Effect of 5-Hydroxytryptophan on Prolactin and Growth Hormone Release in the Infant Rat: Evidence for Different Neurotransmitter Mediation

Cocchi, Daniela; Gil-Ad, Irit; Panerai, A; Locatelli, Vittorio; Ee, Müller

doi:10.1159/000122691

Cited by 26 publications

(9 citation statements)

References 28 publications

(36 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These results indicate that maternal ethanol ingestion does not alter the tryptaminergic control of GH secretion in the offspring. The reduced levels of serum GH seen in control animals after cyproheptadine are in agreement with previous findings where either this or other serotonin-block ing agents were used [2,15], Since both catecholaminergic and tryptaminergic sys tems exert control overGH secretion during the early neona tal period, animals were subjected to stressful stimuli which cause an increase in sympathetic neural tone. A previous study had shown that in 12-day-old rats, insulin hypogly cemia or cold exposure causes a reduction in plasma GH levels (6], In the present study, a lack of GH response to insulin and cold exposure in the pups exposed continuously to ethanol suggests a possibility that the developmental pattern of noradrenergic control of GH secretion is alteredy by perinatal ethanol exposure.…”

Section: Thadani Discussionsupporting

confidence: 90%

See 1 more Smart Citation

Effect of Maternal Ethanol Ingestion on Control of Growth Hormone Secretion by Biogenic Amines in Rat Offspring

Thadani¹

1984

Neuroendocrinology

View full text Add to dashboard Cite

Pregnant rats were kept on an ethanol-containing (6% w/v) liquid diet from the 13th day of gestation and serum growth hormone (GH) levels were determined in the offspring after four different experimental paradigms. In controls, administration of cyproheptadine (a serotonin-blocking agent), or insulin, or exposure to cold, caused decreases in the levels of serum GH, whereas dopamine-induced inhibition in GH release was observed only in 10-day-old rats. In contrast, among neonates exposed continuously to ethanol, only cyproheptadine produced decreases in serum GH levels similar to controls. In these ethanol-treated animals, insulin hypoglycemia, cold exposure, or dopamine-induced reductions in serum GH levels were not seen. Withdrawal from ethanol at birth produced similar GH responses to cyproheptadine, cold exposure, and dopamine as those observed in neonatal rats exposed continuously to ethanol. A delayed GH-lowering effect of insulin was observed in the withdrawal group indicating that these neurochemical changes may depend on the duration of exposure. The basal GH levels were altered also after ethanol exposure. These data would be consistent with the hypothesis that maternal ethanol ingestion causes an alteration in biogenic amines regulation of secretion of GH in the offspring.

show abstract

Section: Thadani Discussionsupporting

confidence: 90%

“…3, 8, 12-15, for reviews see ref. 9, 20], In particular, one of these studies has shown that in 10-day-old rats, 5-hydroxytryptophan-induced elevations in plasma GH levels were significantly reduced by pretreatment with selective inhibi tors of serotonin re-uptake [2]. In addition, Stuarts t at.…”

mentioning

confidence: 99%

Effect of Maternal Ethanol Ingestion on Control of Growth Hormone Secretion by Biogenic Amines in Rat Offspring

Thadani¹

1984

Neuroendocrinology

View full text Add to dashboard Cite

show abstract

“…Recent data seem to support this suggestion. However, the role of serotonin remains uncertain; some drugs characterized as serotonin antagonists, for example cypro heptadine, have failed to modify PRL secretion in man, but these compounds also exhibit anticholinergic, antihistaminic and antidopaminergic properties (13).…”

Section: Discussionmentioning

confidence: 99%

Effect of Two Serotonin Antagonists on Prolactin Release Induced by Breast Stimulation in Postpartum Women

