title: The effects of endogenous and exogenous sex hormones and of maturation on cGMP phosphodiesterase activity in the brain.
abstract: Kinetic analysis of cGMP phosphodiesterase activity in the rat brain indicated that Km values did not differ significantly with sex, age (1 to 270 days old), or brain area (amygdala, cerebellum, cerebral cortex, hypothalamus, thalamus, reticular formation). There was no dimorphism in enzyme activity between normal or artificially mimicked gender, nor was there any significant variation in activity following short or long term alterations of endogenous levels of gonadal hormones in any of the brain regions investigated. Highest activity was observed in cerebral cortex and amygdala. Maturation caused a significant increase in enzyme activity, the adult levels being reached by the 38th to 40th day of life.
mesh_terms: D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000032:analysis*; D000262:Adenylyl Cyclases / Q000032:analysis; D000367:Age Factors; D000818:Animals; D001921:Brain / Q000201:enzymology*; D002369:Castration; D004971:Estrus; D005260:Female; D012739:Gonadal Steroid Hormones / Q000494:pharmacology / Q000502:physiology*; D007700:Kinetics; D008297:Male; D011247:Pregnancy; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D012739:Gonadal Steroid Hormones; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D000262:Adenylyl Cyclases