Biomaterial Database

Effects of porcine hypothalamic extract on prolactin release in the rat. 1975

J E Milmore, and R P Reece

The effect of crude extract of porcine stalk-medium eminence (SME) on release of prolactin, measured by radioimmunoassay, has been studied in the rat. In male rats, intravenous administration of 3-4 SME equivalents caused an acute increase in serum prolactin levels. This prolactin-releasing factor (PRF) effect was observed in rats anesthetized with either pentobarbital or ether, and was not dependent upon estrogen pretreatment of the animals. Prolactin release was not seen with doses of 5 or 50 mug of synthetic thyrotropin-releasing hormone (TRH). The presence of porcine SME extract enhanced the release of prolactin by male rat pituitary halves incubated for 2 h in Medium 199. This effect was observed whether or not pituitary donors were pretreated with estrogen. In contrast to the observations in male animals, administration of 3 porcine SME equivalents to lactating rats separated from their litters for 4 h did not elevate serum prolactin. Failure to observe PRF activity could not be accounted for by the anesthetic employed. In vitro, porcine SME extract did not stimulate release of prolactin by pituitaries from lactating rats. Intraperitoneal injection of extract of 3 porcine SME equivalents inhibited the increase in serum prolactin which occurs when lactating rats are reunited with their litters for 30 min after 4 h of separation. These results are consistent with the concept that suckling-induced prolactin release is accomplished by cessation of discharge of a prolactin release-inhibiting factor (PIF). Furthermore, since effects of PRF were observed only in male rats, it is also concluded that the physiological state of animals treated with hypothalamic extracts is an important factor in determining responsiveness to either PIF or PRF.

UI	MeSH Term	Description	Entries
D007031	Hypothalamus	Ventral part of the DIENCEPHALON extending from the region of the OPTIC CHIASM to the caudal border of the MAMMILLARY BODIES and forming the inferior and lateral walls of the THIRD VENTRICLE.	Lamina Terminalis,Preoptico-Hypothalamic Area,Area, Preoptico-Hypothalamic,Areas, Preoptico-Hypothalamic,Preoptico Hypothalamic Area,Preoptico-Hypothalamic Areas
D007774	Lactation	The processes of milk secretion by the maternal MAMMARY GLANDS after PARTURITION. The proliferation of the mammary glandular tissue, milk synthesis, and milk expulsion or let down are regulated by the interactions of several hormones including ESTRADIOL; PROGESTERONE; PROLACTIN; and OXYTOCIN.	Lactation, Prolonged,Milk Secretion,Lactations, Prolonged,Milk Secretions,Prolonged Lactation,Prolonged Lactations
D008297	Male		Males
D008426	Maternal Deprivation	Prolonged separation of the offspring from the mother.	Deprivation, Maternal,Deprivations, Maternal,Maternal Deprivations
D008473	Median Eminence	Raised area at the infundibular region of the HYPOTHALAMUS at the floor of the BRAIN, ventral to the THIRD VENTRICLE and adjacent to the ARCUATE NUCLEUS OF HYPOTHALAMUS. It contains the terminals of hypothalamic neurons and the capillary network of hypophyseal portal system, thus serving as a neuroendocrine link between the brain and the PITUITARY GLAND.	Eminentia Mediana,Medial Eminence,Eminence, Medial,Eminence, Median,Eminences, Medial,Eminentia Medianas,Medial Eminences,Mediana, Eminentia,Medianas, Eminentia
D010424	Pentobarbital	A short-acting barbiturate that is effective as a sedative and hypnotic (but not as an anti-anxiety) agent and is usually given orally. It is prescribed more frequently for sleep induction than for sedation but, like similar agents, may lose its effectiveness by the second week of continued administration. (From AMA Drug Evaluations Annual, 1994, p236)	Mebubarbital,Mebumal,Diabutal,Etaminal,Ethaminal,Nembutal,Pentobarbital Sodium,Pentobarbital, Monosodium Salt,Pentobarbitone,Sagatal,Monosodium Salt Pentobarbital
D011247	Pregnancy	The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.	Gestation,Pregnancies
D011388	Prolactin	A lactogenic hormone secreted by the adenohypophysis (PITUITARY GLAND, ANTERIOR). It is a polypeptide of approximately 23 kD. Besides its major action on lactation, in some species prolactin exerts effects on reproduction, maternal behavior, fat metabolism, immunomodulation and osmoregulation. Prolactin receptors are present in the mammary gland, hypothalamus, liver, ovary, testis, and prostate.	Lactogenic Hormone, Pituitary,Mammotropic Hormone, Pituitary,Mammotropin,PRL (Prolactin),Hormone, Pituitary Lactogenic,Hormone, Pituitary Mammotropic,Pituitary Lactogenic Hormone,Pituitary Mammotropic Hormone
D011863	Radioimmunoassay	Classic quantitative assay for detection of antigen-antibody reactions using a radioactively labeled substance (radioligand) either directly or indirectly to measure the binding of the unlabeled substance to a specific antibody or other receptor system. Non-immunogenic substances (e.g., haptens) can be measured if coupled to larger carrier proteins (e.g., bovine gamma-globulin or human serum albumin) capable of inducing antibody formation.	Radioimmunoassays
D002540	Cerebral Cortex	The thin layer of GRAY MATTER on the surface of the CEREBRAL HEMISPHERES that develops from the TELENCEPHALON and folds into gyri and sulci. It reaches its highest development in humans and is responsible for intellectual faculties and higher mental functions.	Allocortex,Archipallium,Cortex Cerebri,Cortical Plate,Paleocortex,Periallocortex,Allocortices,Archipalliums,Cerebral Cortices,Cortex Cerebrus,Cortex, Cerebral,Cortical Plates,Paleocortices,Periallocortices,Plate, Cortical