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Biomedical subjects

D Schiavone

Publications and source records attributed to D Schiavone.

At least 19 recordsLinked to original sources
PubMed2004

A nosocomial outbreak of Serratia marcescens producing inducible Amp C-type beta-lactamase enzyme and carrying antimicrobial resistance genes within a class 1 integron.

We investigated an outbreak of Serratia marcescens in the adult intensive care unit of the University Hospital of Napoli. The outbreak involved 13 cases of infection by S. marcescens over a nine-month period and was caused by a single pulsed-field gel electrophoresis clone. The epidemic strain was multiply antibiotic resistant, producing an inducible Amp C-type beta-lactamase enzyme and carrying the trimethoprim-resistance gene and the adenyltransferase gene, which confers resistance to streptomycin and spectinomycin, within a class 1 integron. Antimicrobial therapy with beta-lactams was associated with S. marcescens acquisition in the intensive care unit.

Adult↗
PubMed2001

Angiotensin-converting enzyme and angiotensinogen gene polymorphisms are non-randomly distributed in oral contraceptive-induced hypertension.

OBJECTIVES AND METHODS: Oral contraceptives (OC) usage increases serum angiotensinogen levels to three to five times normal and about 5% of these women develop arterial hypertension. The genetic contribution to this susceptibility to OC-induced hypertension is poorly understood. We have analyzed the genotypes of 149 hypertensive and 101 normotensive women using oral contraceptives, for three genetic polymorphisms in genes of the renin-angiotensin system: an insertion/deletion (I/ D) in the angiotensin converting enzyme (ACE) gene, the T235M polymorphism of the angiotensinogen gene (AGT) and a point mutation in its promoter. RESULTS: After cessation of oral contraception the mean arterial pressures of the hypertensive women were separable into two non-overlapping groups; 88 of the women remained hypertensive and 61 returned to normal blood pressure. Both groups of hypertensive women had a similarly higher frequency of hypertensive relatives than the normotensive women, but were otherwise similar. The 235T allele of AGT was significantly increased in frequency in the 61 oral contraceptive-inducible hypertensive women compared with the controls and the 88 women that remained hypertensive. The ACE I/D genotypes were similarly distributed within the three groups of women, but were distinctly non-random in the oral contraceptive-induced hypertensive women when they were also classified by AGT genotype. CONCLUSION: This statistical interaction of genotype frequencies suggests that the genetic basis of susceptibility to OC-induced hypertension is complex.

Adult↗
PubMed2001

Alpha1-adrenergic receptor subtypes in peripheral blood lymphocytes of essential hypertensives.

OBJECTIVE: The expression of alpha1-adrenergic receptor subtypes in peripheral blood lymphocytes was investigated in 28 essential hypertensive patients as well as in the peripheral blood lymphocytes and aorta of spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats. METHODS: Alpha1-adrenergic receptors were quantified by radioligand binding assays, employing [3H]-prazosin as the radioligand in association with compounds displaying different degrees of selectivity for alpha1A-, alpha1B- and alpha1D-adrenergic receptor subtypes. RESULTS: The affinity of [3H]-prazosin binding was similar in peripheral blood lymphocytes of different stage essential hypertensive and normotensive subjects or of SHR and age-matched normotensive WKY rats as well as in the aortas of SHR and WKY rats. The radioligand binding assay revealed no change in the expression of alpha1-adrenergic receptors in peripheral blood lymphocytes of essential hypertensives compared with normotensive subjects; a moderate decrease of alpha1B-adrenergic receptors and an increase of alpha1D-adrenergic receptors. The relative densities of the alpha1-adrenergic receptor subtypes were similar in the three groups of essential hypertensives. In peripheral blood lymphocytes and in aorta of SHR, [3H]-prazosin binding was significantly reduced compared with normotensive WKY rats. The expression of alpha1-adrenergic receptor subtypes in peripheral blood lymphocytes of SHR was similar to that found in peripheral blood lymphocytes of essential hypertensives. CONCLUSIONS: Changes of lymphocyte alpha1-adrenergic receptor subtypes in essential hypertensives are similar to those observed in lymphocytes and vascular tissues of animal models of hypertension. This suggests that assays of lymphocyte alpha1-adrenergic receptors may represent an indirect marker of their involvement in essential hypertension.

