The effect of chronic luteinizing hormone treatment on adult rat Leydig cells.

摘要

Two groups each of 5 sexually mature male Sprague-Dawley rats were used; untreated controls and rats implanted with a subdermal LH-filled Alzet mini osmotic pumps (delivering 24μg LH per day). After 2 weeks of LH treatment, testes of these rats were fixed by 2.5% glutaraldehyde in cacodylate buffer and processed and embedded in epon-araldite for light and electron microscopy and electron microscopic immunocytochemistry. Isolated and purified Leydig cells were used to determine the LH-stimulated (100 ng/ml) testosterone secretory capacity per Leydig cell in vitro. After 2 weeks of LH treatment, Leydig cell number per testis and the average volume showed a 2-fold increase over controls. All organelles, except lipid droplets, were increased (P<0.05)2-fold in volume per Leydig cell. Testosterone secretory capacity per Leydig cell was increased approximately 6-fold in the LH-treated group. Immunolabelling showed that intraperoxisomal sterol carrier protein-2 (SCP2) content was greater (P<0.05) and the catalase content was lower (P<0.05) in LH-treated rats compared to controls. Immunoblots showed that the total SCP2 content per cell was greater and the catalase content per cell was similar in treated rats compared to controls.