Age-related differences in concomitant hormone release from the superfused rat adenopituitary

We screened the concomitant release of five adenopituitary (AP) hormones, in vitro, at basal and stimulated conditions, in young and aged (2-3 and 25 months old, respectively) male Fischer 344 rats. The APs of aged rats exhibited significantly higher basal and total release of prolactin, but lower release of luteinizing hormone, follicle-stimulating hormone, thyroid-stimulating hormone and growth hormone than those of young rats. The APs of aged rats did not respond to high K+ depolarization by an increased release of any of the studied hormones, whereas the APs of young rats did release a significant amount in all instances. The results indicate marked age-related alterations affecting the release of the hormones, detectable even in the isolated AP alone.