Adult↗
PubMed2001

[Histopathologic risk factors in patients with non-seminomatous germ tumors of the testis in clinical stage 1. Retrospective study of 75 patients].

OBJECTIVES: This retrospective study was performed to evaluate histopathologic prognostic risk factors in 75 patients on clinical stage 1 nonseminomatous germ cell cancer of the testis (NSGCTT). METHODS: From September 1976 to February 2000 we operated on 75 patients for NSGCTT on clinical stage 1 disease. Average age was 29.5 years (range 16-71). After orchiectomy, therapeutic options included retroperitoneal lymph node dissection (RLND) for 44 patients (58.6%), surveillance for 26 (34.6%) and neoadjuvant chemotherapy for 5 (6.6%). Testis primary tumor samples were assessed for studying prognostic risk factors that included vascular and/or lymphatic invasion (IV/IL+), percentage of embryonal carcinoma (%EC) and absence of yolk sac tumor (YS-). RESULTS: All patients were alive and disease-free. The average age follow-up was 84.5 months (range 1-254). Relapses occurred in 11 (14.6%) patients after an average follow-up of 9.09 months (range 3-24). Prognostic risk factors were detected as follows: IV/IL+ in 17 cases (22.7%), (50-80%) EC in 23 (30.6%), CE% > 80 in 23 (30.6%), YS- in 55 (72%). In 8 (10.6%) patients there was not any prognostic risk factor. Disease relapse related to prognostic risk factors was detected as follows: 18.1% for VI/LI, 90.9% for EC% > 50 (27.2% for 50-80% EC and 63.6% for CE% > 80) and 90.9% for YS-. Relapsing rates between patients with EC% > 80 and 50-80% EC resulted statistically significant (p = 0.02, odds ratio = 12.25). Relapsing rates between patients on surveillance and those who underwent RLND was next to be significant (p = 0.05, odds ratio 3.68). CONCLUSIONS: EC% > 80 is a prognostic risk factor for disease relapse in patients with clinical stage 1 NSGCT who are selected in a high risk group requiring RPLND or neoadjuvant chemotherapy as therapeutical option.

Adolescent↗
PubMed2000

General state of health and psychological well-being in patients after surgery for urological malignant neoplasms.

OBJECTIVE: To evaluate the general state of health and the psychological well-being in a group of 155 patients after surgery for urological malignant neoplasms. MATERIALS AND METHODS: Surgery was performed in 55 patients for renal cell carcinoma, in 54 for invasive bladder carcinoma, in 30 for adenocarcinoma of the prostate, and in 16 for squamous penile carcinoma. All patients were invited to self-compile the General Health Questionnaire (GHQ) - 12 items according to Goldberg and the Hospital Anxiety and Depression Scale. Results were compared with those in a group of patients who underwent retropubic prostatectomy for benign prostatic hyperplasia. RESULTS AND CONCLUSION: The general state of health was significantly more impaired in neoplastic patients than in the control group. Levels of anxiety were significantly higher but depression levels were similar in both groups. As far as the type of tumor is concerned, patients who underwent radical cystectomy for bladder carcinoma and those treated with partial penectomy for squamous penile carcinoma showed a significant impairment of the general state of health compared with controls. Higher levels of anxiety were observed in patients who underwent ileal conduit after radical cystectomy, in those treated with radical prostatectomy for prostate cancer and in those who underwent partial penectomy. Significantly higher levels of depression than in the control group were observed only in patients with ileal conduit.

Adaptation, Psychological↗
PubMed2000

CYP11B2 gene polymorphisms in idiopathic hyperaldosteronism.

