-
Annales D'endocrinologie Jun 2016
Topics: Animals; Female; Humans; Insulin-Secreting Cells; Mice; Mice, Knockout; Pancreas; Placenta; Pregnancy; Prolactin; Receptors, Prolactin
PubMed: 27155773
DOI: 10.1016/j.ando.2016.04.008 -
European Journal of Pharmacology Sep 2000The effects of prolactin on animal behavior include the stimulation of novelty-induced grooming in rats. This effect has been demonstrated in hyperprolactinaemic animals... (Review)
Review
The effects of prolactin on animal behavior include the stimulation of novelty-induced grooming in rats. This effect has been demonstrated in hyperprolactinaemic animals bearing pituitary homografts under the kidney capsule or after intracerebroventricular (i.c.v.) administration of prolactin. Since plasma prolactin levels in hyperprolactinaemic rats are similar to those of animals injected with low doses of rat prolactin, we studied the effects of this hormone injected subcutaneously (s.c.) in a dose range of 5-50 microg/kg. Novelty-induced grooming was enhanced only in rats injected with 5 or 10 microg/kg rat prolactin, whereas no effect was observed after the s.c. injection of the higher dose. The sexual behavior of male rats is also affected by prolactin. Male rats with normal mating activity showed enhanced sexual behavior when injected s.c. with rat prolactin (5, 10 or 50 microg/kg). In animals with poor sexual performance or in impotent rats, prolactin (5 or 10 microg/kg, but not 50 microg/kg) restored the full pattern of sexual behavior. An increased lordosis quotient was also observed in ovariectomized rats treated with prolactin 5 or 10 microg/kg. These results suggest that, besides the duration of hyperprolactinaemia, the effective level of plasma prolactin is important for the expression of the behavioral effects of this hormone.
Topics: Animals; Dose-Response Relationship, Drug; Female; Grooming; Male; Prolactin; Rats; Sex Characteristics; Sexual Behavior, Animal
PubMed: 11033320
DOI: 10.1016/s0014-2999(00)00678-6 -
Acta Endocrinologica. Supplementum 1978
Topics: Amino Acid Sequence; Animals; Female; Humans; Hypothalamus; Lactation; Menstruation; Pregnancy; Prolactin; Reproduction
PubMed: 274040
DOI: No ID Found -
Revue Du Rhumatisme (Ed. Francaise :... Apr 1994Increasing evidence suggest that prolactin (PRL) has important immunoregulatory properties and may play a role in the pathogenesis and disease expression of certain... (Review)
Review
Increasing evidence suggest that prolactin (PRL) has important immunoregulatory properties and may play a role in the pathogenesis and disease expression of certain autoimmune diseases. Prolactin is co-mitogenic on murine and human lymphocytes, induces the formation of IL-2 cell surface receptor and modulates the expression of various growth factor related genes. Prolactin also stimulates antibody production both in vivo and in vitro. Specific high affinity prolactin-receptors have been described on T and B lymphocytes as well as on monocytes. They are distributed on heterogeneous lymphocyte subsets and they showed imbalance in autoimmune situations. Lymphocytes may produce PRL-like proteins biologically active that function as autocrine growth factors for lymphoproliferation. Hyperprolactinemia has been found in male patients with systemic lupus erythematosus (SLE) and also during pregnancy in SLE patients. Hyperprolactinemia is correlated with clinical and serological activity in a subset of SLE patients. High levels of PRL aggravates disease activity and accelerates mortality in the B/W mouse model of SLE. In rheumatoid arthritis an excessive and upregulated secretion of PRL has been shown. Hyperprolactinemia has also been shown in a subset of patients with primary Sjögren's syndrome. High PRL levels have been found in Reiter's syndrome patients and bromocriptine treatment has been reported effective in these patients and psoriatic arthritis patients. These data support a potential role of this immunoregulatory hormone in the pathogenesis of some rheumatic diseases.
Topics: Endocrine Glands; Female; Humans; Immune System; Male; Nervous System Physiological Phenomena; Pregnancy; Prolactin; Rheumatic Diseases
PubMed: 7920527
DOI: No ID Found -
Acta Endocrinologica Jul 1993Prolactin modulates maternal functions and is involved in behaviour. Binding sites have been identified in the hypothalamus and substantia nigra. Hyperprolactinaemia... (Review)
Review
Prolactin modulates maternal functions and is involved in behaviour. Binding sites have been identified in the hypothalamus and substantia nigra. Hyperprolactinaemia stimulates dopamine turnover in several areas of the brain, including the nucleus accumbens, and reduces turnover in other regions, e.g. the substantia nigra. Hyperprolactinaemia stimulates the opioidergic system. The portal concentration of dopamine and oxytocin (a prolactin stimulatory substance) may be increased in hyperprolactinaemia. In mammals, prolactin is associated with learning, stimulation of the immune response, reduction of body temperature and increased corticosterone secretion. It is involved in the behavioural aspect of reproduction. Secretion is strongly stimulated in the female rat on exposure to pups. Hyperprolactinaemia in male rats reduces sexual behaviour. Hyperprolactinaemia reduces libido in both men and women but in men it is also associated with low testosterone levels. There is evidence that in families characterized by an absent or alcoholic father young girls may be predisposed to develop hyperprolactinaemia later in life as a reaction to losses. The underlying mechanism of such a psychosomatic reaction, a typical example of which is pseudopregnancy, may be an extemporaneous activation of a neuroendocrine "maternal subroutine" characteristic of pregnancy. Prolactinomas may result from somatic changes occurring in activated lactotrophs.
