas. These genes were selected because: 1) CDKN2A and CDKN2B are very frequently inactivated in human cancers; 2) cyclin Ds are overexpressed in several tumors and 3) CDKN2A is posttranscriptionally silenced in hepatocellular carcinomas. Structural analysis of the CDKN2A, CDKN2B, and CDKN2C genes in hepatoblastoma cases showed the absence of deletions and/or point mutations. Moreover, a detailed investigation of loss of heterozygosity at 9p21 and 1p32 (the chromosomal regions where CDKN2A genes are located) rules out the possible loss of one allele. Messenger RNA (mRNA) analysis showed that CDKN2C is expressed in all hepatoblastoma samples studied, while both CDKN2A and CDKN2B genes are not transcribed in the cancer specimens as well as in the matched normal liver tissues. Interestingly, an alternative mRNA expressed by the CDKN2A gene (beta-transcript) is detectable in 100% of the samples investigated. The analysis of cyclin D genes expression revealed that cyclin D1 is highly transcribed in normal hepatic tissue while cyclin D2 or D3 genes were extensively expressed in the matched transformed samples. Investigation at protein level confirmed the data obtained on RNA analysis. Indeed, p16INK4A and p15INK4B (products of expression of CDKN2A and CDKN2B respectively) were not observable while pl8INK4C (which is codified by CDKN2C) was clearly detectable in the samples analyzed. Moreover, a noticeable decrease of cyclin D1 content and increase of cyclin D3 level were observable in tumor tissues versus normal counterparts. Our findings demonstrated the following: 1) CDKN2A, CDKN2B, and CDKN2C genes are structurally unmodified in human hepatoblastoma, and 2) CDKN2A (alpha-transcript) and CDKN2B are transcriptionally silenced in normal liver whereas CDKN2A (beta-transcript) and CDKN2C were clearly expressed. Finally, a clear shift in cyclin D type expression was observable during malignant transformation. These results show that CDKN2A gene family alterations are not involved in hepatoblastoma development, whereas changes in cyclin D types might play a role in this type of tumor. Furthermore, a highly regulated expression of CDKN2A seems to occur in normal hepatic tissue.

Carrier Proteins↗
PubMed1998

Methanol Laser Line Assignments: Evidence of Four-Level Laser Systems

The "Ritz" computer program, developed for facilitating the assignment of molecular Fourier transform absorption spectra and described in a previous work, determines the energy level values involved in the assigned transitions by the Rydberg-Ritz combination principle. Combining the data obtained from the analyses of high-resolution infrared (IR) and far-infrared (FIR) spectra, it is possible to predict possible FIR laser emissions of molecules. In the present work we have applied this method to the common isotopomer methanol, 12CH3 16OH, and obtained 14 proposed assignments for previously unassigned FIR laser lines. We also predict 15 possible new FIR laser emissions. For the first time, an assignment involving a four-level laser system with collisional population transfer to a slightly higher energy level is reported. Copyright 1998 Academic Press.

Journal Article↗
PubMed1998

Effects of long-term pravastatin treatment on spermatogenesis and on adrenal and testicular steroidogenesis in male hypercholesterolemic patients.

To evaluate the influence of an hydrophilic statin, pravastatin, on adrenal and testicular steroidogenesis and spermatogenesis, eight male hypercholesterolemic patients were studied. All patients observed a hypocholesterolemic diet and received placebo for 4 weeks followed by pravastatin (20 mg/die) for 6 months. Before, during (4th-5th week) and at the end (23th-24th week) of active treatment, CRH (1 microgram i.v.), ACTH (Synacthen 250 micrograms i.v.) and human CG (HCG 3000 IU i.m.) tests were performed in addition to semen analysis. Pravastatin significantly reduced total cholesterol (20.3%), calculated LDL-cholesterol (24.6%) and apolipoprotein B (10.5%, increased apolipoprotein A1 (16.1%) and did not influence plasma HDL-cholesterol and triglycerides. Basal plasma cortisol, aldosterone, androstenedione, testosterone and oestradiol did not change under active treatment. Pravastatin administration affected neither adrenal hormone responses to CRH and ACTH or testicular response to HCG nor spermatogenesis in respect of motility, morphology and sperm count. In conclusion, long-term pravastatin treatment, at doses effective in improving lipid profile, did not influence testicular reproductive and endocrine function and did not interfere with basal and stimulated adrenal activity of male hypercholesterolemic patients.

