Abstract: | The degree of stimulation of adenylcyclase activity, in membranes from immature red blood cells from rats, brought about by isoprenaline, guanylyl-imidodiphosphate and sodium fluoride is strongly dependent on the basal activity of the enzyme. The inversal relationship between basal activity and the maximal degree of stimulation by (--) isoprenaline, shows an apparent seasonal dependence. |