Topics: Animals; Behavior; Behavior, Animal; Female; Humans; Hyperprolactinemia; Libido; Male; Prolactin
PubMed: 8372607
DOI: No ID Found -
L'Encephale 1987Different neurotransmitters (Dopamine, serotonin, GABA...) and hormones (TRH, oestrogenes...) are involved in the central regulation of prolactin synthesis and release.... (Review)
Review
Different neurotransmitters (Dopamine, serotonin, GABA...) and hormones (TRH, oestrogenes...) are involved in the central regulation of prolactin synthesis and release. Under physiological conditions, prolactin levels are related to correlate with age, sex, sexual maturational changes (puberty, menopause...), menstrual cycling... In this review of literature there exists a great amount of data concerned with changes in prolactin in affective disorders illustrating the validity of the biochemical and neuroendocrinological approach specially in depression. Different research paradigms are presently reviewed: measurement of plasma levels of prolactin under basal conditions, in a circadian pattern or after pharmacological challenge with TRH and/or morphine (stimulation), L-dopa and/or dexamethasone (inhibition) and its response to antidepressant drugs. The authors emphasize the contradictory results reported in the literature and suggest the need for extreme caution before considering the validity of prolactin as a biochemical test in depression.
Topics: Animals; Antidepressive Agents; Depressive Disorder; Humans; Prolactin
PubMed: 3297633
DOI: No ID Found -
Lancet (London, England) Aug 1979
Topics: Adipose Tissue; Circadian Rhythm; Gonads; Growth Substances; Humans; Prolactin; Water-Electrolyte Balance
PubMed: 89338
DOI: No ID Found -
Pituitary Sep 2003Prolactin (PRL) promotes tumor growth, as recently highlighted by the spontaneous appearance of prostate hyperplasia and mammary neoplasia in PRL transgenic mice.... (Review)
Review
Prolactin (PRL) promotes tumor growth, as recently highlighted by the spontaneous appearance of prostate hyperplasia and mammary neoplasia in PRL transgenic mice. Increasing experimental evidence argues for the involvement of autocrine PRL in this process. Human (h)PRL receptor antagonists have been developed to counteract these undesired proliferative actions of PRL. However, all PRL receptor antagonists obtained to date exhibit partial agonism, limiting their therapeutic use as full antagonists. This is the case for the first generation antagonists (the prototype of which is G129R-hPRL) that we developed ten years ago, which display antagonistic activity in some, but not all in vitro bioassays, and fail to inhibit PRL activity in transgenic mice expressing this analog. We recently developed new human PRL antagonists devoid of agonistic properties, and therefore able to act as pure antagonists. This was demonstrated using several in vitro bioassays, including assays able to detect extremely low levels of receptor activation. These new compounds also act as pure antagonists in vivo, as demonstrated by their ability to competitively inhibit PRL-triggered signaling cascades in various target tissues (liver, mammary gland and prostate). Finally, using transgenic mice specifically expressing PRL in the prostate, which have constitutively activated signaling cascades and prostate hyperplasia, these new PRL analogs are able to completely revert PRL-activated events to basal levels. These second generation antagonists are good candidates to be used as inhibitors of the growth-promoting actions of hPRL.
Topics: Antineoplastic Agents; Humans; Neoplasms; Prolactin; Receptors, Prolactin
PubMed: 14703018
DOI: 10.1023/b:pitu.0000004799.41035.9f -
Pituitary 2008In several respects prolactin is unique among anterior pituitary hormones. The primary regulation of prolactin secretion is mediated through hypothalamic inhibition, and... (Review)
Review
In several respects prolactin is unique among anterior pituitary hormones. The primary regulation of prolactin secretion is mediated through hypothalamic inhibition, and the diagnosis of hyperprolactinemia can be established without the use of stimulation or suppression tests. Documenting the presence of hyperprolactinemia is not difficult-the challenge is in identifying the cause of the hormone hypersecretion. With immunoradiometric assays falsely low levels of prolactin are occasionally seen in patients with macroadenomas and very high serum prolactin (the hook effect). Macroprolactin should be suspected when a patient with hyperprolactinemia does not present with typical clinical symptoms, and all hyperprolactinemic sera should be screened for macroprolactin. With prolactinomas, prolactin levels generally parallel tumor size. Prolactin secreting macroadenomas are typically associated with levels that exceed 250 microg/l and may exceed 1,000 microg/l. Large non-functioning adenomas also lead to hyperprolactinemia but levels virtually never exceed 94 microg/l. Acquired and isolated prolactin deficiency is rare.
Topics: Diagnosis, Differential; Humans; Hyperprolactinemia; Pituitary Function Tests; Pituitary Neoplasms; Prolactin
PubMed: 18404389
DOI: 10.1007/s11102-008-0107-5 -
Journal of Mammary Gland Biology and... Jan 1997The availability of recombinant growth hormones, prolactins, placental lactogens and a few soluble extracellular domains of their receptors have extended our ability to... (Review)
Review
The availability of recombinant growth hormones, prolactins, placental lactogens and a few soluble extracellular domains of their receptors have extended our ability to study the interaction of somatogenic and lactogenic hormones with their receptors. Modifications of their respective cDNAs have enabled the preparation of sufficient amounts of the corresponding proteins. The present review summarizes two aspects of these interactions: (a) the relationship between binding, the apparent ability to dimerize the receptors and biological activities in vitro and in vivo; and (b) the effect of mutations on selective changes in the ability of human growth hormone and bovine placental lactogen to interact with somatogenic and lactogenic receptors. In view of this summary, strategies for preparing a second generation of biologically relevant recombinant hormones are discussed.
Topics: Amino Acid Sequence; Animals; Dimerization; Growth Hormone; Humans; Molecular Sequence Data; Mutagenesis, Site-Directed; Placental Lactogen; Prolactin; Recombinant Proteins; Structure-Activity Relationship
PubMed: 10887521
DOI: 10.1023/a:1026377614430