Search results for "PROLACTIN"
showing 10 items of 71 documents
The L-glutamate transporters GLAST (EAAT1) and GLT-1 (EAAT2): expression and regulation in rat lactating mammary gland.
1999
The Na(+)-dependent L-glutamate transporters GLAST (EAAT1) and GLT-1 (EAAT2), were expressed in rat lactating mammary gland, but EAAC1 (EAAT3) was not. GLT-1 expression in rat lactating mammary gland was constant in all the physiological situations studied; however, the GLAST expression is under tight regulation. Fasting for 24 h decreased the GLAST expression which returned to control values after refeeding. Weaning for 24 h produced a decrease in GLAST expression through a mechanism independent of prolactin deficiency. Resuckling for 6 h returned the expression of this transporter to control values. There is a correlation between the levels of GLAST (mRNA and protein) and the in vivo upta…
Effects of L-tyrosine and L-tryptophan on the cardiovascular and endocrine system in humans
1990
Brain catecholamine and serotonin neurons are intimately involved in a number of relevant physiological functions such as cardiovascular regulation, neuroendocrine output from the anterior pituitary (e.g. ACTH, prolactin), regulation of behavior (e.g. aggression, sleep, locomotor and sexual behavior), mood or appetite control [1–5]. The modification of transmitter synthesis and release appears to be remarkably correlated with the subsequent physiological changes observed. While there are numerous pharmacological approaches that affect the respective neurotransmitter products (i.e. the catecholamines dopamine, noradrenaline and adrenaline and the indoleamine serotonin), one particular attrac…
Cardiovascular and Endocrine Properties of L-Tryptophan in Combination with Various Diets
1991
Brain serotonin neurons are intimately involved in a number of relevant physiological functions such as cardiovascular regulation, neuroendocrine output from the anterior pituitary (e.g. ACTH, prolactin), regulation of behavior (e.g. agression, sleep, locomotor and sexual behavior), mood or appetite control (Fernstrom, 1983; Lehnert et al., 1987; Spring et al., 1987; Wurtman, 1987). The synthesis of brain serotonin is dependent on the availability of the large neutral amino acid L-tryptophan that is hydroxylated to 5-L-hydroxytryptophan and subsequently decarboxylated to yield serotonin. The rate-limiting enzyme tryptophan hydroxylase has a Michaelis constant of approximately 2–3 x 10−5 M w…
Nitric oxide triggers mammary gland involution after weaning: remodelling is delayed but not impaired in mice lacking inducible nitric oxide synthase
2010
During mammary gland involution, different signals are required for apoptosis and tissue remodelling. To explore the role of NO in the involution of mammary tissue after lactation, NOS2 (inducible nitric oxide synthase)-KO (knockout) mice were used. No apparent differences were observed between NOS2-KO and WT (wild-type) animals during pregnancy and lactation. However, upon cessation of lactation, a notable delay in involution was observed, compared with WT mice. NOS2-KO mice showed increased phosphorylation of STAT (signal transducer and activator of transcription) 5 during weaning, concomitant with increased beta-casein mRNA levels when compared with weaned WT glands, both hallmarks of th…
Mechanism of New Antipsychotic Medications
2003
Antagonism of D 2 -like dopamine receptors is the putative mechanism underlying the antipsychotic efficacy of psychotropic drugs. Positron emission tomographic studies suggest that the antipsychotic effect of dopamine receptor antagonists occurs within a therapeutic window between 60% and 80%(striatal) D 2 receptor occupancy. The incidence of extrapyramidal side effects increases above the 80% threshold. However, the novel atypical antipsychotic drug, aripiprazole, occupies up to 95% of striatal D 2 -like dopamine receptors at clinical doses, and the incidence of extrapyramidal side effects with aripiprazole is no higher than with placebo. The most likely explanation for this finding is ari…
Regulation of PTHrP and PTH/PTHrP receptor by extracellular Ca2+ concentration and hormones in the breast cancer cell line 8701-BC.
2000
AbstractIt was previously reported that 8701-BC breast tumour cells express the gene for parathyroid hormonerelated peptide (PTHrP) and PTH/PTHrP receptor (PTHrPR) and release immunoreactive PTHrP (iPTHrP) into the extracellular medium. Since the regulation of PTHrP and PTHrPR by breast cancer cells has been poorly investigated so far, we have chosen the 8701- BC cell line as a model system to investigate whether alterations in the extracellular Ca[2+] concentration ([Ca[2+]]) and treatment with some wellknown differentiation agents for breast cells, such as dimethyl sulfoxide, hydrocortisone, progesterone, prolactin, alltrans retinoic acid and transforming growth factorβ1 might (i) modulat…
Hepatic amino acid uptake is decreased in lactating rats. In vivo and in vitro studies.
1994
To study the redistribution of amino acids to the mammary gland during lactation we used lactating and virgin rats fed liquid diets. Virgin rats were divided in two groups: one group was fed daily a diet containing the same amount of protein that was consumed the previous day by lactating rats (high protein diet-fed rats), and the other virgin group was fed the normal liquid diet (control). The hepatic availability of amino acids was significantly higher in the lactating rats than in the other two groups, but the uptake and fractional extraction of amino acids by the liver were lower in lactating rats than in the high protein-fed virgin controls. When primary hepatocyte cultures were used, …
Subclinical hypothyroidism and erectile dysfunction: The potential nexus
2020
Purpose: The aim of the study was to evaluate the link between subclinical hypothyroidism (SCH) and erectile dysfunction (ED). Materials and Methods: Seventy-two male patients aged 23–41 years with SCH compared with 25 healthy matched subjects were recruited, and they were divided into Group A: healthy controls (n = 25), Group B: patients with SCH with ED (n = 43), and Group C: patients with SCH without ED (n = 29). Thyroid function test and hormonal assay included total testosterone (TT), sex hormone-binding globulin, free androgen index, and prolactin (PRL) were measured; erectile function was assessed by the 5-item version of the International Index of Erectile Function (IIEF-5) question…
Mapping the actions of prolactin in the brain: sexual dimorphism, steroid regulation and the neuroendocrinology of maternal behaviour
2017
El comportamiento maternal cumple la función de proteger a la descendencia en su periodo de mayor vulnerabilidad y asegurar su supervivencia y bienestar. Esta colección de conductas sociales será expresada por la madre exclusivamente durante el periodo postparto, como resultado de la modulación del sustrato neural responsable de la expresión de la conducta social y reproductiva. Los agentes que llevan a cabo dicha modulación para inducir la expresión del comportamiento maternal incluyen, entre otros, señales endocrinas específicas de la gestación y lactancia. Entre éstas destaca la prolactina, hormona adenohipofisaria estrechamente vinculada con la adaptación del organismo a la maternidad. …
The medial amygdala as a key neural centre in maternal aggression: genetic, neural and behavioural analyses
2019
In rodents, as macrosmatic animals, chemosensory processing plays an instrumental role in guiding the expression of social, sexual and maternal behaviours. Social odours and pheromones are processed by the main and the accessory olfactory systems, which information converge mainly in the medial amygdala (Me). The Me, in turn, plays a central role in the vomeronasal–sensorimotor integration that leads to specific behavioural responses such as the above-mentioned social and maternal behaviours. Maternal behaviour comprises physiological and behavioural adaptations that help the dams to successfully raise their offspring. This behaviour is expressed in a wide range of vertebrate species and ca…