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Biomedical subjects

C Barbieri

Publications and source records attributed to C Barbieri.

At least 91 records · Page 5Linked to original sources
PubMed1980

Metabolic effects of prazosin.

The effects of oral administration of 2 mg prazosin on several metabolic and endocrine variables were evaluated in 12 patients with hypertension (6 with normal and 6 with abnormal glucose tolerance). Prazosin was followed by a rise in plasma glucose and serum free fatty acids (FFA) in both normal and diabetic subjects; there was a trend upward in serum albumin (IRI), but growth hormone (GH), prolactin (PRL), and gastrin did not change. Although these results are in general agreement with metabolic effects of other alpha adrenergic blockers already reported, the rise in plasma glucose is at variance with studies performed with phentolamine.

Adrenergic alpha-Antagonists↗
PubMed1980

Growth hormone secretion in hypertensive patients: evidence for a derangement in central adrenergic function.

1. In an attempt to test the hypothesis of a derangement in central catecholaminergic function in hypertensive patients, the serum growth hormone and prolactin responses to the alpha-adrenergic agonist clonidine (0.15 mg infused intravenously) and to L-dopa administration (500 mg orally) were evaluated in 15 hypertensive and 15 normotensive subjects matched for sex, age and body weight. 2. Whereas L-dopa elicited a growth hormone response of similar magnitude in both groups, clonidine infusion induced a significant increase in serum growth hormone in normotensive, but not in hypertensive, subjects. 3. Prolactin levels were equally suppressed by L-dopa and did not change after clonidine in either group. 4. The present study adds neuroendocrine evidence to the concept of a derangement in central alpha-adrenergic function in human hypertension.

Adult↗
PubMed1980

Metabolic effects of chronic prazosin treatment.

The effects of chronic (3 mg/day for 1 week) administration of the vasodilator drug prazosin on several metabolic and endocrine variables were evaluated in 12 hypertensive patients, 6 with normal and 6 with abnormal oral glucose tolerance test (OGTT). After 1 week prazosin treatment there were no significant modifications in fasting plasma glucose, serum free fatty acids (FFA), cholesterol, triglycerides, insulin (IRI), growth hormone (GH), prolactin (PRL) and gastrin levels; oral glucose tolerance and IRI response to glucose were unchanged in normal subjects, while in chemical diabetics there was a significant improvement in glucose tolerance and a slight increse in IRI secretion. Therefore, the untoward metabolic effects of acute prazosin administration, i.e. increased plasma glucose and serum FFA, are not sustained during chronic treatment, which may even improve glucose metabolism in diabetic patients.

Adrenergic alpha-Antagonists↗
PubMed1980

Effect of four dopamine receptor antagonists on gastrin secretion in healthy subjects.

The effect of 1 week of oral treatment with four antidopaminergic drugs--metoclopramide, sulpiride, haloperidol, and pimozide--on fasting and meal-stimulated serum gastrin levels has been evaluated in healthy subjects. All of the four drugs significantly reduced the gastrin response to a meal, whereas basal concentration was unaffected. It is suggested that this action is mediated by central nervous system dopamine receptor blockade, which might act either via nervous or humoral mechanisms to inhibit gastrin release.

Adult↗
PubMed1980

Clonidine-induced hyperglycemia: evidence against a growth hormone-mediated effect.

The effects of acute clonidine infusion (0.15 mg over 10 min) on several endocrine and metabolic variables have been evaluated in 12 hypertensive patients and 12 normotensive controls. Plasma glucose increased significantly in comparison with a placebo study in both groups; serum growth hormone showed a significant increase in healthy subjects but did not rise in hypertensive patients; there was no correlation between the increments in plasma glucose and in serum growth hormone in the whole group of subjects; serum-free fatty acids, insulin, prolactin and plasma cortisol did not change in any group. These data, although not excluding a central site of the clonidine hyperglycemic action, contrast the view that it may depend on stimulation of growth hormone release.

Adult↗
PubMed1979

Improved oral glucose tolerance following antiserotonin treatment in patients with chemical diabetes.

The effects of short-term treatment with either placebo or two serotonin antagonists, cyproheptadine and metergoline, on oral glucose tolerance and insulin secretion have been evaluated in normal subjects and in patients with chemical diabetes. Placebo treatment was not associated with any significant change in the parameters examined. Glucose tolerance in chemical diabetics was significantly improved both after cyproheptadine and metergoline; fasting plasma glucose was also reduced by metergoline. Treatment with the latter drug was also associated with a significant decrease in incremental glucose area in healthy subjects, which was not affected by cyproheptadine. Basal and glucose-stimulated insulin secretion were not affected by either drug in any subjects. Cyproheptadine and metergoline improve glucose metabolism in chemical diabetes probably by reducing insulin resistance. This may depend either on decreased secretion of counter-regulatory hormones or on a direct pharmacological action of the drugs on glucose utilization, possibly mediated by their common antiserotoninergic properties.