Adrenal Glands↗
PubMed1998

Utility of plasma dehydroepiandrosterone sulphate determination in adrenal incidentalomas.

To evaluate whether low DHEA-S levels are predictors of cortical origin, benignity and hormonal activity in incidentally detected adrenal masses, thirty-five patients with adrenal incidentalomas were studied. All patients were operated on and the diagnosis was histologically confirmed. Basal endocrine workup included plasma determination of cortisol before and after dexamethasone (1 mg overnight), plasma ACTH (08:00 h), 17-OH-progesterone, testosterone and potassium, standing plasma renin activity and aldosterone, supine and standing plasma noradrenaline and adrenaline. If necessary, we performed dexamethasone suppression tests at low (2 mg) and high (8 mg) doses, or the loperamide test (16 mg os) for evaluation of glucocorticoid activity and the glucagon test (1 mg i.v.) for exploring adrenal medulla function. Plasma DHEA-S was measured in all patients and the results were compared to those obtained in controls matched for age, sex and menopausal status. Suppression of DHEA-S was found in 11 out of 35 patients (31.5%). However, this hormonal finding occurred in 50% of the extracortical adrenal lesions, while in proven cortical adenomas (no. = 19) it was detected in only 5 patients (26.3%). Sensitivity, specificity, diagnostic accuracy and positive predictive value of low DHEA-S in indicating a cortical origin of the mass were 0.27, 0.0, 0.25, and 0.80. In malignancies (no. = 6) low DHEA-S levels were found in 1 out of 2 metastases and never in cortical carcinomas. Sensitivity, specificity, diagnostic accuracy and positive predictive value of low DHEA-S in indicating a benign form were 0.34, 0.83, 0.42, and 0.91. Six out of 19 patients with cortical adenomas showed signs of hypothalamic-pituitary adrenal (HPA)-axis dysfunction. Low DHEA-S levels were found in 50% of adenomas with HPA-axis abnormality and in 15.3% of adenomas without hormonal activity. Sensitivity, specificity, diagnostic accuracy, and positive predictive value of low DHEA-S levels in indicating hormonal activity of the mass were 0.50, 0.84, 0.73, and 0.60. Our data indicate that the association between low DHEA-S levels and adrenal incidentalomas is frequent. Low DHEA-S appears to be a poor predictor of hormonal activity with low sensitivity and specificity in respect of cortical origin and benignity of the mass. In conclusion, our results show that DHEA-S measurement does not offer relevant clinical information in the management of adrenal incidentalomas.

Adenoma↗
PubMed1998

Sixty adrenal masses of large dimensions: hormonal and morphologic evaluation.

OBJECTIVES: To evaluate the nature and function of adrenal masses of large dimensions (macrotumors). METHODS: Sixty consecutive patients (31 women, 29 men, age range 15 to 84 years) with adrenal masses 4.0 cm in diameter or larger (range 4.0 to 15.0 cm) underwent morphologic study by computed tomography (CT); the majority also underwent 131-I-6beta-norcholesterol (131I-NC) or 131I-MIBG scintigraphy. Basal evaluation of glucocorticoids, mineralcorticoids, and catecholamines was performed in all patients, and in 38 cases determination of androgens was also made. In addition, on the basis of various clinical suspicions, a dynamic hormonal study was performed. RESULTS: Macrotumors were benign in 78.3% of cases and included pheochromocytomas (n = 17), nonfunctioning cortical adenomas (n = 12), and cortisol-secreting tumors (n = 7, Cushing's syndrome). Malignant forms were 21.7% of the total, including pheochromocytomas (n = 3), cortical carcinomas (n = 6), and metastases (n = 4). On CT, malignant masses were larger (8.4+/-0.9 cm) than benign ones (5.7+/-0.3 cm) (P < 0.0001) and the mass size was strictly related to malignancy (P < 0.03). CT did not offer other diagnostic criteria for malignancy, except irregular margins and regional lymph node enlargement, which were more frequently (P < 0.0001) found in malignant forms. 131I-MIBG scintigraphy showed tracer uptake in all pheochromocytomas, both benign and malignant. By contrast, on 131I-NC scintigraphy, cortical malignancies never accumulated the radiotracer, whereas uptake was observed in all cases of solid cortical benign adenomas. Patients with cortical carcinomas showed plasma sex steroids above the normal range, pheochromocytomas were asymptomatic in 15% of cases, and almost half of the patients with Cushing's syndrome did not show clinical features of the disease (pre-Cushing's syndrome). CONCLUSIONS: Adrenal macrotumors frequently show endocrine activity and the medulla seems to be involved more than the cortex. Pheochromocytomas and cortisol-secreting adenomas are sometimes asymptomatic. Malignancy is often found in macromasses and, at least for the cortical forms, size of the tumor on CT, 131I-NC uptake on scintigraphy, and determination of levels of sex steroids seem to be useful criteria for predicting the nature of the mass.

