Linked Life Data

3428560

Source:http://linkedlifedata.com/resource/pubmed/id/3428560

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1988-3-15
pubmed:abstractText
Histochemical assays, hormonal quantitation, and steroid biosynthetic studies were carried out with adrenal glands obtained from four stranded whales of two different species (Kogia breviceps and Mesoplodon europaeus), and selected comparisons were made with the results of similar studies of adrenals from terrestrial mammals (man, beef, rat). Histochemical chemical assays of the whale glands for succinic dehydrogenase activity (SDA) showed an intense SDA-positive reaction in the peripheral cortex, and an SDA-negative central medulla, a pattern similar to that found in terrestrial mammals; the whale adrenals, however, demonstrated a markedly pseudolobulated appearance because of a festooned corticomedullary junction. On radioimmunoassay of preformed cortical steroid hormones, corticosterone (B) exceeded cortisol (F) levels by a factor of 3 in the whale adrenals and aldosterone (Aldo) concentrations were 20-100 times lower than in the terrestrial mammals studied. HPLC determinations of preformed medullary catecholamines showed that, contrary to the findings in the terrestrial mammals studied, norepinephrine predominated over epinephrine and the levels of dopamine were much higher in the whale adrenals. In vitro, surviving sections of whale adrenals elaborated B from endogenous substrates, but not F or Aldo. Incubations of subcellular fractions of the whale adrenals with 14C-labeled precursors resulted in the isolation of several steroid intermediates (pregnenolone, progesterone, deoxycorticosterone) as well as the glucocorticoid end-product B, but again without evidence of the formation of either F or Aldo. In keeping with studies in terrestrial mammals, the enzymatic reactions involved in the conversion of [14C]cholesterol to B occurred under aerobic conditions, required the presence of an exogenous NADPH-generating system, and had identical subcellular localization in the whale adrenals. The process of steroid biosynthesis thus appears generally similar in aquatic and terrestrial mammals. It is possible that some of the unusual findings in the whale adrenals studies here may be related to the profound stress of stranding experienced by these marine mammals.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0016-6480
pubmed:author
pubmed:issnType
Print
pubmed:volume
68
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
293-303
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
The adrenal gland of stranded whales (Kogia breviceps and Mesoplodon europaeus): morphology, hormonal contents, and biosynthesis of corticosteroids.
pubmed:affiliation
Research Service, Veterans Administration Medical Center, Miami, Florida 33125.
pubmed:publicationType
Journal Article, Comparative Study, In Vitro