Pinealectomy-associated decrease in ribosomal gene activity in rats.

A decrease in ribosomal gene activity is an essential feature of the aging process as it was observed in Alzheimer's disease, in elderly Down's patients and in elderly healthy people. It is well known that aging is also associated with a reduction in melatonin synthesis. We studied 24 male Wistar rats cytogenetically, by using Ag-stained NOR (6 three-month-old rats underwent pinealectomy and were studied after 20 days; 6 control rats of the same age; 6 three-month-old rats underwent pinealectomy and were studied after 8 months; 6 control rats of the same age). Our results indicate that the absence of the pineal gland leads to a decrease in NOR activity. Further studies are necessary to determine if pinealectomy in rats could provide an animal model for aging.