Adolescent↗
PubMed1998

Endogenous digitalis-like factor and ouabain immunoreactivity in adrenalectomized patients and normal subjects after acute and prolonged salt loading.

The aim of our study was to evaluate whether adrenals are involved in the secretion of endogenous digitalis-like factor(s) with polarity similar to (or less than) that of ouabain (EDLF-1), and whether acute plasma volume expansion is a physiological releasing stimulus for this factor(s) in humans. For this purpose, we measured the concentration of this substance(s) by a human placenta radioreceptor assay (RRA) and by the Du-Pont-NEN ouabain-EIA (immunoreactive ouabain, I-Oua) in plasma C18-extracts of eight normotensives and six patients with bilateral adrenalectomy before and after acute salt loading (2 lt 0.9% NaCl/2 h). The study was repeated after 2 weeks of increased sodium intake (200 mEq/day). Under basal conditions, EDLF-1 by RRA and I-Oua were similar in adrenalectomized patients and in controls and were not significantly modified by saline infusion. After 15 days of high sodium intake, basal plasma EDLF-1 and I-Oua were not significantly different from prediet levels, both in adrenalectomized patients and controls and were likewise unaffected by saline loading. Saline infusion, by contrast, significantly (P < or = .05) suppressed hematocrit and PRA and increased ANP both in controls and in patients, either before or after prolonged high dietary sodium. Plasma aldosterone (ALD) was similarly reduced (P < .001) in controls and, as expected, was undetectable in adrenalectomized patients. Our data indicate that in adrenalectomized patients circulating levels of EDLF-1 and I-Oua are similar to those of controls and that, in both groups, acute saline loading before and after sodium repletion does not influence circulating levels of these compounds. These findings suggest that, at least in humans, adrenals are not the main source of endogenous digitalis-like factor(s) with polarity similar to (or less than) that of ouabain, and that plasma volume expansion may be not a sufficient stimulus for the release of this factor(s).

Adrenal Glands↗
PubMed1998

Relationship between cell counts in bovine milk and the presence of mastitis pathogens (yeasts and bacteria).

Bovine mastitis is an economically important disease in dairy industry and a variety of pathogen microorganisms are involved. The AA carried out a study to investigate the prevalence of yeasts and bacteria in milk samples (794) from dairy cows of Umbria (Central Italy), belonging to 19 herds, and the relationship between cell counts in bovine milk and the presence of these pathogens. 29.7% milk samples were positive for pathogen microorganisms, of those 4.9% were positive for yeasts and bacteria, 4.4% for yeasts and 20.4% for bacteria. The species of yeasts and bacteria most frequently encountered were Trichosporon capitatum (31.2%), T. beigelii (18.72%) and Candida albicans (12.48%), C. guillermondii (12.48%), C. tropicalis (12.48%); with regard to bacteria were Staphylococcus aureus (34.3%) and S. albo (19.8%). The presence of yeasts and bacteria in milk samples are correlated to an increase of somatic cell counts even if with different degree. Epidemiological and sanitary correlation were carried out.

Animals↗
PubMed1998

Epidemiological aspects of dermatophyte infections in horses and cattle.

