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Revue Medicale de Liege Feb 1980
Review
Topics: Adolescent; Amenorrhea; Bromocriptine; Circadian Rhythm; Cushing Syndrome; Empty Sella Syndrome; Estrogens; Female; Galactorrhea; Genitalia; Gonadotropins, Pituitary; Homeostasis; Humans; Hyperthyroidism; Hypothyroidism; Lactation Disorders; Male; Middle Aged; Neurosecretory Systems; Neurotransmitter Agents; Pituitary Neoplasms; Pregnancy; Prolactin; Receptors, Cell Surface
PubMed: 6102408
DOI: No ID Found -
American Journal of Obstetrics and... Jun 1990Elevated levels of serum and follicular fluid prolactin occur in women undergoing ovulation induction with both clomiphene citrate and gonadotropin therapy. Prolactin's...
Elevated levels of serum and follicular fluid prolactin occur in women undergoing ovulation induction with both clomiphene citrate and gonadotropin therapy. Prolactin's effect on oocyte fertilization and embryo cleavage has not been fully characterized. Using a murine model, we investigated the effect of prolactin on in vitro fertilization and subsequent embryo cleavage in media containing 150, 400, and 600 ng/ml purified mouse prolactin. No difference was found in fertilization rates when compared with control rates. Culture of both in vivo and in vitro fertilized two-cell embryos in murine prolactin at 150, 400, and 600 ng/ml showed no significant difference in blastocyst, morula, or embryo degeneration rates when compared with control rates. An assay for binding of murine prolactin to spermatozoa, oocytes, and the embryo at various cleavage stages revealed no specific murine prolactin binding. These in vitro experimental results fail to show a role for murine prolactin in effecting mature oocyte fertilization or subsequent embryo cleavage. The lack of binding of murine prolactin to the gametes and early developing embryo supports the in vitro findings.
Topics: Animals; Embryo, Mammalian; Embryonic and Fetal Development; Female; Fertilization; Fertilization in Vitro; Male; Mice; Mice, Inbred Strains; Models, Biological; Oocytes; Prolactin; Spermatozoa
PubMed: 2360588
DOI: 10.1016/0002-9378(90)90920-3 -
Pathologie-biologie Dec 1978Prolactin has been lately singled-out among the pituitary hormones, and as such the object of considerable research in the past 15 years. The frequency of prolactin... (Review)
Review
Prolactin has been lately singled-out among the pituitary hormones, and as such the object of considerable research in the past 15 years. The frequency of prolactin secreting adenomes is established now. The responsibility of iatrogenic factors (neuroleptics, oral contraceptives) in some hyperprolactinaemias is a known fact. The study of the inhibiting dopaminergic system was a landmark in the treatment of hyperprolactinaemia. During the recent Nice Congress, some issues remained unsettled on the physiological activities of prolactin. The matter is clearer when it comes to prolactin secretion. In equilibrium between inhibiting and stimulant factors, the secretion is controlled by the CNS, influenced by the hormonal environment, and its timing is the object of a retrocontrol. This is a very instructive pattern in endocrinology.
Topics: Animals; Breast; Breast Neoplasms; Central Nervous System; Female; Hormones; Humans; Hypothalamus; Male; Ovulation; Prolactin
PubMed: 370749
DOI: No ID Found -
International Journal of Peptide and... Apr 1987Prolactin was isolated from anterior lobes of elephant pituitary glands. It consisted of 199 amino acids with three disulfide bridges and two tryptophan residues as...
Prolactin was isolated from anterior lobes of elephant pituitary glands. It consisted of 199 amino acids with three disulfide bridges and two tryptophan residues as found in prolactin from other species. The sequence of the NH2-terminal 28 amino acids was determined and shown homologous with the ovine hormone. In comparison with ovine prolactin, a marked difference was seen in the methionine content; the elephant hormone possessed only 18-34% lactogenic potency. The conformation of elephant prolactin was examined by zero order, second order and circular dichroism spectroscopy. The alpha helical content was estimated to be about 60%. In comparison with prolactins from other species, the second order spectra of elephant prolactin suggest that the local microenvironment for one or both tryptophan residues is somewhat different.
Topics: Amino Acids; Animals; Chromatography, Gel; Chromatography, High Pressure Liquid; Elephants; Female; Pituitary Gland; Pregnancy; Prolactin; Rabbits; Receptors, Prolactin; Sheep
PubMed: 3596899
DOI: 10.1111/j.1399-3011.1987.tb02273.x -
La Clinica Terapeutica Dec 1980
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The Journal of Urology Jun 1980Elevated levels of serum prolactin in patients with pituitary tumors have been associated with hypogonadism, frequently manifested in men as impotence and/or loss of...
Elevated levels of serum prolactin in patients with pituitary tumors have been associated with hypogonadism, frequently manifested in men as impotence and/or loss of libido. The purpose of our study was to test the hypothesis that psychogenic and/or organic impotence may be a manifestation of a relative hyperprolactinemic state. We studied 30 men with the known diagnosis of impotence: 17 organic and 13 psychogenic. There were 11 normal, sexually active men used as controls. Serum prolactins were determined with the radioimmunoassay technique. There was no significant differences in serum prolactin levels among control, organic impotent and psychogenic impotent groups. Impotence does not seem to be related to hyperprolactinemia in men in the absence of pituitary disease.