Primary aldosteronism is characterized by autonomous production of aldosterone and arterial hypertension, and it occurs in 2 principal forms: aldosterone-producing adenoma (APA) and idiopathic hyperaldosteronism (IHA). APA can be cured through removal of the adenoma, whereas IHA leads to hypertension that must be treated with medication. The origin of the autonomous aldosterone production in IHA is poorly understood, but genetic factors may contribute to its cause. To test the hypothesis that variants of the aldosterone synthase gene may contribute to susceptibility to IHA, we compared genotypes at 3 polymorphic sites in the CYP11B2 gene in patients with IHA (n=90) with those found in patients with APA (n=38), in patients with essential hypertension (n=72), and in normotensive individuals (n=102). We observed significant linkage disequilibrium among the 3 polymorphisms with 2 frequent haplotypes in all groups studied. One haplotype (C2R) was found to be increased in frequency in the IHA group (47%) compared with the other groups, which had a similar haplotype frequency (36%). The 3 polymorphisms studied have been implicated in either essential hypertension or excess aldosterone production in previous studies. Because of the strong linkage disequilibrium, the observed results could be due to the action of any 1 of the 3 alleles or to another allele in linkage disequilibrium with them. Our results suggest that variations in the CYP11B2 gene may contribute to dysregulation of aldosterone synthesis and lead to susceptibility to IHA.

Alleles↗
PubMed2000

Detection of bladder cancer by semi-automated microsatellite analysis of urine sediment.

Patients with transitional-cell carcinoma (TCC) require careful follow-up due to the high risk of recurrence. Cystoscopy and biopsy are reliable but invasive, while urine cytology is plagued by low sensitivity. It has recently been shown that allelic abnormalities detected by microsatellite analysis of DNA extracted from urine can be used to diagnose TCC with high reliability. As this analysis by classic techniques is unfeasible in a clinical setting, we performed a pilot study to determine the possibility of applying quick DNA extraction methods with laser detection and computer-based analysis of 15 fluorescently labeled PCR amplified microsatellites to detect molecular anomalies in urine sediment in 25 TCC follow-up patients. Of the eighteen cases with recurrent TCC, 14 (78%) were positive by the molecular test whereas only eight (44%) were detected by cytology. Of the seven patients with negative cystoscopy, one resulted positive by the molecular test and had recurrent TCC six-months later. Thus, this microsatellite analysis correctly predicted the clinical diagnosis in 84% (21/25) of cases, compared to 60% by cytology. The application of these semi-automated procedures allows the analysis of 18 samples with 15 markers in one day, encouraging a more expedient introduction into routine clinical use.

Aged↗
PubMed1999

Relationship between birth weight and blood pressure in adolescence.

BACKGROUND: Several studies have found a relation ship between small size at birth and high blood pressure (HBP). However, this association has not been fully evaluated in adolescence. The aim of the present study was to evaluate the relation of birth weight (BW) to BP in adolescence, controlling for factors related to BP, to extrauterine environment, and to maternal risk of fetal distress. METHODS: In 1310 adolescents (ages 12-14 years), randomly selected from Turin school children, we evaluated BP, heart rate (HR), weight, height, familial risk of hypertension, parental cultural level, BW, and maternal history of diseases during pregnancy. The BW-BP association was tested by using multiple regression analysis and adjusting for the other variables mentioned above. The same analysis was done for the subgroup at high risk of fetal distress. RESULTS: The association between BW and BP was negative but weak when we adjusted for all confounders (= -0.07 in males; = -0.27 in females). The association was negative and became stronger after the inclusion of all confounders, particularly HR (= -3.92), in the group of children at high risk of fetal distress. CONCLUSIONS: Intrauterine environment, as reflected by BW, has little effect on BP in early adolescence without concomitant maternal diseases or environmental conditions leading to severe placental hypoperfusion.