Ringworm infections in the principal domestic animals are a major public and veterinary health problem. The aetiology, epidemiology and symptomatology of these mycoses are quite heterogeneous and complex. In this context, the AA carried out an epidemiological study to investigate the prevalence of dermatophytes in two different animal species, horses (n = 200) belonging to 10 private stables and cattle (n = 1900) belonging to farms with different breeding purposes and management. With regard to horses the results showed a positive level of 9% and Trichophyton equinum was the major organism isolated. The results concerning the cattle showed positive values that varied both in relation to the type of animals and their management as well as to the productive objectives: 19% in intensive beef breeding, 4.5% in intensive dairy farms (the aetiologic agent isolated in both types of farms was Trichophyton verrucosum) and 8% in traditional-type farms (the species of fungi isolated were T. verrucosum and Trichophyton mentagrophytes). The results are discussed both in clinical and in hygiene and management terms.

Animals↗
PubMed1998

Occurrence of fusaproliferin and beauvericin in Fusarium-contaminated livestock feed in Iowa.

Fusarium fungal contaminants and related mycotoxins were investigated in eight maize feed samples submitted to the Iowa State University Veterinary Diagnostic Laboratory. Fusarium moniliforme, F. proliferatum, and F. subglutinans were isolated from seven, eight, and five samples, respectively. These strains belonged to mating populations A, D, and E of the teleomorph Gibberella fujikuroi. Fusaproliferin was detected at concentrations of 0.1 to 30 microg/g in four samples, and beauvericin was detected (0.1 to 3.0 microg/g) in five samples. Fumonisins were detected in all eight samples (1.1 to 14 microg/g). Ten of 11 strains of F. proliferatum and all 12 strains of F. subglutinans isolated from the samples produced fusaproliferin in culture on whole maize kernels (4 to 350 and 100 to 1,000 microg/g, respectively). Nine F. proliferatum strains also produced beauvericin in culture (85 to 350 microg/g), but none of the F. subglutinans strains produced beauvericin. Fumonisin B1 was produced by all nine F. moniliforme strains (50 to 2,000 microg/g) and by 10 of the F. proliferatum strains (1,000 to 2,000 microg/g). This is the first report of the natural occurrence of fusaproliferin outside Italy and of the natural occurrence of beauvericin in North America.

Animal Feed↗
PubMed1998

Beauvericin production by Fusarium species.

Beauvericin is a cyclohexadepsipeptide mycotoxin which has insecticidal properties and which can induce apoptosis in mammalian cells. Beauvericin is produced by some entomo- and phytopathogenic Fusarium species (Fusarium proliferatum, F. semitectum, and F. subglutinans) and occurs naturally on corn and corn-based foods and feeds infected by Fusarium spp. We tested 94 Fusarium isolates belonging to 25 taxa, 21 in 6 of the 12 sections of the Fusarium genus and 4 that have been described recently, for the ability to produce beauvericin. Beauvericin was produced by the following species (with the number of toxigenic strains compared with the number of tested strains given in parentheses): Fusarium acuminatum var. acuminatum (1 of 4), Fusarium acuminatum var. armeniacum (1 of 3), F. anthophilum (1 of 2), F. avenaceum (1 of 6), F. beomiforme (1 of 1), F. dlamini (2 of 2), F. equiseti (2 of 3), F. longipes (1 of 2), F. nygamai (2 of 2), F. oxysporum (4 of 7), F. poae (4 of 4), F. sambucinum (12 of 14), and F. subglutinans (3 of 3). These results indicate that beauvericin is produced by many species in the genus Fusarium and that it may be a contaminant of cereals other than maize.

Anti-Bacterial Agents↗
PubMed1998

Use of the somatostatin analogue octreotide to localise and manage somatostatin-producing tumours.

BACKGROUND: Somatostatin receptor scintigraphy (SRS) and octreotide therapy have both changed the management of gastroenteropancreatic endocrine tumours, but very few data are available on the use of SRS and octreotide to visualise and treat somatostatinomas. METHOD: The results of SRS and octreotide treatment in three somatostatinoma patients were examined. RESULTS: SRS was able to detect extensive hepatic involvement in patient 1, one hepatic and one pancreatic lesion in patient 2, and one hepatic lesion in patient 3. Octreotide therapy (0.5 mg/day subcutaneously) was effective in decreasing plasma levels of somatostatin in all three patients. Symptoms (diabetes and diarrhoea) were greatly improved in the two patients with "somatostatinoma syndrome". CONCLUSION: The study shows that somatostatinoma, like most other gastroenteropancreatic endocrine tumours, possesses functioning somatostatin receptors.

Aged↗
PubMed1998

Structural and functional analysis of cyclin-dependent kinase inhibitor genes (CDKN2A, CDKN2B, and CDKN2C) in neuroblastoma.

The status of the CDKN2A gene family, including CDKN2A, CDKN2B, and CDKN2C, was investigated in 24 cases of neuroblastoma. These genes were selected on the basis of 1) high incidence of their inactivation in several human cancers and 2) their localization on chromosomal regions (9p and 1p) frequently rearranged in neuroblastomas. Detailed molecular analyses indicated the absence of homozygous deletions and point mutations involving these genes in all investigated tumor samples. However, when loss of heterozygostity for chromosome 9p21 (the region where CDKN2A and CDKN2B are localized) was investigated, 16% of cases showed abnormalities in an area telomeric to the CDKN2A locus. To study transcriptional silencing of the CDKN2A gene, the methylation status of exon 1 was examined. In about 35% of cases, a partial methylation was evidenced. Analysis of the CDKN2A mRNA expression, however, did not show any relationship between methylation status and gene transcription. Finally, expression of the CDKN2B gene was demonstrated in all stage IV neuroblastomas, whereas none of stage I tumors expressed this gene. This finding suggests the occurrence of a correlation between CDKN2B transcription and tumor phenotype.

Brain Neoplasms↗
PubMed1998

[Surgical reconstruction of the external nose: personal experience].

Because of the ensuring malformations, most often vascular in nature, malignant tumors of the nasal pyramid often require partial or total exeresis of the nasal structures. These tumors are most commonly basal cell carcinoma (85-90%) and squamous cell carcinoma (7-8%). A recent epidemiological survey performed in Italy showed that, in this country, such carcinomas account for approximately 13% of all malignant cutaneous neoplasms of the head and neck region. This work presents the author's personal experience in 8 cases of partial, subtotal and total reconstruction of the nose, performed over 5 years of clinical activity. The cases include 8 patients (4 males and 4 females, age range 48-95 years, mean age 77.3 years): 7 cases of malignant cutaneous nasal tumors (5 basal cell, 1 squamous cell and 1 basal-squamous cell carcinoma) and 1 case of iatrogeneous perforation through the entire thickness of the right nasal wall, approximately 7-8 mm in diameter, the outcome of sclerotizing treatments initiated 30 years before for angioma. On the whole, including the case of iatrogeneous nasal perforation the following procedures were used: 7 frontal fascio-cutaneous flaps and 1 nasal-genienic flap associated with a median of upper lip muscle. As regards the frontal flaps, in 5 cases a variation was used where the inset base was set more medially and with dimensions different from up-and-down Converse flaps. In 2 other cases a median frontal flap was used. Except for one case of partial necrosis of the flap, healed by subsequent surgery, complications were not particularly important from the clinical point of view and occurred in the broadest exeresis, where reconstruction of the structures adjacent to the nose and the mucosa lining proved necessary. On the whole, considering the initial stages of the lesions and the often advanced age of the patients, the surgical treatment gave good results from the oncological, aesthetic and functional points of view.

Aged↗
PubMed1997

Frequency of pheochromocytoma in adrenal incidentalomas and utility of the glucagon test for the diagnosis.

