A comparison of rat and hamster preovulatory follicles: an examination of differences in morphology and enzyme activity using qualitative and quantitative analyses.

The structure and enzymatic content of rat and hamster preovulatory follicles were examined using morphologic, qualitative, and quantitative cytochemical techniques. Interfollicular structure in both types was similar but lipid droplet distribution differed. The rat theca contained many more droplets than the hamster, while the hamster membrana granulosa contained more droplets than the rat. delta 5-3 beta-hydroxysteroid dehydrogenase (3 beta OHD) activity and glucose-6-phosphate dehydrogenase (G-6-PD) Types IH and IIH generation were measured using quantitative cytochemistry. Rat theca and granulosa contained more 3 beta OHD activity than found in comparable regions in hamster. G-6-PD Type IH and Type IIH generation were the same in comparable regions of rat and hamster, but in rat there was more Type IIH than IH, while the converse existed in hamster. These differences and their relationship to follicular steroid production are discussed.