Linked Life Data

6256160

Source:http://linkedlifedata.com/resource/pubmed/id/6256160

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1981-3-27
pubmed:abstractText
A perifusion system has been developed in which a dose-dependent response of isolated Leydig tumor cells to steroidogenic stimuli, as assessed by the rates of steroid production, can be measured as a function of time. In response to a continuous perifusion for 340 min with a saturating concentration of hCG, ovine LH (oLH), cholera toxin, or 8-Br-cAMP, there is a rapid increase in the rate of progesterone production, which reaches a maximum about 100 min after the onset of stimulus in the medium and then declines to a rate somewhat higher than basal. Thus cholera toxin and 8-Br-cAMP as well as hCG and oLH are able to desensitize the Leydig tumor cells to further stimulation by the same agent. Although a 10-min pulse of a saturating concentration of hCG yields the same steroidogenic response as that elicited by continuous perifusion with saturating hCG, a pulse of a saturating concentration of oLH yields a steroidogenic response only when oLH is maintained in the perifusate. These data establish a substantial difference in the actions of hCG and oLH. The results could be explained by the higher apparent affinity of hCG for the gonadotropin receptor, such that, upon removal of hormone from the perifusate, oLH would be more readily eluted from the receptor. These findings support the hypothesis that oLH and hCG exert their stimulatory effects only while bound to the cell surface. (Endocrinology 108: 632, 1981)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
108
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
632-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1981
pubmed:articleTitle
The dynamics of the steroidogenic response of perifused Leydig tumor cells to human chorionic gonadotropin, ovine luteinizing hormone, cholera toxin, and adenosine 3',5'-cyclic monophosphate.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't