Lipid droplets in the secretory response of Leydig cells of normal and hCG-treated rats.
Prolonged (7-day) hCG infusion caused a remarkable hypertrophy of rat Leydig cells, coupled with a notable enhancement of their basal and stimulated testosterone production in vitro. It also provoked a conspicuous accumulation of lipid droplets in the cytoplasm of hypertrophic cells. The administration of 4-aminopyrazolo-pyrimidine (4APP), at a dose causing a significant hypocholesterolaemia, did not affect the morphology and function of Leydig cells in normal rats. Conversely, in chronically hCG-infused animals, 4APP reversed lipid-droplet accumulation and significantly depressed stimulated testosterone production. The following conclusions are drawn: 1) chronic hCG treatment enhances the ability of rat Leydig cells to take-up exogenous cholesterol from circulating lipoproteins, and to store it in lipid droplets as a reserve material; 2) lipid-droplet stored cholesterol is employed only in the case of intense acute stimulation, since, under basal conditions, endogenous cholesterol synthesis is able to meet the requirements for testosterone production alone.
Andreis
P G
PG
Department of Anatomy, University of Padua, Italy.
Cavallini
L
L
Mazzocchi
G
G
Meneghelli
V
V
Nussdorfer
G G
GG
D000225:Adenine / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D000924:Anticholesteremic Agents / Q000494:pharmacology; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D002479:Inclusion Bodies / Q000648:ultrastructure; D007985:Leydig Cells / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D050356:Lipid Metabolism; D008297:Male; D008854:Microscopy, Electron; D051381:Rats; D011919:Rats, Inbred Strains
D000924:Anticholesteremic Agents; D006063:Chorionic Gonadotropin; C004420:4-aminopyrazolo(3,4-d)pyrimidine; D000225:Adenine