title: Evidence that Leydig precursors localize in immature band two cells isolated on Percoll gradients.
abstract: The present studies examined responses to hCG and/or insulin of 3 beta-hydroxy-5-ene-steroid dehydrogenase and steroid 5----4-ene-isomerase activity (3 beta-HSD) in cultured Band 2 and Band 3 cells from 25- to 40-day-old rats isolated on Percoll gradients. In Band 2 cells, from 25-day-old rats enzyme activity increased about 3- and 2.5-fold, after 6 days of exposure to hCG or insulin, respectively. However, hCG did not stimulate enzyme activity in Band 2 cells from 30-, 35- and 40-day-old animals, and responses to insulin alone or insulin plus hCG declined with age. In Band 3 cells only insulin increased enzyme activity at each age. Neither hCG or insulin altered DNA levels in Band 2 or Band 3 cells, suggesting that increased activity in Band 2 cells from 25-day-old rats was not due to cellular replication. However, hCG increased the number of cells staining positive for 3 beta-HSD about 4-fold in Band 2 cells from 25-day-old rats. Insulin did not increase the number of positive staining cells in Band 2 and Band 3 cells from 25-day-old rats, suggesting that its major effect was to increase enzyme activity in existing cells. These results suggest that during a limited period of maturation precursor cells in Band 2, which are undetected by histochemical staining for 3 beta-HSD, can be converted to Leydig cells in culture by hCG.
authors.affiliation: Research Service, Dorn Veterans' Hospital, Columbia, SC.
authors.forename: E P
authors.initials: EP
authors.lastname: Murono
authors.forename: A L
authors.initials: AL
authors.lastname: Washburn
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002498:Centrifugation; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D004247:DNA / Q000378:metabolism; D007328:Insulin / Q000494:pharmacology*; D007985:Leydig Cells / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology; D008297:Male; D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism*; D011205:Povidone; D011375:Progesterone Reductase / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012822:Silicon Dioxide; D013234:Stem Cells / Q000166:cytology*; D013251:Steroid Isomerases / Q000235:genetics / Q000378:metabolism*
chemical_list: C021425:3 beta-hydroxysteroid oxidoreductase-delta(5) 3-ketosteroid isomerase; D006063:Chorionic Gonadotropin; D007328:Insulin; D009097:Multienzyme Complexes; C016039:Percoll; D012822:Silicon Dioxide; D004247:DNA; D011375:Progesterone Reductase; D013251:Steroid Isomerases; D011205:Povidone