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Biomedical subjects

P Cianciosi

Publications and source records attributed to P Cianciosi.

7 recordsLinked to original sources

Effect of the 5-HT3 receptor antagonist ondansetron on plasma AVP secretion: a study in cancer patients.

The aim of the present study was to investigate the effects of a serotonin subtype 3 receptor antagonist, ondansetron, on arginine vasopressin secretion in humans. Plasma vasopressin concentrations were determined in 24 breast cancer patients undergoing adjuvant chemotherapy, before and after ondansetron intravenous (i.v.) administration. Ondansetron (8 mg i.v. at time 0 and 8 mg po at time 240 min) was administered alone in 12 patients and afterwards in combination with chemotherapy in all patients. No changes in hormone levels were found after ondansetron alone and in 17 patients who did not claim nausea and/or emesis after chemotherapy. In seven patients who experienced nausea and /or emesis, vasopressin levels significantly (P < 0.01) increased (from 6.3 +/- 0.9 ng/L in basal conditions to 15.1 +/- 3.3 ng/L at 10 h; P < 0.05 vs baseline). The results suggest the possibility that in humans, serotoninergic mechanisms, which modulate vasopressin secretion, may involve the activation of the serotonin receptors recognised by ondansetron.

Aged↗

Plasma beta-endorphin levels and glucose tolerance in patients with chronic renal failure.

In order to examine the role of endogenous opioid peptides on glucose metabolism in uraemic patients, plasma concentrations of beta-endorphin, glucose, insulin and C-peptide were determined before and during an oral glucose tolerance test (OGTT) in nine non-dialysed patients with chronic renal failure (CRF). The results are compared with those obtained in a group of age-matched normal subjects. In CRF patients, plasma beta-endorphin fasting values (16.0 +/- 1.9 pmol/l) were significantly higher than those of the controls (6.6 +/- 0.6 pmol/l) and significantly correlated with the degree of renal function impairment. After glucose load, plasma beta-endorphin in CRF patients tended to decline, whereas in normal subjects increased. The fasting and the mean OGTT plasma beta-endorphin values negatively correlated with insulin initial response to glucose, insulin and C-peptide mean OGTT values, but not with glucose OGTT mean values. Data indicate that chronic uraemia induces a significant increase in circulating plasma beta-endorphin levels, with a loss of opioid system responsiveness to glucose. The possibility that this hyper-endorphinism may have a biological importance at least as a contributory factor of impaired glucose tolerance in uraemia may be suggested.

Adult↗

The effects of sumatriptan on pituitary secretion in man.

Sumatriptan, a new antimigraine drug with high affinity and selectivity for certain 5-hydroxytryptamine (5-HT1D) receptor subtypes, was administered to 12 normal subjects, in order to investigate the effects of 5-HT receptor activation on anterior pituitary secretion. Sumatriptan increased plasma growth hormone (GH) levels from 2.5 +/- 0.5 mIU/l in basal conditions to 17.3 +/- 2.6 mIU/l 30 min after administration of the drug. After pre-treatment with cyproheptadine, an anti-serotoninergic drug known to inhibit GH secretion, the mean integrated sumatriptan-induced GH response decreased from 14.8 +/- 3.9 muI/l*hr to 3.7 +/- 1.7 mIU/l*hr. Sumatriptan administration did not have any effect on the secretion of the other anterior pituitary hormones. It is concluded that sumatriptan selectively increases GH secretion in man, but the exact nature of the receptors involved is not yet known.

Adult↗

Twenty-four-hour beta-endorphin secretory pattern in stroke patients.

BACKGROUND AND PURPOSE: Abnormalities of hypothalamo-pituitary-adrenocortical axis function have been observed frequently in stroke patients. The aim of this study was to investigate plasma beta-endorphin and cortisol 24-hour secretory patterns in patients early after stroke and in the convalescent period to evaluate a possible influence of brain damage on hormonal circadian pattern. METHODS: Patients (n = 15; age, 46 to 75 years) were evaluated in the first 24 hours and 10 days after hospital admission for ischemic cerebral stroke and compared with 15 age- and sex-matched normal subjects. Blood samples for beta-endorphin and cortisol determination were drawn every 4 hours from 8 AM to 8 PM and every 2 hours from midnight to 6 AM. RESULTS: Mean 24-hour beta-endorphin and cortisol levels, recorded in the acute phase, were significantly (P < .05) higher than those recorded in normal subjects; circadian rhythm was not demonstrable for either hormone. In the convalescent period, plasma cortisol 24-hour mean values and circadian rhythm returned to the normal range, whereas the plasma beta-endorphin 24-hour mean values and circadian rhythm did not. CONCLUSIONS: Cerebral stroke induces abnormalities of beta-endorphin and cortisol circadian secretion. Whereas cortisol abnormalities are transient, those of beta-endorphin last longer. The dissociation between beta-endorphin and cortisol 24-hour secretory patterns might potentially serve as a marker of psychoneurological abnormalities occurring after stroke.

Aged↗

Calcitonin and beta-endorphin secretion.

Calcitonin is a peptide hormone secreted by the C-cells of the thyroid gland. This hormone mainly acts in preventing bone resorption. Furthermore, calcitonin is involved in other biological actions, and in particular it is able to relieve pain independently of its peripheral effects on bone. Here, we examine the possible mechanisms of calcitonin-induced analgesia, with particular regard to the opioid system involvement. Several studies in animals and in humans demonstrate that calcitonin increases plasma beta-endorphin levels, acting at the hypothalamic and/or at the pituitary level, either directly or indirectly, through monoaminergic neurotransmitters. However, this calcitonin-induced beta-endorphin release has not always been observed. These different results are discussed, and a possible implication of sex and/or calcitonin dose employed has been examined. We conclude that the analgesic effects of calcitonin are multifactorial, and beta-endorphin plays its own specific role.

Analgesics↗

Sumatriptan does not affect vasopressin secretion in humans.

The aim of the study was to investigate the effects of a new serotoninergic drug, sumatriptan, on arginine vasopressin secretion in humans. Plasma vasopressin concentrations were determined in eight healthy volunteers, before and after administration of 6 mg of sumatriptan, or placebo. No changes in hormone levels were found after sumatriptan or placebo administration. The results suggest that in humans serotoninergic mechanisms, which modulate vasopressin secretion, do not involve the serotonin receptor activated by sumatriptan.

Adult↗