Adult↗
PubMed1979

Prolactin release by intravenous cimetidine in man: evidence for a suprapituitary locus on action.

In an attempt to identify the sites at which cimetidine stimulates prolactin release, the drug was administered intravenously (6 mg/kg body weight) to healthy subjects under basal conditions, during dopamine infusion (1 microgram/Kg-min for 120 min) and after pretreatment with L-dopa plus carbidopa (250 plus 25 mg every 6 for 1 day). The serum prolactin response to cimetidine was abolished by dopamine infusion and almost completely suppressed by L-dopa plus carbidopa administration. These findings suggest that the drug acts on the central nervous system to stimulate prolactin release. Although the mechanism of this action is unclear, it does not seem to depend on an antidopaminergic effect and may be related to blackade of brain H2 histamine receptors.

Adult↗
PubMed1978

Disappearance of oxytocin-induced uterine tiredness by treatment with fructose-1,6-diphosphate. Experimental evidence.

Fructose-1,6-diphosphate (FDP) is able to abolish oxytocin induced spastic inertia in rat uterus. The clinical use of FDP is suggested by observation carried out on 30 deliveries with oxytocin induction. The FDP-treated patients (5 g of FDP in 50 ml of water by intravenous infusion) showed a statistically significant decrease of time elapsed between the beginning of uterine inertia and the recovery of uterine contractions (176 +/- 25.4 min) compared to controls (562 +/- 32.5 min).

Adolescent↗
PubMedDate not supplied

Stimulation of prolactin release by intravenous cimetidine: a dose-response study.

The PRL response to iv cimetidine was tested in 8 healthy males and 8 females at 4 different dose levels (0.75, 1.5, 3.0 and 6.0 mg/kg bw). Serum PRL levels were significantly increased in comparison with a placebo study by the second cimetidine dose in both sexes. The PRL response was significantly higher in females than in males at all but the lowest dose tested. A significant correlation between the cimetidine dose and the PRL response was observed. There was no significant modifications in serum GH, LH, FSH, IRI and glucose. Present findings demonstrate that the stimulation of PRL release by iv cimetidine is quite specific and dose-dependent.

Adult↗
PubMedDate not supplied

Endocrine and metabolic effects of labetalol in man.

The effects of intravenous infusion of the alpha- and beta-adrenoceptor blocking drug labetalol (100 mg over 10 min) on heart rate, blood pressure, and several endocrine and metabolic variables have been evaluated in 12 hypertensive patients (6 men and 6 women). Drug administration was associated with significant lowering of heart rate and systolic and diastolic blood pressure in comparison with a control study performed with saline infusion. Plasma glucose was significantly increased, while no changes were observed in serum-free fatty acids, insulin, C-peptide, and growth hormone levels. Serum prolactin concentration was significantly increased in the whole group, a marked rise occurred in females, while only a trend upward was observed in males. The acute lowering of blood pressure suggests a predominant activity on alpha-adrenoceptors following intravenous labetalol infusion, although the reduction in heart rate is consistent with the beta-adrenoceptor blocking effect of the drug. Although the reason for the increase in plasma glucose is not apparent, it might depend on the rise in norepinephrine levels observed after labetalol. Stimulation of prolactin release by intravenous labetalol is not easily attributable to interference with adrenergic receptors. The mechanism of this action of the drug is presently obscure, although a possible antidopaminergic activity of labetalol might be involved.

Adult↗
PubMedDate not supplied

Effects of advance care education in cardiovascular rehabilitation programs: a prospective randomized study.

PURPOSE: To determine the effect of advance care education provided to patients enrolled in cardiovascular rehabilitation (CVR) programs and assess patients' acceptance of the educational program. METHODS: In a multicenter, prospective, randomized study, the authors administered two questionnaires 6 months apart to 284 patients enrolled in 14 CVR programs in 11 states. An educational group (99 subjects) participated in educational programs related to advance care planning and received advance directive forms after completing the first questionnaires; 185 subjects served as controls. Primary outcomes were completion of patient-physician discussions of end-of-life issues and patient confidence that their end-of-life wishes were understood by their physicians. Secondary outcomes were completion of formal advance directives and patient acceptance of the educational program. RESULTS: Both the educational and control groups demonstrated a larger proportion of patients at the end of the study, compared with the amount at the beginning of the study, who had completed living wills, durable powers of attorney for healthcare, and discussions with their physicians about advance directives and life support care. These outcomes were not observed more commonly after the educational intervention. Neither groups gained confidence, however, that their physicians understood their end-of-life wishes. Only 8.6% of patients had a negative response to the educational program. CONCLUSIONS: Advance care education is well received by patients enrolled in CVR programs. Enrollment in CVR promotes advance care planning to a small but measurable degree CVR rehabilitation programs appear to be acceptable sites for advance care planning but further research is needed to develop effective educational interventions.

Adult↗