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,.

The role of catecholamines in the release of anterior pituitary prolactin in vitro.

Abstract: Rat hypothalamic extracts, dopamine (DA), norepinephrine (NE), and epinephrine (EP), were incubated with rat pituitary tissue in medium 199. In all cases rat hypothalamic extracts significantly inhibited pituitary prolactin (PRL) release in vitro. When the hypothalamic extracts were subjected to preincubation with a rat brain monoamine oxidase enzyme preparation (MAO) or ot aluminum oxide (alumina) catecholamine adsorption, the hypothalamic extracts lost their ability to inhibit PRL release in vitro Pepsin pretreatment did not impair the inhibition of PRL release by hypothalamic extracts and iproniazid 10 μg/ml of medium blocked the effect of MAO on the hypothalamic extracts. The DA and NE content of MAO treated and untreated hypothalamic extracts was measured by a fluorometric technique. The catecholamine containing acid eluate from the alumina adsorption procedure was able to inhibit PRL release to the same degree as untreated hypothalamic extracts. Dopamine (5.26 × 10−9 to 5.26 × 10−7M) and NE (2.42 × ...

Changes in the concentration of pituitary and steroid hormones in the follicular fluid of human graafian follicles throughout the menstrual cycle.

Abstract: The concentrations of FSH, LH, prolactin, oestradiol and progesterone were measured in peripheral plasma and follicular fluid of women throughout the menstrual cycle. With the exception of prolactin, concentrations of pituitary and steroid hormones in follicular fluid correlated with those in peripheral plasma. Follicle-stimulating hormone was present in a greater number of small follicles (smaller than 8mm) during or just after the peaks of FSH in peripheral plasma. During the mid-follicular phase the concentration of both FSH and oestradiol in fluid from large follicles (larger than or equal to 8 mm) was high. During the late follicular phase the large follicles (larger than or equal to 8 mm) contained high amounts of progesterone in addition to oestradiol, low physiological levels of prolactin, and concentrations of LH and FSH about 30 and 60% respectively of those found in plasma. By contrast no large 'active' follicles (larger than or equal to 8 mm) were found during the luteal phase although many contained both LH and FSH. Luteinizing hormone was present in a proportion of small follicles (smaller than 8 mm) during the late follicular and early luteal but not at other stages of the menstrual cycle. It is suggested that a precise sequence of hormonal changes occur within the microenvironment of the developing Graafian follicle; the order in which they occur may be of considerable importance for the growth of that follicle and secretory activity of the granulosa cells both before and after ovulation.

Regulation of immunity in rats by lactogenic and growth hormones.

Abstract: Antibody formation to sheep red blood cells and the development of contact dermatitis in response to dinitrochlorobenzene are impaired in hypophysectomized (Hypo-X) rats. Rat prolactin, rat growth hormone, bovine prolactin, bovine growth hormone, human placental lactogen and human growth hormone all restored the immunological competence of Hypo-X animals. The possible mechanism of action of these hormones on immune reactions is discussed.