BIOMAT Database Logo BIOMAT Database Logo

Alpha 2 and beta adrenoceptors in the mediobasal hypothalamus and alpha 2 adrenoceptors in the preoptic-anterior hypothalamus stimulate prolactin secretion in the conscious male rat. 1993

R Kapoor, and I M Chapman, and J O Willoughby
Centre for Neuroscience, Flinders University and Medical Centre, Adelaide, South Australia.

Plasma prolactin concentrations were measured in unanaesthetized male rats before and after stereotaxic microinjection of adrenergic agents into the mediobasal and preoptic-anterior hypothalamus. In the mediobasal hypothalamus injection of the alpha 2 agonist clonidine produced a dose-dependent increase in prolactin secretion over the dose range 0.1 to 10 nmoles, the stimulation due to 1 nmole being blocked by idazoxan (alpha 2 antagonist). Stimulation of prolactin release was also caused by isoprenaline (beta agonist) and was significantly reduced by the beta antagonist propranolol. The beta 2 agonist salbutamol was also effective in stimulating prolactin secretion. However, the adrenergic agonists, noradrenaline (mixed alpha and beta), phenylephrine (alpha 1) and tyramine (sympathomimetic) failed to affect prolactin secretion. In the preoptic-anterior hypothalamus clonidine caused a dose-dependent increase in prolactin secretion over the dose range 0.001 to 10 nmoles, the stimulation due to 0.1 nmole being abolished by idazoxan. While prolactin levels were significantly elevated by noradrenaline and tyramine, phenylephrine was ineffective. We conclude that the activation of alpha 2 and beta 2 adrenoceptors in the mediobasal hypothalamus and of alpha 2 adrenoceptors in the preoptic-anterior hypothalamus, on or near prolactin-regulating neurons, results in increased prolactin secretion. An alpha 1 inhibitory action in the mediobasal hypothalamus has however not been ruled out. Adrenergic inputs in the preoptic-anterior hypothalamus appear to exert a predominant facilitatory effect on prolactin secretion.

UI MeSH Term Description Entries
D007032 Hypothalamus, Anterior The front portion of the HYPOTHALAMUS separated into the preoptic region and the supraoptic region. The preoptic region is made up of the periventricular GRAY MATTER of the rostral portion of the THIRD VENTRICLE and contains the preoptic ventricular nucleus and the medial preoptic nucleus. The supraoptic region contains the PARAVENTRICULAR HYPOTHALAMIC NUCLEUS, the SUPRAOPTIC NUCLEUS, the ANTERIOR HYPOTHALAMIC NUCLEUS, and the SUPRACHIASMATIC NUCLEUS. Hypothalamus, Supraoptic,Anterior Hypothalamic Commissure,Anterior Hypothalamic Decussation of Ganser,Anteroventral Periventricular Nucleus,Anterior Hypothalamic Commissures,Anterior Hypothalamus,Commissure, Anterior Hypothalamic,Commissures, Anterior Hypothalamic,Hypothalamic Commissure, Anterior,Hypothalamic Commissures, Anterior,Nucleus, Anteroventral Periventricular,Periventricular Nucleus, Anteroventral,Supraoptic Hypothalamus
D007033 Hypothalamus, Middle Middle portion of the hypothalamus containing the arcuate, dorsomedial, ventromedial nuclei, the TUBER CINEREUM and the PITUITARY GLAND. Hypothalamus, Medial,Intermediate Hypothalamic Region,Hypothalamic Region, Intermediate,Hypothalamic Regions, Intermediate,Intermediate Hypothalamic Regions,Medial Hypothalamus,Middle Hypothalamus,Region, Intermediate Hypothalamic,Regions, Intermediate Hypothalamic
D007275 Injections, Intravenous Injections made into a vein for therapeutic or experimental purposes. Intravenous Injections,Injection, Intravenous,Intravenous Injection
D008297 Male Males
D008845 Microinjections The injection of very small amounts of fluid, often with the aid of a microscope and microsyringes. Microinjection
D011301 Preoptic Area Region of hypothalamus between the ANTERIOR COMMISSURE and OPTIC CHIASM. Area Preoptica,Lateral Preoptic Area,Medial Preoptic Area,Preoptic Nuclei,Area Preopticas,Area, Lateral Preoptic,Area, Medial Preoptic,Area, Preoptic,Areas, Lateral Preoptic,Areas, Medial Preoptic,Areas, Preoptic,Lateral Preoptic Areas,Medial Preoptic Areas,Nuclei, Preoptic,Nucleus, Preoptic,Preoptic Area, Lateral,Preoptic Area, Medial,Preoptic Areas,Preoptic Areas, Lateral,Preoptic Areas, Medial,Preoptic Nucleus,Preoptica, Area,Preopticas, Area
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
D011942 Receptors, Adrenergic, alpha One of the two major pharmacological subdivisions of adrenergic receptors that were originally defined by the relative potencies of various adrenergic compounds. The alpha receptors were initially described as excitatory receptors that post-junctionally stimulate SMOOTH MUSCLE contraction. However, further analysis has revealed a more complex picture involving several alpha receptor subtypes and their involvement in feedback regulation. Adrenergic alpha-Receptor,Adrenergic alpha-Receptors,Receptors, alpha-Adrenergic,alpha-Adrenergic Receptor,alpha-Adrenergic Receptors,Receptor, Adrenergic, alpha,Adrenergic alpha Receptor,Adrenergic alpha Receptors,Receptor, alpha-Adrenergic,Receptors, alpha Adrenergic,alpha Adrenergic Receptor,alpha Adrenergic Receptors,alpha-Receptor, Adrenergic,alpha-Receptors, Adrenergic
D011943 Receptors, Adrenergic, beta One of two major pharmacologically defined classes of adrenergic receptors. The beta adrenergic receptors play an important role in regulating CARDIAC MUSCLE contraction, SMOOTH MUSCLE relaxation, and GLYCOGENOLYSIS. Adrenergic beta-Receptor,Adrenergic beta-Receptors,Receptors, beta-Adrenergic,beta Adrenergic Receptor,beta-Adrenergic Receptor,beta-Adrenergic Receptors,Receptor, Adrenergic, beta,Adrenergic Receptor, beta,Adrenergic beta Receptor,Adrenergic beta Receptors,Receptor, beta Adrenergic,Receptor, beta-Adrenergic,Receptors, beta Adrenergic,beta Adrenergic Receptors,beta-Receptor, Adrenergic,beta-Receptors, Adrenergic
D004305 Dose-Response Relationship, Drug The relationship between the dose of an administered drug and the response of the organism to the drug. Dose Response Relationship, Drug,Dose-Response Relationships, Drug,Drug Dose-Response Relationship,Drug Dose-Response Relationships,Relationship, Drug Dose-Response,Relationships, Drug Dose-Response