To investigate the frequency of pheochromocytoma in patients with incidentally discovered adrenal masses (incidentalomas) and to evaluate the sensitivity, specificity and diagnostic accuracy of the Glucagon test in comparison with resting plasma catecholamines, 89 patients with adrenal incidentalomas (age range 23-80 yr; 41 males and 48 females) were studied. Fifty-seven patients were normotensive (SBP 130+/-1.8 mmHg; DBP 80+/-0.7 mmHg, mean+/-SE) and 32 had stable hypertension (SBP 155+/-3.3 mmHg, DBP 93+/-1.4 mmHg): no patient complained of typical signs or symptoms of pheochromocytoma. Resting plasma samples for noradrenaline and adrenaline determination and, at appropriate intervals, the Glucagon test (1 mg i.v.), were performed in all subjects. Diagnosis of pheochromocytoma was made on the basis of humoral evaluations and/or surgical intervention in 6 patients (6.7%), of whom 3 hypertensives and 3 normotensives. Resting plasma catecholamines revealed 5 out of 6 patients with pheochromocytoma: in 3 cases both catecholamines were above the normal range, in 1 only adrenaline was elevated and in 1 case only noradrenaline. Similarily, the glucagon test identified 5/6 pheochromocytomas: in 3 patients the response was abnormal for both catecholamines, in 1 only for adrenaline and in 1 case only for noradrenaline. The sensitivity, specificity, and diagnostic accuracy of resting plasma catecholamines and of the glucagon test were comparable: 83.3%, 96.3%, and 95.5%, respectively. In conclusion, the frequency of pheochromocytoma in adrenal incidentalomas is not negligible, and since the diagnostic accuracy of the Glucagon test is the same of that of resting plasma catecholamines, the former does not appear to offer additional advantages in the diagnosis of incidentally discovered pheochromocytomas.

Adrenal Gland Neoplasms↗
PubMed1997

Frequent clonal loss of heterozygosity (LOH) in the chromosomal region 1p32 occurs in childhood T cell acute lymphoblastic leukemia (T-ALL) carrying rearrangements of the TAL1 gene.

Deletions and chromosomal translocations involving the 1p32 region, are frequently observed in T cell acute lymphoblastic leukemia (T-ALL). One of the most common genetic changes is the breakage of the TAL1 gene, which was originally described to be involved in the T-ALL carrying the t(1;14)(p32;q11) translocation. Site-specific deletions in the TAL1 gene are reported to occur in 12-26% of T-ALL with apparently normal karyotype. In order to investigate the presence of other subkaryotypic abnormalities involving the 1p32 chromosomal region, where TAL1 gene is mapped, we assessed losses of heterozygosity (LOH) for microsatellite markers, in a series of 22 children with T-ALL. Microsatellite polymorphic markers flanking the TAL1 gene (D1S211, D1S197, D1S200 and D1S220) were analyzed to detect LOH. Eight patients displayed LOH for at least one of the markers, suggesting the existence of hot spot regions at the short arm of chromosome 1. Two out of 11 with no molecular evidences of TAL1 gene involvement, compared to six out of 11 in the group of TAL1 rearranged gene, showed LOH at 1p32. TAL1 gene rearrangements and clonal LOH may represent two independent events, but could be related to the same causes. For the first time this study provides evidences that LOH at 1p32 region, occurs in T-ALL in the same region known to be involved in chromosomal deletions and translocations. LOH mapping may help to define the location of a new putative tumor-suppressor gene implicated in the transformation and progression of children T-ALL.

Adolescent↗
PubMed1997

Alteration of cytochrome P-450 isozymes by captopril and idrapril in hepatic and renal microsomes of normotensive and spontaneously hypertensive rats.

To examine the effects of angiotensin-converting enzyme (ACE)inhibitors such as captopril and idrapril on the P-450 system, these compounds were administered 100 mg/kg i.p. for 4 days to spontaneously hypertensive (SHRs) and normotensive Wistar-Kyoto (WKY) and Sprague-Dawley (SD) rats; thereafter, the principal hepatic and renal microsomal monooxygenase activities were determined. In all the rat strains used, both captopril and idrapril decreased only the P-450 2C11, (as determined by immunoblotting) and its linked activities such as 16alpha-, 2alpha- and 17-testosterone hydroxylases. These changes were accompanied by a significant decrease of blood testosterone levels both in normotensive and, more markedly, in hypertensive rats and by a reduction of systolic blood pressure, but only in SHRs. Only in SHRs as well, the renal immunodetectable P-450 4A content and the P-450 4A-dependent activities, such as the (omega)-lauric acid hydroxylase, diminished after captopril or idrapril treatment. These data suggest that the decrease of increased blood pressure in hypertensive SHRs by the ACE inhibitors may be linked to the downregulation of the circulating testosterone level, the renal P-450 4A expression, and the related formation of the potent vasoconstrictor (omega)-hydroxy arachidonic acid.

Angiotensin-Converting Enzyme Inhibitors↗