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Biomedical subjects

L Martini

Publications and source records attributed to L Martini.

At least 199 records · Page 11Linked to original sources
PubMed1979

Adrenergic inputs to the amygdala and the control of gonadotrophin release.

Drugs able to mimic or to antagonize the action of catecholamines have been implanted bilaterally into the basomedial region of the amygdala of adult castrated female rats. The animals were killed at different intervals after the implantation of the different drugs, and serum levels of LH and FSH were measured by radioimmunoassay. The results have shown that the intra-amygdalar implantation of the alpha-adrenergic blocker phenoxybenzamine induces a significant increase of the release both of LH and FSH. The implantation of the beta-adrenergic blocker propranolol brings about a rise of LH only. The dopamine receptor blocker pimozide stimulates the release of LH and exerts a biphasic effect (stimulation followed by inhibition) of FSH secretion. The alpha-receptor stimulant clonidine and the dopaminergic drug 2-Br-alpha-ergocryptine were without significant effects. From these observations it is suggested that the adrenergic signals reaching the basomedial area of the amygdala (possibly from the brain stem) may be involved in the modulation of gonadotrophin secretion.

Adrenergic Fibers↗
PubMed1978

Effect of neurotensin on glucose and insulin portal blood levels in hyperglycemic rats.

A new multiple sampling technique for obtaining blood from the portal vein has been used to investigate the effects of neurotensin on insulin and glucose portal blood levels in rats rendered hyperglycemic by a constant glucose infusion. The peptide has been first injected acutely (2 microgram/rat iv), and then constantly infused (0.5 microgram/min for 55 min). The preliminary results indicate that no effect of the acute injection could be observed, but hyperglycemia and hyperinsulinemia were induced by the constant infusion of the peptide. It is suggested that neurotensin may stimulate the release of insulin probably through a direct mechanism.

Animals↗
PubMed1978

Effects of prolactin on LH release in male rats.

Normal and castrated male rats were injected subcutaneously (s.c.) with a homologous preparation of prolactin (Prl) for 4 1/2 days, and serum levels of LH and FSH were measured at the end of the treatment. LH was undetectable in normal animals, injected either with Prl or with the vehicle. The treatment produced a significant reduction of the levels of LH in the castrated animals. No effect on FSH levels could be observed in either the normal or the castrated animals. The only relevant autopsy finding was a reduction of pituitary weight in normal animals treated with Prl. No effect on the weight of the testes or of the sex accessories was observed. It is suggested that Prl may directly interfere with the central mechanisms which control LH secretion.

Animals↗
PubMed1978

Effect of pentobarbital on serum levels of LH, FSH and prolactin in long-term ovariectomized rats.

The intraperitoneal (i.p.) administration of sodium pentobarbital (30 mg/kg) to long-term ovariectomized adult rats results in a prolonged depression of serum LH levels and in a biphasic decrease of serum prolactin (Prl) titers, but does not modify serum levels of FSH. Consequently, caution should be used when interpretating neuroendocrine results obtained in animals submitted to pentobarbital anesthesia.

Animals↗
PubMed1978

Gamma-amino-beta-hydroxy butyric acid stimulates prolactin and growth hormone release in normal women.

The influence of gamma-amino-beta-hydroxy butyric acid (GABOB) treatment on pituitary function has been investigated in this study. Different doses (50 x 100 mg) of GABOB were iv injected into three and six normal women, respectively. PRL and GH plasma levels were measured before and after the injection. The treatment with 150 mg GABOB, performed in another two normal women, was interrupted because of side-effects (loss of consciousness etc.) due to the treatment. The treatment with 50 mg GABOB did not induce significant variations of the two hormones; however, significant increases of PRL (P less than 0.05) and GH (P less than 0.01) plasma levels were observed after injection with 100 mg GABOB. The present data suggest that gamma-amino butyric acid (GABA) itself of GABAergic drugs might play an important role in the control of hypothalamic-pituitary function.

Adolescent↗