Related Publications

R Kapoor, and I M Chapman, and J O Willoughby
Adrenoceptors in the preoptic-anterior hypothalamic area stimulate secretion of prolactin but not growth hormone in the male rat.
May 1986, Brain research bulletin,
R Kapoor, and I M Chapman, and J O Willoughby
Activation of opioid receptors in the mediobasal hypothalamus stimulates prolactin secretion in the conscious rat.
June 1990, Journal of neuroendocrinology,
R Kapoor, and I M Chapman, and J O Willoughby
Effects of placing micro-implants of melatonin in the mediobasal hypothalamus and preoptic area on the secretion of prolactin and beta-endorphin in rams.
September 1992, The Journal of endocrinology,
R Kapoor, and I M Chapman, and J O Willoughby
Catecholestrogens affect catecholamine turnover rates in the anterior part of the mediobasal hypothalamus and medial preoptic area in the male and female castrated rat.
January 1983, Neuroendocrinology,
R Kapoor, and I M Chapman, and J O Willoughby
[Neuron projection from the preoptic region and the anterior hypothalamic area towards the mediobasal hypothalamus in the male guinea pig].
September 1975, Comptes rendus hebdomadaires des seances de l'Academie des sciences. Serie D: Sciences naturelles,
R Kapoor, and I M Chapman, and J O Willoughby
Activation of mu opioid receptors in the pre-optic-anterior hypothalamus releases prolactin in the conscious male rat.
August 1991, Neuropeptides,
R Kapoor, and I M Chapman, and J O Willoughby
Domperidone stimulates prolactin secretion in rats with complete destruction of the mediobasal hypothalamus.
January 1997, Brain research bulletin,
R Kapoor, and I M Chapman, and J O Willoughby
Anterior pituitary prolactin release in vitro after interruption of anterolateral neural connections of the mediobasal hypothalamus in male rats.
October 1984, Brain research,
R Kapoor, and I M Chapman, and J O Willoughby
[Changes in sexual functioning in the male rat after total or anterior deafferentation of the mediobasal hypothalamus].
March 1986, Fiziologicheskii zhurnal SSSR imeni I. M. Sechenova,
R Kapoor, and I M Chapman, and J O Willoughby
Prolactin inhibiting activity of dopamine-free subcellular fractions from rat mediobasal hypothalamus.
January 1977, Neuroendocrinology,
Copied contents to your clipboard!