Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1984-10-24
pubmed:abstractText
Adrenocortical function in the tree shrew (Tupaia belangeri) was evaluated by reference to levels of individual corticosteroids as an initial phase in the clarification of the hormonal mechanisms by which stress influences male reproductive function. Corticosteroids were separated with Sephadex LH-20 chromatography and measured by specific radioimmunoassay procedures. Corticosterone was the principal corticosteroid in the peripheral plasma and in unstressed animals the ratio corticosterone:cortisol was 4.5:1 (1000 hr samples). Basal levels of corticosterone and cortisol exhibited parallel diurnal fluctuations with a peak at 0600 hr preceding the onset of daily activity and similar to that described for other diurnally active species. Levels of corticosterone and cortisol were markedly elevated 10 min after either restraint stress applied at various times during the day or ACTH administration to both saline- and dexamethasone-pretreated animals. In each of these experimental situations cortisol showed a greater relative increase from basal levels as compared to corticosterone resulting in a decline in the ratio corticosterone:cortisol. For example, the unstressed ratio of corticosterone (9.1 +/- 0.8 ng/ml) and cortisol (2.0 +/- 0.2 ng/ml) at 1000 hr was 4.5:1. Following 10 min of restraint stress the ratio declined to 1.5:1 (corticosterone, 44.9 +/- 1.4 ng/ml; cortisol, 31.7 +/- 1.3 ng/ml). An increase in cortisol is considered to be an important component of the physiological response to stress by the tree shrew adrenal. It is concluded that the adrenal cortex of the tree shrew normally produces corticosteroids through two pathways and the secretion of both corticosterone and cortisol are responsive to acute ACTH stimulation and feedback inhibition by dexamethasone.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0016-6480
pubmed:author
pubmed:issnType
Print
pubmed:volume
55
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
450-7
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Influence of stress on adrenocortical function in the male tree shrew (Tupaia belangeri).
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't