Bureau of Biological Research, Rutgers University, New Brunswick, New Jersey 08903, U.S.A.
(Received 24 March 1977)
Dehydrogenase enzyme activity linked to NADP has been implicated in the regulation of steroidogenesis in the adrenal gland and ovary (McKerns, 1964, 1965). Furthermore, glucose6-phosphate dehydrogenase (G6PD) activity increases after trophic hormone stimulation, suggesting a metabolic role in the stimulated cells (Castracane & Leathern, 1976). However, little consideration has been given to G6PD as a metabolic marker in steroidogenic organs in relation to ageing. Trout (1974) found G6PD activity to be greater in the adrenal glands of female than of male Wistar rats, but observed no change with age up to 19 months, whereas Stewart & Hunter (1969) recorded a decline in both adrenal and ovarian G6PD activity in 24-month-old Long-Evans rats. A re-examination of G6PD activity in the adrenal glands, testes and ovaries (which exhibit a decline in the formation of follicles: Leathem