Adolescent↗
PubMed1999

Surgical treatment of penile carcinoma: our experience from 1976 to 1997.

OBJECTIVE: The purpose of this work is to evaluate our experience with the surgical treatment of penile squamous carcinoma, analyzing the therapeutic results in terms of local recurrence rates, survival and mortality rates. MATERIAL AND METHODS: From 1976 to 1997, 47 patients were treated at our institution for carcinoma of penis. Treatment of primary tumor was conservative in 8 patients (17%). Partial penectomy was performed in 30 patients (63.8%); total penectomy in 5 (10.7%) and emasculation in 4 (8.5%). Pathological stage was pTis in 2 cases (4.2%), pT1 in 20 (42.6%), pT2 in 21 (44. 7%) and pT3 in 4 (8.5%). The tumor was clinically overstaged in 13 patients (27.7%) and understaged in 4 (8.5%). Bilateral inguinal lymphadenectomy was performed only in 4 patients clinically N+ (pN2) and in 3 clinically N0 (pN0). RESULTS: Local recurrence rate was 43% in the patients with pT1 stage tumor treated conservatively. No local recurrence was observed after penectomy. 19 patients (40.4%) are alive and disease-free; 17 patients (36.2%) died of the tumor and 11 patients (23.4%) died of other causes but disease-free. Mean follow-up is 69.43 months. The overall 5-year survival rate was 34%. CONCLUSION: Partial penectomy gives better results than conservative treatment in the local management of the T1 stage tumor. Survival and mortality rates are related to both pathological and histological stages. The high mortality rate observed in the pT2 stage tumors in our experience might be related to the fact that in this stage an inguinal lymphadenectomy was not performed as a rule.

Carcinoma, Squamous Cell↗
PubMed1999

alpha1-adrenergic receptor subtypes in human peripheral blood lymphocytes.

We investigated the expression of alpha1-adrenergic receptor subtypes in intact human peripheral blood lymphocytes using reverse transcription-polymerase chain reaction (RT-PCR) and radioligand binding assay techniques combined with antibodies against the three subtypes of alpha1-adrenergic receptors (alpha1A, alpha1B, and alpha1D). RT-PCR amplified in peripheral blood lymphocytes a 348-bp alpha1A-adrenergic receptor fragment, a 689-bp alpha1B-adrenergic receptor fragment, and a 540-bp alpha1D-adrenergic receptor fragment. Radioligand binding assay with [3H]prazosin as radioligand revealed a high-affinity binding with a dissociation constant value of 0. 65+/-0.05 nmol/L and a maximum density of binding sites of 175. 3+/-20.5 fmol/10(6) cells. The pharmacological profile of [3H]prazosin binding to human peripheral blood lymphocytes was consistent with the labeling of alpha1-adrenergic receptors. Antibodies against alpha1A-, alpha1B-, and alpha1D-receptor subtypes decreased [3H]prazosin binding to a different extent. This indicates that human peripheral blood lymphocytes express the three alpha1-adrenergic receptor subtypes. Of the three different alpha1-adrenergic receptor subtypes, the alpha1B is the most represented and the alpha1D, the least. Future studies should clarify the functional relevance of alpha1-adrenergic receptors expressed by peripheral blood lymphocytes. The identification of these sites may represent a step for evaluating whether they represent a marker of alpha1-adrenergic receptors in cardiovascular disorders or for assessing responses to drug treatment on these receptors.

Adrenergic alpha-1 Receptor Antagonists↗
PubMed1999

Vasoactive hormones induce nitric oxide synthase mRNA expression and nitric oxide production in human endothelial cells and monocytes.

