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Endocrine Reviews Dec 1996
Review
Topics: Animals; Brain; Gene Expression Regulation; Humans; Immune System; Prolactin; Reproduction
PubMed: 8969972
DOI: 10.1210/edrv-17-6-639 -
Progress in Food & Nutrition Science 1990The principal lactogenic hormone, prolactin, secreted by the anterior pituitary is critical to the establishment of lactation, milk macronutrient content and milk... (Review)
Review
The principal lactogenic hormone, prolactin, secreted by the anterior pituitary is critical to the establishment of lactation, milk macronutrient content and milk production. The concentration of circulating prolactin increases during pregnancy so that by the end of gestation, levels are 10 to 20 times over normal amounts. However, prolactin is prevented from exerting its effect on milk secretion by elevated levels of progesterone. Following clearance of progesterone and estrogen at parturition, copious milk secretion begins. The minimal hormonal requirements for normal lactation to occur are prolactin, insulin and hydrocortisone. Prolactin stabilizes and promotes transcription of casein mRNA; may stimulate synthesis of alpha-lactalbumin, the regulatory protein of the lactose synthetase enzyme system; and increases lipoprotein lipase activity in the mammary gland. Prolactin levels decrease as lactation is established but nursing stimulates prolactin release from the pituitary which promotes continued milk production. Prolactin is secreted into milk at levels representative of the average circulating concentration. The physiological significance of milk prolactin to the infant is uncertain. Prolactin exists in three heterogenic forms which possess varying biological activity. The monomer with a molecular weight of 23 kDa is found in greatest quantity and is the principal biologically active form. The pattern of heterogeneity changes during pregnancy to favor even more monomer in proportion to the dimer. However, during lactation, the proportion of the monomer in circulation decreases in response to selective uptake of the monomer by the mammary gland. Over 90 percent of the prolactin in milk is present as the monomer. Prolactin may exert some of its biological effect by a shift in the ratio of active to less active forms of the molecule.
Topics: Animals; Calcium; Diet; Female; Humans; Lactation; Milk; Milk, Human; Nutritional Physiological Phenomena; Pregnancy; Prolactin
PubMed: 2092340
DOI: No ID Found -
Asian Journal of Andrology 2019Although elevated prolactin levels have been shown to inhibit penile erection, the relationship between prolactin and erection of the penile tip or base has not been...
Although elevated prolactin levels have been shown to inhibit penile erection, the relationship between prolactin and erection of the penile tip or base has not been extensively researched. We therefore investigated the prolactin's effects on erection of the penile tip and base, with a cross-sectional study of 135 patients with erectile dysfunction, based on scores of ≤21 on the International Index of Erectile Function-5. All patients were tested for nocturnal penile tumescence, blood pressure, serum glucose, total cholesterol, triglyceride, high-density lipoprotein, low-density lipoprotein, luteinizing hormone, follicle-stimulating hormone, prolactin, estradiol, testosterone, and progesterone. Univariate and multivariate analyses were used to assess the associations between prolactin levels and erection at the penile tip and base. We found no obvious relationship between erection time at penile tip and prolactin levels, but observed a negative correlation between base erection time and prolactin level (hazard ratio: -2.68; 95% confidence interval [CI]: -5.13--0.22). With increasing prolactin concentration, multivariate analysis showed obvious reduction in base erection time among patients with normal Rigiscan results (hazard ratio: -3.10; 95% CI: -7.96-1.77; P < 0.05). Our data indicate that prolactin inhibits penile erection, particularly at the penile base. In addition, when the effective erection time of the penile base lasts longer than 10 min, prolactin has a more obvious inhibitory effect on penile base erection.
Topics: Adult; Cross-Sectional Studies; Erectile Dysfunction; Humans; Male; Penile Erection; Prolactin; Time Factors
PubMed: 31044754
DOI: 10.4103/aja.aja_22_19 -
Communications Biology Jan 2021In many species, ejaculation is followed by a state of decreased sexual activity, the post-ejaculatory refractory period. Several lines of evidence have suggested...
In many species, ejaculation is followed by a state of decreased sexual activity, the post-ejaculatory refractory period. Several lines of evidence have suggested prolactin, a pituitary hormone released around the time of ejaculation in humans and other animals, to be a decisive player in the establishment of the refractory period. However, data supporting this hypothesis is controversial. We took advantage of two different strains of house mouse, a wild derived and a classical laboratory strain that differ substantially in their sexual performance, to investigate prolactin's involvement in sexual activity and the refractory period. First, we show that there is prolactin release during sexual behavior in male mice. Second, using a pharmacological approach, we show that acute manipulations of prolactin levels, either mimicking the natural release during sexual behavior or inhibiting its occurrence, do not affect sexual activity or shorten the refractory period, respectively. Therefore, we show compelling evidence refuting the idea that prolactin released during copulation is involved in the establishment of the refractory period, a long-standing hypothesis in the field of behavioral endocrinology.
