Linked Life Data

1333363

Source:http://linkedlifedata.com/resource/pubmed/id/1333363

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1993-1-7
pubmed:abstractText
The morphological counterpart of the well-known age-dependent marked impairment of glucocorticoid secretion of rat adrenals was investigated by use of morphometric techniques. For this purpose 4-, 8-, 16- and 24-month-old rats were studied. Despite the notable lowering of both basal and ACTH-stimulated production of corticosterone by collagenase-dispersed inner adrenocortical cells, ACTH and corticosterone plasma concentrations displayed significant increases with ageing. Zona fasciculata (ZF) and zona reticularis (ZR) showed a notable hypertrophy in aged rats, which was due to rises in both the average volume and number of their parenchymal cells. The hypertrophy of ZF and ZR cells was in turn associated with increase in the volume of the mitochondrial compartment and proliferation of smooth endoplasmic reticulum, i.e., the two organelles involved in steroid-hormone synthesis. All these morphologic changes, conceivably due to the chronic exposure to high levels of circulating ACTH, are interpreted as a response enabling ZF and ZR to compensate for their age-dependent lowering in glucocorticoid secretion. Stereology also demonstrated that ZF and ZR cells underwent a striking age-related lipid-droplet repletion. Lipid droplets are the intracellular stores of cholesterol esters, the obligate precursors of steroid hormones in rats. This finding is in keeping with the contention that the mechanism underlying the age-dependent decline in rat-adrenal glucocorticoid secretion mainly involves impairments of the utilization of intracellular cholesterol previous to its intramitochondrial transformation to pregnenolone.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0302-766X
pubmed:author
pubmed:issnType
Print
pubmed:volume
270
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
265-72
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
The effects of ageing on the morphology and function of the zonae fasciculata and reticularis of the rat adrenal cortex.
pubmed:affiliation
Department of Anatomy, University of Padua, Italy.
pubmed:publicationType
Journal Article