Isoform-2 nitric oxide synthase (NOS-2) mRNA expression and nitric oxide (NO) production are induced in endothelial cells and monocytes by cytokines such as gammaIFN and LPS. We evaluated NOS-2 and isoform-3 NOS (NOS-3) mRNA expression and NO production in human monocytes and human umbilical vein endothelial cells (HUVEC), under basal conditions and after incubation with physiologic concentrations of vasoactive hormones. NOS mRNA expression was detected by reverse transcription polymerase chain reaction (RT-PCR) and NO production by electronic paramagnetic resonance spectroscopy (EPR). We showed that NOS-2 mRNA expression and NO production were induced by stimulation with epinephrine, dopamine, endothelin-1, and angiotensin II, both in monocytes and HUVEC. NOS-3 mRNA expression and NO production were detected under basal conditions in monocytes and HUVEC and were not modified by the presence of vasoactive hormones. Human endothelial cells and monocytes express the NOS-2 and NOS-3 mRNA and the inducible NOS-2 mRNA expression increases after vasoactive hormone stimulation.

Adult↗
PubMed1999

[Comparison of the quality of life of patients treated by surgery or radiotherapy in epidermoid cancer of the penis].

OBJECTIVE: The purpose of our work is to examine how partially or totally radical surgery and radiotherapy can weigh on quality of life in patients with squamous carcinoma of the penis, considering whether quality of life can be a good criterion in treatment options. MATERIAL AND METHODS: We have interviewed 17 patients alive and disease-free (average follow-up 69.43 months) after surgical treatment or radiotherapy for cancer of the penis (emasculation, 2; total amputation of the penis, 2; partial penectomy, 11; radiotherapy, 2). Tests used: General Health Questionnaire (G.H.Q.-12 by D. Goldberg); Hospital Anxiety and Depression Scale (H.A.D.S.); Social Problem Questionnaire (S.P.Q.); Overall Sexual Functioning Questionnaire (O.S.F.Q); Family APGAR Questionnaire (F.A.Q.); Performance Status ECOG. RESULTS: Thirty-five per cent of the patients presented limitations in their state of health and social problems. Anxiety was evident in 29.5% of the patients and depression in 6%. The global sexual function was compromised in 76.5%. CONCLUSION: The profile of quality of life resulted compromised in the patients who had undergone radical surgical treatment. The sexual function was the most altered component. The impact of the pathology and its treatment on the other domains of quality of life proved less significant.

Adult↗
PubMed1998

Blood pressure and heart rate in young thalassemia major patients.

The analysis of blood pressure (BP) and heart rate (HR) variability is currently used to investigate the mechanisms responsible for cardiovascular control; therefore, we assessed whether an impairment of 24-h BP and HR profiles and sympathovagal interaction modulating cardiovascular function was present in patients with thalassemia major (TM) in preclinical phase of heart disease. Nine beta-thalassemic patients 18 years old without clinical signs of cardiac failure and 9 age- and sex-matched controls were studied. Twenty-four-hour-ambulatory BP and HR were measured using the SpaceLabs 90207 device. A truncated Fourier series with four harmonics was used to describe the diurnal blood pressure profile. Mean 24-h ambulatory systolic BP, diastolic BP, and mean arterial pressure were significantly lower in TM patients than in normal subjects (P < .05). A significantly higher nighttime HR value was found in TM patients (P < .05). More than 40% of the TM patients did not show a significant diurnal BP and HR rhythm. In TM patients, the overall amplitude of systolic BP, diastolic BP, and HR was significantly lower than in controls (P < .01). The night/day differences of systolic BP, diastolic BP, and HR were significantly lower in TM patients than in normals (P < .01). Furthermore, we performed power spectral analysis on short-term continuous finger BP and HR data in supine position and during passive head-up tilt. Total spectral power of systolic BP was significantly lower in patients than controls (P < .05). Low-frequency (LF) power of systolic BP and diastolic BP and LF/high-frequency (HF) ratio of HR were significantly lower during tilt in TM patients compared to controls (P < .05). High-frequency power of HR was significantly higher in patients than controls (P < .05). The baroreflex gain assessed by alpha-index was the same in supine position but was higher in TM patients during passive tilt (P < .05). An inverse relationship between LF/HF ratio of HR and hemoglobin levels in TM patients was found. Finally, plasma norepinephrine levels were significantly lower in thalassemics (P < .005). In young TM patients in a preclinical stage of heart disease, these findings demonstrated abnormal 24-h BP and HR rhythms and a decreased short-term variability of BP and HR, in particular in the LF range, showing a diminished sympathetic activity.

