Linked Life Data

3004910

Source:http://linkedlifedata.com/resource/pubmed/id/3004910

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1986-4-24
pubmed:abstractText
The effect of conditioned vs. fresh culture medium on the dopaminergic inhibition of TSH and PRL secretion by primary cultures of male rat anterior pituitary cells has been studied. In the presence of conditioned medium (that had been in contact with the cells over the 3-day culture period) 10(-6) M dopamine (DA) inhibited PRL secretion by 50% and TSH secretion by 30%. After 4 h of incubation with fresh medium 10(-6) M DA still inhibited PRL secretion by 50% but increased TSH release by 20%. TSH release was rapid and could be prevented by 10(-6) M prazosin, an alpha 1 adrenoreceptor antagonist. Fresh medium did not alter TRH induced TSH release. In parallel cultures and under identical conditions fresh medium reduced [3H]dihydroergocryptine (DHE) binding to DA receptors from 2.5 +/- 0.4 fmol/10(5) cells to 0.95 +/- 0.3 fmol/10(5) cells (means +/- SEM, n = 5, P less than 0.001). The effect of fresh medium was dose dependent against the dopaminergic inhibition of TSH secretion and against DA receptor binding. If 1 mU TSH was included, in fresh medium, the dopaminergic inhibition of TSH secretion remained unchanged and [3H]DHE binding to DA receptors did not fall. The rank order of potency of thyroid stimulators was bovine TSH (21 U/mg) greater than semipurified bovine TSH (Thytropar, 1.4 U/mg) greater than endogenous rat TSH (0.03 U/mg expressed as NIADDK-rat TSH-RP2) greater than Graves' immunoglobulin G (0.01 U/mg) when either DA or bromocriptine was used as the dopaminergic agonist. When anterior pituitary cells from hypothyroid rats were examined, the effects of culture medium on the dopaminergic inhibition of TSH and on DA receptor binding were approximately twice those observed in normal cells, but the inclusion of 1 mU TSH in the fresh medium completely prevented the loss of DA function and binding. PRL, human CG, ACTH, insulin, glucagon, and heat-inactivated TSH were unable to prevent the effect of medium replacement on dopaminergic inhibition of TSH and DA receptor binding. The data suggest a mechanism whereby TSH may control its own secretion via DA.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
118
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1319-26
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:3004910-Adrenocorticotropic Hormone, pubmed-meshheading:3004910-Animals, pubmed-meshheading:3004910-Bromocriptine, pubmed-meshheading:3004910-Chorionic Gonadotropin, pubmed-meshheading:3004910-Culture Media, pubmed-meshheading:3004910-Dopamine, pubmed-meshheading:3004910-Dose-Response Relationship, Drug, pubmed-meshheading:3004910-Drug Interactions, pubmed-meshheading:3004910-Glucagon, pubmed-meshheading:3004910-Hot Temperature, pubmed-meshheading:3004910-Hypothyroidism, pubmed-meshheading:3004910-Insulin, pubmed-meshheading:3004910-Male, pubmed-meshheading:3004910-Pituitary Gland, Anterior, pubmed-meshheading:3004910-Prolactin, pubmed-meshheading:3004910-Rats, pubmed-meshheading:3004910-Rats, Inbred Strains, pubmed-meshheading:3004910-Receptors, Dopamine, pubmed-meshheading:3004910-Thyrotropin, pubmed-meshheading:3004910-Time Factors
pubmed:year
1986
pubmed:articleTitle
Thyrotropin regulates thyrotroph responsiveness to dopamine in vitro.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't