Topics: Adult; Aged; Erectile Dysfunction; Humans; Male; Middle Aged; Pituitary Neoplasms; Prolactin; Psychophysiologic Disorders
PubMed: 7382002
DOI: 10.1016/s0022-5347(17)56166-2 -
The Biochemical Journal Oct 19681. A radioimmunoassay for ovine prolactin is described based on the inhibition of the reaction between (131)I-labelled ovine prolactin and guinea-pig or rabbit antiserum...
1. A radioimmunoassay for ovine prolactin is described based on the inhibition of the reaction between (131)I-labelled ovine prolactin and guinea-pig or rabbit antiserum to ovine prolactin. The extent of the reaction after a 4-day incubation period is determined by chromatoelectrophoresis or by adsorption of unchanged (131)I-labelled ovine prolactin on charcoal. The sensitivity is equal to 5.9ng. of prolactin/ml. of plasma with chromatoelectrophoresis, or 0.2ng. of prolactin/ml. of tissue extracts with the charcoal separation. 2. A complete cross-reaction demonstrated between ovine prolactin and caprine pituitary extracts allows the assay to be used to measure caprine prolactin. The partial cross-reactions between ovine prolactin and bovine prolactin and between ovine prolactin and bovine pituitary extract differ, and an alteration in the immunological activity of bovine prolactin during its isolation is suggested. Bovine prolactin in plasma may be measured against a bovine pituitary extract as standard. No cross-reactions were demonstrated with pituitary extracts from a number of other species. The extent of the contamination of ovine and bovine growth hormone preparations by their respective prolactins is shown. 3. Dilutions of ovine and caprine plasma inhibit the reaction between (131)I-labelled ovine prolactin and antiserum with the same characteristics as ovine prolactin. 4. The immunoreactive material in plasma fractionates on Sephadex G-200 and in sucrose density gradients as a single peak similar to that shown by freshly dissolved ovine prolactin. There is no evidence that ovine prolactin is bound to a plasma protein. 5. By suppressing prolactin secretion and assaying serial samples of plasma thereafter it is shown that the immunological activity of the surviving hormone becomes progressively altered with time. It is suggested that this alteration is usually not detected but introduces an element of uncertainty into the quantitative but not the qualitative value of the measurements obtained by reference to standard ovine prolactin.
Topics: Adsorption; Animals; Cattle; Charcoal; Chromatography; Dextrans; Electrophoresis; Goats; Growth Hormone; Guinea Pigs; Immune Sera; Iodine Isotopes; Methods; Pituitary Gland; Prolactin; Protein Binding; Rabbits; Radioimmunoassay; Sheep
PubMed: 5696866
DOI: 10.1042/bj1090831 -
The Pan African Medical Journal 2015
Topics: Adenoma; Antipsychotic Agents; Female; Humans; Hyperprolactinemia; Prolactin
PubMed: 26977248
DOI: 10.11604/pamj.2015.22.341.8235 -
Clinical and Investigative Medicine.... Feb 1995Although prolactin was discovered in the early 1930's in sheep, cows, birds etc., no human form had been because it was thought to be identical to human growth hormone...
Although prolactin was discovered in the early 1930's in sheep, cows, birds etc., no human form had been because it was thought to be identical to human growth hormone (HGH). In fact, prior to 1970, most endocrinologists doubted human prolactin even existed. Prolactin-like effects could be demonstrated from a homogenate of human pituitary but attempting to purify it identified only growth hormone. Independent histological studies had identified prolactin-secreting "pregnancy cells" fuelling the conviction that prolactin was a distinct and separate pituitary hormone. A search was begun for prolactin through protein synthesis studies using pituitaries from pregnant and postpartum monkeys. Proteins obtained in a radioactive peak were similar to, but not identical with, growth hormone by molecular weight and electrophoretic mobility. The hypothesis that the unknown protein peak represented synthesis of prolactin rather than growth hormone proved correct. Evidence was then obtained confirming that in the human pituitary prolactin and growth hormone synthesis could be distinguished using antibodies to human growth hormone or to sheep prolactin. Human prolactin purified from pituitary glands using immunological tools capable of distinguishing between the two hormones provided ultimate proof of a separate and distinct human prolactin, a hormone which has its major impact today in endocrinology and reproductive medicine. This discovery represented an exciting and truly international collaborative effort.
Topics: Animals; Canada; Female; Growth Hormone; Haplorhini; History, 20th Century; Humans; Pituitary Gland; Pregnancy; Prolactin; Radioimmunoassay
PubMed: 7768067
DOI: No ID Found -
Journal de Gynecologie, Obstetrique Et... 1989Prolactin plays a peripheral role in male reproductive function just as it does in female function. Prolactin, through the medium of immunocytochemistry acts on... (Review)
Review
Prolactin plays a peripheral role in male reproductive function just as it does in female function. Prolactin, through the medium of immunocytochemistry acts on testicular steroidogenesis through prolactin receptors which are sited on the Leydig cells. It alters the number of LH receptors and therefore the sensitivity of the testis to central stimulation and equally interferes with androgen synthesis. In the areas of physiological concentration the principal effect seems to be to stimulate secretion of testosterone by keeping up the number of LH receptors; but when there is acute hyperprolactinaemia, testosterone secretion is lowered or perhaps not changed at all because of a "post-receptor effect", in spite of there being larger numbers of LH receptors. The direct effect of prolactin on spermatogenesis has not yet been worked out and the results that have been obtained are controversial. Prolactin exerts a direct stimulating effect on the growth of prostatic cells working synergistically with testosterone through specific prolactin receptors. It could play a role in certain cancers of the prostate.
Topics: Humans; Male; Prolactin; Prostate; Testis
PubMed: 2654270
DOI: No ID Found