Lancranjan¹,

Pozo²,

Picciolini³

et al. 1979

Horm Res

View full text Add to dashboard Cite

The possible role of serotonin on prolactin (PRL) secretion was investigated by measuring PRL plasma levels before and after mechanical breast stimulation in puerperal women. Two serotonin antagonists, methysergide, an ergot-derivative, and pizotifen, a non-ergot compound, were used in the trial. After a control stimulation test on postpartum day 1, each mother received on day 2 at 7 a.m. 2 mg of methysergide (n = 7), 1 mg pizotifen (n = 6), or placebo (n = 6). At 9 and 9.30 a.m. after 30-min breast stimulation, blood was drawn for plasma PRL measurements. The test was repeated on postpartum day 5 after a 72 hour treatment with methysergide (7 cases) 1 mg q.i.d., pizotifen (6 cases) 0.5 mg q.i.d. and placebo (6 cases). Basal PRL was not modified by pizotifen, but treatment with methysergide induced a significant reduction (p < 0.001) on the 5th postpartum day. Pizotifen administration failed to significantly modify the transient hyperprolactinemia induced by suckling, but an inhibition of this effect by methysergide was conspicuous after acute administration (p < 0.05) and after 3-days treatment (p < 0.001). Since PRL suppression is common following the administration of ergot derivatives characterized as dopamine agonists, the inhibitory effect of methysergide on PRL secretion may be ascribed to a dopaminergic effect inherent in its ergot structure; in contrast, pizotifen, a non-ergot serotonin antagonist, was ineffective. However, since it is known that presently available compounds are not solely serotonin antagonists, the role of serotonin in the modulation of PRL secretion in man cannot be clarified until a pure antagonist drug is available.

show abstract

“…This last action was prevented by pretreat ment with pimozide (20). Basal serum PRL concentration was unaffected by intraperitoneal metergoline in intact infant rats (19). The rat PRL responses to 5-hydroxytryptophan (19,20), to quipazine (20,84) and to fenfluramine (84) administration were markedly inhibited by metergoline pretreatment.…”

Section: Prolactinmentioning

confidence: 96%

Endocrine Profile and Therapeutic Employment of a New Prolactin-Lowering Drug, Metergoline

Ferrari

Reschini

Peracchi

et al. 1980

Gynecol Obstet Invest

View full text Add to dashboard Cite

Metergoline is an ergoline derivative with potent peripheral and central antiserotoninergic properties which has recently been shown to possess a marked prolactin (PRL)-lowering activity. This drug significantly decreases serum PRL levels after acute administration in normal subjects, in puerperal women, and in most hyperprolactinemic patients with or without pituitary tumor. Its PRL-lowering effect is unaffected by pimozide pretreatment in healthy subjects, and is frequently dissociated from that of bromocriptine in hyperprolactinemic patients. The drug does not affect the secretion of growth hormone (GH), thyrotropin and gonadotropins, while it blunts the corticotropin response to centrally but not peripherally-acting stimuli in normal subjects. In acromegalics, metergoline reduces serum PRL as well as GH levels, both actions being prevented by pimozide pretreatment. Improvement in oral glucose tolerance with unchanged insulin secretion is observed after a short course of metergoline treatment in patients with chemical diabetes. The PRL-lowering action of the drug is sustained during chronic treatment in hyperprolactinemic subjects. Inhibition of puerperal lactation may be obtained by a few days metergoline treatment in almost all treated women. Normalization of serum PRL levels and restoration of cyclic ovarian function are achieved within 1–4 months of treatment with the drug in most women with hyperprolactinemic amenorrhea. The possible role of metergoline in the treatment of other endocrine disorders such as normoprolactinemic amenorrhea, sexual impotence, Cushing’s disease, acromegaly and mild diabetes mellitus remains to be determined. Although the PRL-lowering effect and the therapeutic employment of metergoline

show abstract

Effect of 5-Hydroxytryptophan on Prolactin and Growth Hormone Release in the Infant Rat: Evidence for Different Neurotransmitter Mediation

Cited by 26 publications

References 28 publications

Effect of Maternal Ethanol Ingestion on Control of Growth Hormone Secretion by Biogenic Amines in Rat Offspring

Effect of Maternal Ethanol Ingestion on Control of Growth Hormone Secretion by Biogenic Amines in Rat Offspring

Effect of Two Serotonin Antagonists on Prolactin Release Induced by Breast Stimulation in Postpartum Women

Endocrine Profile and Therapeutic Employment of a New Prolactin-Lowering Drug, Metergoline

Contact Info

Product

Resources

About