Age-related changes of cyclic nucleotide levels in rat brain regions

Abstract Cyclic AMP and cyclic GMP levels were measured in seven brain areas of rats 4–30 months old. In several brain areas cyclic nucleotides were higher in 4-month-old rats than in rats 12 months old or older. On the other hand, in the hypothalamus cyclic GMP levels were decreased only in 30-month-old rats, a pattern of onset similar to that of senile deterioration.