Metabolism of high density lipoproteins reconstituted with (TH)cholesteryl ester and ( UC)cholesterol in the rat, with special reference to the ovary

Journal Article · Thu Aug 01 00:00:00 EDT 1985 · Endocrinology; (United States)

OSTI ID:6085826

Nestler, J E; Bamberger, M; Rothblat, G H; Strauss, III, J F

In order to study the metabolism of high density lipoprotein (HDL)-carried sterol in the rat, human HDL was reconstituted with ( UC)cholesterol and (TH)cholesteryl ester. After iv injection into immature PMSG-human CG primed rats pretreated with 4-aminopyrazolopyrimidine and aminoglutethimide, there was time-dependent accumulation of TH and UC in various organs which reached a maximum by 15-90 min. On a milligram wet weight basis, uptake of TH and UC was greatest in the adrenals, next in ovaries, followed by the liver, with little uptake by kidneys and spleen. On an organ basis, accumulation was greatest by the liver. Coadministration of excess unlabeled HDL, but not human low density lipoprotein, reduced accumulation of radioactivity by the ovaries and adrenals by 60%, indicating a specific and saturable uptake process. Granulosa cells cultured in lipoprotein-deficient medium with reconstituted HDL formed TH- and UC-labeled 20 alpha-hydroxypregn-4-en-3-one. Over a 24-h period, utilization of both ( UC)cholesterol and (TH)cholesteryl ester was linear, but rates of utilization of the two sterol moieties were not parallel. Lysosomotropic agents had no effect on utilization of either free or esterified cholesterol for steroidogenesis but reduced degradation of SVI-labeled low density lipoprotein apoprotein. These findings lend further support to the concept of a distinct HDL pathway in steroidogenic cells of the rat.

• Research Organization: Univ. of Pennsylvania, Philadelphia
• OSTI ID: 6085826
• Journal Information: Endocrinology; (United States), Vol. 2
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
CARBON 14 COMPOUNDS
TRACER TECHNIQUES
LIPOPROTEINS
KINETICS
METABOLISM
TISSUE DISTRIBUTION
TRITIUM COMPOUNDS
ADRENAL GLANDS
CHOLESTEROL
OVARIES
PROGESTERONE
RATS
ANIMALS
BODY
DISTRIBUTION
ENDOCRINE GLANDS
FEMALE GENITALS
GLANDS
GONADS
HORMONES
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
KETONES
LABELLED COMPOUNDS
LIPIDS
MAMMALS
ORGANIC COMPOUNDS
ORGANS
PREGNANES
PROTEINS
RODENTS
STEROID HORMONES
STEROIDS
STEROLS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques