Prolactin

About: Prolactin is a research topic. Over the lifetime, 22356 publications have been published within this topic receiving 609537 citations. The topic is also known as: lactotropin, & PRL,.

Participation of Serotonin-Containing Neurons in the Suckling-Induced Rise in Plasma Prolactin Levels in Lactating Rats

Abstract: Plasma prolactin levels were measured by radioimmuno-assay in free-moving lactating rats bearing heart cannulas. Litters adjusted to 6 pups were returned to the mothers after a separation of 8–12 h fr

Catecholamine inhibition of prolactin secretion by isolated rat adenohypophyses.

Abstract: Rat adenohypophyses were incubated in medium 199 containing l-14C-glycine or a Krebs-Ringer-bicarbonate solution with glucose and a mixture of essential and non-essential amino acids. Dialyzed medium and anterior pituitary homogenates were elect rophoresed on polyacrylamide gel. After staining with Amido Black, the growth hormone and prolactin bands were quantified by microdensitometry and cut from the gel column for measurement of radioactivity. Growth hormone and prolactin contained in the medium were also measured by radioimmunoassay techniques. Epinephrine and norepinephrine inhibited prolactin release into the medium and this was associated with a proportionate rise in anterior pituitary prolactin. The catecholamines decreased total radioactive glycine incorporated into medium and pituitary prolactin but after 4 hr of incubation this decrease was not statistically significant. Inhibition of prolactin release occurred with concentrations of .5 μg/ml or greater of norepinephrine, and 1 μg/ml or greater...

Acute and chronic estrogen effects upon serum somatomedin activity, growth hormone, and prolactin in man.

Abstract: Estrogen (E) reduces bioassayable GH-dependent serum somatomedin (SM) activity in acromegalics without affecting plasma growth hormone (GH) levels and inhibits the rise of SM activity normally produced by GH administration in GH-deficient subjects. We have now investigated the effect of E administration on serum SM activity and on plasma GH and prolactin (PRL) in 6 adult male subjects without pituitary pathology. Chronic E administration (ethinyl estradiol 0.5 mg/day for 7 to 70 days) reduced serum SM activity by 40 to 62% in each of 4 subjects (P < 0.02 to <0.001). In 3 of the subjects, basal GH levels increased by 75 to 300% (P < 0.05 to <0.001) and basal PRL levels increased by 90 to 200% (P < 0.01 to <0.001). While iv administration of normal saline did not significantly affect either SM or GH, iv administration of E (bolus injection of 25 mg conjugated estrogens, USP) to 5 subjects resulted in: a) a 46 to 80% decrease in serum SM activity in all subjects, proceeding with an apparent half-lif...

Effect of RF-Amide-Related Peptide-3 on Luteinizing Hormone and Follicle-Stimulating Hormone Synthesis and Secretion in Ovine Pituitary Gonadotropes

Abstract: GnRH provides the primary stimulus for the reproductive axis, but original work also revealed the existence of a gonadotropin-inhibitory hormone (GnIH) in birds. In mammals, GnIH properties are displayed by a hypothalamic dodecapeptide, which is a member of the RF-amide family, namely RF-amide-related peptide (RFRP)-3. This peptide inhibits GnRH-stimulated gonadotropin secretion from ovine pituitary cells in culture, but it is not known whether there are effects on gonadotropin synthesis. The aim of the present study was to determine the effects of RFRP-3 on the expression of genes for β-subunits of the gonadotropins in ovine pituitary cells from gonadectomized ewes and rams. Cells in primary culture were given GnRH or vehicle pulses every 8 h for 24 h with and without RFRP-3 treatment. GnRH stimulated LH and FSH secretion, which was reduced by RFRP-3. Quantitative real-time PCR revealed increased expression of LHβ and FSHβ subunit genes after GnRH treatment and a specific reduction in expression after RF...