Topics: Animals; Female; Male; Mice, Inbred C57BL; Prolactin; Sexual Behavior, Animal; Mice
PubMed: 33398068
DOI: 10.1038/s42003-020-01570-4 -
The Journal of Biological Chemistry Feb 1986Rat prolactin exhibits microheterogeneity when examined in electrophoretic systems, running as three isoforms having the same molecular weight but different net charges... (Comparative Study)
Comparative Study
Rat prolactin exhibits microheterogeneity when examined in electrophoretic systems, running as three isoforms having the same molecular weight but different net charges (prolactins 1, 2, and 3 with isoform 3 being the most acidic). As there is precedent for the phosphorylation of a pituitary hormone and phosphorylation is a common cause of microheterogeneity, we examined the possibility that rat prolactin existed in differentially phosphorylated forms. The investigation included examinations of rat prolactin phosphorylation both in vitro and in vivo. For the in vitro studies, purified rat prolactin was incubated with [gamma-32P]ATP and low levels of each of five purified protein kinases. Phosphorylated rat prolactin was identified by autoradiography of silver-stained one- and two-dimensional gels. For the in vivo studies, rat anterior pituitary cells in primary culture were incubated in the presence of H3 32PO4 for 2 or 12 h, after which time the proteins were extracted from the cells, cold acetone-precipitated, or immunoprecipitated and run on two-dimensional gels. We report the in vitro phosphorylation of rat prolactin by cAMP-dependent protein kinase, casein kinase I, protease-activated kinase I, and the calcium/phospholipid-dependent kinase, that phosphorylation with these kinases results in phosphate incorporation only into isoforms 2 and 3, and the phosphorylation of prolactin in rat pituitary cells in primary culture.
Topics: Animals; Casein Kinases; Cells, Cultured; Electrophoresis, Polyacrylamide Gel; Peptide Hydrolases; Peptidyl-Dipeptidase A; Phosphorylation; Pituitary Gland, Anterior; Prolactin; Protein Kinase C; Protein Kinases; Rats
PubMed: 3003080
DOI: No ID Found -
European Eating Disorders Review : the... Jan 2012In completing this review, we aim to educate readers about the physiological importance of the hormone prolactin (PRL) in the treatment of patients with anorexia nervosa... (Review)
Review
OBJECTIVE
In completing this review, we aim to educate readers about the physiological importance of the hormone prolactin (PRL) in the treatment of patients with anorexia nervosa (AN).
METHOD
A comprehensive review of PRL was undertaken using existing published literature with specific focus on domains pertinent to the treatment of AN.
RESULTS
Prolactin influences multiple biological processes throughout the body. Disruption in its regulation can impact women's health issues such as menstruation and bone health, which are pertinent to AN treatment. The use of antipsychotics with high D2 receptor affinity for the augmented treatment of AN increases the potential risk of PRL-mediated adverse effects.
DISCUSSION
Although not intrinsic to underlying disease underpinnings, PRL has the capacity to affect and influence multiple outcome variables in treatment of patients with AN. Improved understanding, better screening and the completion of further prospective research are necessary to help facilitate and incorporate ongoing knowledge translation.
Topics: Anorexia Nervosa; Female; Humans; Prolactin; Prospective Studies; Treatment Outcome
PubMed: 21774041
DOI: 10.1002/erv.1119 -
Klinische Wochenschrift Jan 1979Human prolactin (hPRL) is the most recent anterior pituitary hormone in human endocrinology, whose structure has been elucidated in 1977. The possibility to measure hPRL... (Review)
Review
Human prolactin (hPRL) is the most recent anterior pituitary hormone in human endocrinology, whose structure has been elucidated in 1977. The possibility to measure hPRL in serum has led to a rapid increase of our knowledge of prolactin-physiology and -pathophysiology in men. hPRL is the only anterior pituitary hormone which is under predominantly inhibitory hypothalamic control. The effects of prolactin in the various species differ considerably, whereas in men it acts mainly upon the mammary gland and the gonadal system. Hyperprolactinemia leads typically to hypogonadism, amenorrhea and frequently galactorrhea. The hyperprolactinemia-hypogonadism-syndrome has been identified as a separate entity in recent years. Because of the relative frequency of this disease prolactin measurements have become of great importance in the diagnosis of sterility. Depending on the cause of hyperprolactinemia a neurosurgical, radiotherapeutical or medical treatment is indicated.
Topics: Amenorrhea; Biological Assay; Endocrine System Diseases; Female; Galactorrhea; Humans; Hypogonadism; Pregnancy; Prolactin
PubMed: 366279
DOI: 10.1007/BF01476976 -
Annals of the New York Academy of... 1988
Review
Topics: Animals; Brain; Drug Interactions; Grooming; Peptides; Prolactin; Rats; Synaptic Transmission
PubMed: 2839067
DOI: 10.1111/j.1749-6632.1988.tb38609.x -
Endocrine Reviews Jun 1995
Review
Topics: Amino Acid Sequence; Animals; Genetic Variation; Humans; Molecular Sequence Data; Polymorphism, Genetic; Prolactin; Sequence Homology, Amino Acid; Structure-Activity Relationship
PubMed: 7671851
DOI: 10.1210/edrv-16-3-354 -
La Revue Du Praticien Jun 1996Prolactinoma, a benign tumor originating from the lactotroph cells of the anterior pituitary, is responsible for signs and symptoms related to both hypersecretion of...
Prolactinoma, a benign tumor originating from the lactotroph cells of the anterior pituitary, is responsible for signs and symptoms related to both hypersecretion of prolactin and tumor mass. Hyperprolactinemia frequently causes menstrual cycle disturbances, galactorrhea and infertility in women, sexual disorders in men. Microadenomas, characterized by a largest diameter less than 10 mm, may induce frontal headaches, and macroadenomas (more than 10 mm in diameter) may also impair visual function through chiasma compression. Treatment modalities include dopamine agonist therapy such as bromocriptine which allows normalization of prolactin levels, restoration of gonadal functions and tumor shrinkage in most cases. In microadenomas a definitive cure may be achieved by transsphenoidal total selective adenomectomy.
Topics: Bromocriptine; Diagnosis, Differential; Dopamine Agents; Female; Humans; Magnetic Resonance Imaging; Male; Pituitary Neoplasms; Pregnancy; Prolactin; Prolactinoma
PubMed: 8881162
DOI: No ID Found