Biomaterial Database

The effect of dopamine on thyrotropin-releasing hormone-induced prolactin secretion in vitro. 1981

K D Fagin, and J D Neill

The direct effects on PRL release of acute changes in dopamine (DA) and TRH concentrations were measured in an in vitro perifusion system. Hemisected anterior pituitaries of lactating rats were perifused with medium that received a coinfusion of DA at 20 ng/ml. These tissues released PRL at 35% of the release rate of controls in the absence of DA. Interruption of the DA coinfusion for 9 min caused a 2-fold increase in PRL release, which was resuppressed when the DA treatment was resumed. During continuous Da exposure, TRH administration (10 ng/ml for 12 min) induced a gradual but slight increase in PRL release. However, when this TRH treatment was administered immediately after the end of the DA interruption, it evoked an immediate 2-fold increase in PRL release to 4 times the initial release rate in the presence of DA. This pronounced effect of TRH after the brief DA interruption was also observed when an 18 min interval was imposed between the two manipulations. During continuous coinfusion of DA at 100 ng/ml, TRH was totally ineffective in eliciting PRL release. However, even after this DA treatment had been interrupted briefly and an increase in PRL release had been evoked, TRH still was not an effective stimulus for PRL release. T was imposed between the two manipulations. During continuous coinfusion of DA at 100 ng/ml, TRH was totally ineffective in eliciting PRL release. However, even after this DA treatment had been interrupted briefly and an increase in PRL release had been evoked, TRH still was not an effective stimulus for PRL release. T was imposed between the two manipulations. During continuous coinfusion of DA at 100 ng/ml, TRH was totally ineffective in eliciting PRL release. However, even after this DA treatment had been interrupted briefly and an increase in PRL release had been evoked, TRH still was not an effective stimulus for PRL release. These data indicate that DA not only can serve as a PRL-inhibiting factor for tonic release of PRL but also may determine by its presence or brief absence, and concentration whether acute release occurs in the presence of a PRL-releasing factor. The direct effect of DA on PRL release and its interference with the action of a PRL-releasing factor appear to be independent of each other.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
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
D010477	Perfusion	Treatment process involving the injection of fluid into an organ or tissue.	Perfusions
D010903	Pituitary Gland, Anterior	The anterior glandular lobe of the pituitary gland, also known as the adenohypophysis. It secretes the ADENOHYPOPHYSEAL HORMONES that regulate vital functions such as GROWTH; METABOLISM; and REPRODUCTION.	Adenohypophysis,Anterior Lobe of Pituitary,Anterior Pituitary Gland,Lobus Anterior,Pars Distalis of Pituitary,Adenohypophyses,Anterior Pituitary Glands,Anterior, Lobus,Anteriors, Lobus,Lobus Anteriors,Pituitary Anterior Lobe,Pituitary Glands, Anterior,Pituitary Pars Distalis
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
D004298	Dopamine	One of the catecholamine NEUROTRANSMITTERS in the brain. It is derived from TYROSINE and is the precursor to NOREPINEPHRINE and EPINEPHRINE. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. A family of receptors (RECEPTORS, DOPAMINE) mediate its action.	Hydroxytyramine,3,4-Dihydroxyphenethylamine,4-(2-Aminoethyl)-1,2-benzenediol,Dopamine Hydrochloride,Intropin,3,4 Dihydroxyphenethylamine,Hydrochloride, Dopamine
D005260	Female		Females
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013973	Thyrotropin-Releasing Hormone	A tripeptide that stimulates the release of THYROTROPIN and PROLACTIN. It is synthesized by the neurons in the PARAVENTRICULAR NUCLEUS of the HYPOTHALAMUS. After being released into the pituitary portal circulation, TRH (was called TRF) stimulates the release of TSH and PRL from the ANTERIOR PITUITARY GLAND.	Protirelin,Thyroliberin,Abbott-38579,Antepan,Proterelin Tartrate,Proterelin Tartrate Hydrate,Protirelin Tartrate (1:1),Relefact TRH,Stimu-TSH,TRH Ferring,TRH Prem,Thypinone,Thyroliberin TRH Merck,Thyrotropin-Releasing Factor,Thyrotropin-Releasing Hormone Tartrate,Abbott 38579,Abbott38579,Hydrate, Proterelin Tartrate,Prem, TRH,Stimu TSH,StimuTSH,TRH, Relefact,Tartrate Hydrate, Proterelin,Thyrotropin Releasing Factor,Thyrotropin Releasing Hormone,Thyrotropin Releasing Hormone Tartrate