Adolescent↗
PubMed1998

Evaluation of serotonin levels in human aqueous humor.

PURPOSE: Serotonin is biochemically present in the iris and ciliary body of animals and humans. Controversial findings are reported about the concentrations of serotonin in aqueous humor with respect to plasma in humans. The aim of this study was to evaluate the levels of serotonin both in aqueous humor and plasma in human subjects. METHODS: In 50 patients with glaucoma or cataract, plasma and aqueous humor serotonin levels were measured by HPLC with electrochemical detection. Serotonin plasma levels were also measured in 25 healthy subjects as controls. RESULTS: In all patients with cataract or glaucoma, the aqueous humor serotonin concentration is significantly lower than that in plasma [1.14+/-0.29 (SEM) vs. 5.33+/-1.03 ng/ml, p<0.01]. Furthermore, in the same patients and in 25 healthy controls, serotonin plasma levels were similar. CONCLUSION: Our study shows that serotonin is present in human aqueous humor and its concentration is 4 times lower than in plasma.

Adult↗
PubMed1997

Impaired cortisol binding to glucocorticoid receptors in hypertensive patients.

We compared glucocorticoid receptor binding characteristics and glucocorticoid responsiveness of human mononuclear leukocytes (HML) from hypertensive patients and matched normotensive volunteers. We also considered associations of these variables with plasma renin activity, aldosterone, cortisol, corticotropin, and electrolyte concentrations. We calculated binding affinity (Kd; nmol/L) and capacity (Bmax; sites/cell) for dexamethasone and cortisol from homologous and heterologous competition curves for specific [3H]dexamethasone binding sites on HML isolated from the blood of normotensive volunteers and subjects with essential hypertension. Glucocorticoid responsiveness of HML was evaluated as IC50 values (nmol/L) for dexamethasone and cortisol for the inhibition of lysozyme release. We measured plasma hormones by radioimmunoassay. Kd values (mean+/-SE) for cortisol in HML of hypertensive patients were higher than in control subjects (24.6+/-2.4 versus 17.5+/-1.7 nmol/L, P<.04). Binding capacity (4978+/-391 versus 4131+/-321 sites/cell), Kd values for dexamethasone (6.7+/-0.5 versus 5.7+/-0.3 nmol/L), and IC50 values for dexamethasone (3.4+/-0.3 versus 3.1+/-0.2 nmol/L) and cortisol (12.2+/-1.6 versus 9.5+/-0.3 nmol/L) were not significantly different. Patients with renin values less than 0.13 ng angiotensin I/L per second were markedly less sensitive to cortisol than those with higher values. Both Kd (30.3+/-2.5 versus 19.2+/-2.4 nmol/L) and IC50 values (15.5+/-1.8 versus 8.9+/-1.2 nmol/L) for cortisol were significantly higher in patients with lower renin values (P<.03). Other variables, including plasma hormone and electrolyte values and binding characteristics for dexamethasone, were not different. These data suggest that cortisol binding to glucocorticoid receptor is slightly impaired in patients with essential hypertension. In vivo, this could lead to inappropriate binding of cortisol to mineralocorticoid receptors. Hence, decreased sensitivity to cortisol is associated with renin suppression. This hypothesis is supported by evidence of hypertension and low renin activity, which others have described in patients with primary glucocorticoid resistance due to mutations of the glucocorticoid receptor.

Adult↗
PubMed1996

Weighted Fourier analysis of blood pressure curves after lisinopril versus atenolol administration in young hypertensives.

