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,.

Sex hormone status of male patients with rheumatoid arthritis: evidence of low serum concentrations of testosterone at baseline and after human chorionic gonadotropin stimulation.

Abstract: Serum concentrations of luteinizing hormone, follicle-stimulating hormone, prolactin, 17 beta-estradiol, testosterone, androstenedione, dehydrotestosterone, dehydroepiandrosterone sulfate, and cortisol were examined in 14 men with rheumatoid arthritis (RA) and in age-matched osteoarthritis controls. Hypophyseal, adrenal, and testicular responses to stimulation with luteinizing hormone-releasing hormone, adrenocorticotropin, and human chorionic gonadotropin, respectively, were evaluated in 8 RA patients and in 8 age-matched healthy volunteers. Basal serum testosterone concentrations were significantly lower in male RA patients than in the osteoarthritis control subjects (P less than 0.01). After human chorionic gonadotropin stimulation, serum concentrations of testosterone were also lower in the RA patients than in normal healthy controls (P less than 0.05). These findings suggest that diminished testicular steroid biosynthesis might contribute to the serum testosterone deficiency observed in male RA patients.

Mammary gland development in prolactin receptor knockout mice.

Abstract: A germ line null mutation of the prolactin receptor gene has been produced by replacing exon 5 with the Tk-NEO cassette. Heterozygous females showed almost complete failure of lactation following their first pregnancy when mated at 6-8 weeks of age. The severity of this phenotype was reduced when heterozygotes were mated at 20 weeks and was absent following a second pregnancy when assessed by pup survival, although a longer lag time prior to weight increase at normal rates was seen in these litters. Histological and whole mount analysis of virgin mammary glands showed that heterozygous glands were smaller in size due to a less developed ductal structure with fewer branch points. Virgin knockout glands were small, composed of sparse, large, poorly branched ducts. This work provides an ideal model to further study the role of the prolactin receptor and its ligands in mammary development and physiology.

Prolactin and Growth Hormone Production as Influenced by Catecholamines and Agents that Affect Brain Catecholamines

Abstract: The in vitro influence of dopamine on the in vitro incorporation of leucine-4,5-3H into rat pituitary gland prolactin and growth hormone was studied. This catecholamine primarily inhibited

Effects of Sex Steroids on Prolactin Secreting Rat Pituitary Cells in Culture

Abstract: A clonal strain of rat pituitary tumor cells (GH3) was used to study the effects of different sex steroids on the production of prolactin (PRL). Hormone production was measured by radioimmunoassay and expressed as the amount of hormone which accumulated in the medium of monolayer cultures during 24 h. The stimulatory effect of 17β-estradiol (10−11M-10−6M) on PRL production was significant after 4 days and the maximum effect (300% of control cultures) was observed at 10−8M after 10 days of treatment. After removal of added 17β-estradiol, the production of PRL returned to control levels in 5 days. Progesterone (10−11M-10−6HM) caused a doserelated decrease in PRL production reaching 60% of control values at 10−6M. Testosterone (10−6M) stimulated the production of PRL (130% of controls), whereas 5α-dihydrotestosterone (10−6M) had a small effect (107% of controls) which was not always reproducible. None of the sex steroids affected cell growth. Progesterone (10−6M) inhibited the stimulatory effect of 17β-estra...

A Review of Endocrine Regulation of Metabolism during Lactation

Abstract: Lactogenesis signals the shift from uterine nutrient transfer to the fetus to neonatal nourishment at the mammary gland. Metabolic adaptations involved in this process are under endocrine regulation. Key events include an increase in blood flow to mammary tissue, a decrease in nutrient utilization by peripheral tissues and an increase in nutrient utilization by mammary tissue for milk synthesis. Deficits of certain substrates during early lactation require mobilization of those substrates from depot stores. Changes in metabolism of various tissues are related to changes in hormone receptor populations of those tissues and hormone concentrations in blood. Hormone receptors are therefore the primary mechanism by which information from the endocrine systems is linked to cellular metabolism. Endocrine changes at parturition result in dramatic changes in receptor populations of key tissues such as adipose and mammary tissues. Knowledge in this area, however, is incomplete. Relationship between hormone receptors and specific cellular metabolic pathways remains unresolved.