OBJECTIVE: To evaluate and compare the effects of lisinopril versus atenolol administration on the diurnal blood pressure profile and the nocturnal blood pressure fall in young mild-to-moderate essential hypertensives.METHODS: Thirty patients were studied. After a 2-week placebo run-in period, they were single-blind randomly assigned to receive 20 mg lisinopril or 100 mg atenolol. Using a SpaceLabs 90207 device, their ambulatory blood pressure was measured before and after 12 weeks of therapy. The readings were analysed using Fourer series with four harmonics. RESULTS: Lisinopril and atenolol administration significantly decreased office and ambulatory blood pressure values compared with the placebo period. The daily blood pressure curves obtained from Fourier analysis showed that the circadian rhythm was not altered by lisinopril and atenolol administration. From the night:day ratio for the nocturnal blood pressure fall, we found that atenolol administration minimized the average night-time blood pressure dip by increasing the number of non-dippers. In contrast, lisinopril administration did not modify the day-night difference, preserving the nocturnal blood pressure fall. CONCLUSION: Lisinopril and atenolol administration as a first-step treatment of young essential hypertensives produced comparable degrees of diurnal control of arterial pressure. The blood pressure fall at night in patients treated with atenolol was slightly less than that found with lisinopril treatment.

Journal Article↗
PubMed1995

Levels of plasma neuropeptide Y and other vasoactive substances during head-up tilt in normal and essential hypertensive subjects.

Neuropeptide Y, a potent vasoconstrictor peptide with 36 amino acid residues, is co-stored and released with catecholamines in sympathetic nerve endings. In this study responses in circulating neuropeptide Y induced by baroreceptor activation during change from the supine to the head-up position was measured in normal subjects and untreated essential hypertensives. Furthermore, the relationships with plasma catecholamines, endothelin-1, renin and serotonin were studied. No significant differences of plasma neuropeptide Y were found between normotensive and hypertensive subjects, before or after postural changes, and there was no correlation with a range of the vasoactive substances studied. Our results suggest that plasma neuropeptide Y does not increase with noradrenaline on sympathetic activation during postural stress both in normals and in hypertensive subjects. In man, measurement of plasma neuropeptide Y during head-up tilt does not provide a useful estimation of sympathetic nervous activity.

Adult↗
PubMed1995

Dopamine D5 receptor expression is unchanged in peripheral blood lymphocytes in essential hypertension.

The present study was designed to investigate possible changes in the expression of lymphocyte dopamine receptor in essential hypertension. The expression of dopamine D5 receptor was evaluated by radioligand binding techniques using [3H]-SCH 23390 as ligand. Plasma catecholamines, aldosterone levels and plasma renin activity were also measured. Eleven borderline hypertensive patients, 15 patient with the mild essential hypertension, 7 patients with moderate essential hypertension and 5 patients with severe essential hypertension were examined. Plasma catecholamine levels were assayed by high pressure liquid chromatography with electrochemical detection. Dopamine D5 receptor was measured by radioligand binding techniques. Plasma aldosterone levels and renin activity were determined by radio immunoassay. [3H]-SCH 23390 was specifically bound to human peripheral blood lymphocytes. The binding was time-, temperature- and concentration-dependent with a dissociation constant (Kd) value of 0.59 nM and a maximum density of binding sites (Bmax) of 223 pmol/10(6) cells. Dopamine competed with [3H]-SCH 23390 binding in the submicromolar range suggesting the labelling of a dopamine D5 receptor. No changes in the density of [3H]-SCH 23390 binding sites were observed in human peripheral blood lymphocytes between essential hypertensive patients and normotensive subjects. Also catecholamines, plasma renin activity and aldosterone levels were unchanged. In spite of the availability of a sensitive technique for measuring dopamine receptors in human peripheral lymphocytes, no change in their expression was noticeable in essential hypertension. This suggests that dopamine receptor analysis in essential hypertension is not a useful marker for investigating hypertension-dependent changes of the peripheral dopaminergic system.

Adult↗