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INFLUENCE OF DIVALENT CATIONS ON REGULATION OF CYCLIC GMP AND CYCLIC AMP LEVELS IN BRAIN TISSUE
Author(s) -
Ferrendelli J. A.,
Rubin E. H.,
Kinscherf Dorothy A.
Publication year - 1976
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1976.tb04446.x-i1
Subject(s) - cyclic gmp , divalent , chemistry , biophysics , medicine , endocrinology , biochemistry , biology , organic chemistry , enzyme
—Depolarizing concentrations of K + elevate levels of both adenosine 3′,5′monophosphate (cyclic AMP) and guanosine 3′,5′monophosphate (cyclic GMP) in incubated slices of mouse cerebellum. Calcium is an essential requirement for the K + ‐induced accumulation of cyclic GMP. Barium and Sr 2+ , but not Mn 2+ or Co 2+ , can substitute for Ca 2+ in this process. Relatively high concentrations of Mg 2+ inhibit the effect of Ca 2+ on K + ‐induced accumulation of cyclic GMP. In contrast, depolarizing concentrations of K + are capable of elevating cyclic AMP levels in brain slices suspended in media containing Mg 2+ and no other divalent cations. High concentrations of Ca 2+ (1 m m or greater) augment this Mg 2+ ‐dependent, K + ‐induced accumulation of cyclic AMP, however. Strontium and Mn 2+ , but not Ba 2+ or Co 2+ , can substitute for Ca 2+ in this process, and high concentrations of Mg 2+ are not inhibitory. The divalent cation ionophore, A‐23187 (10 μ m ), in the presence of extracellular Ca 2+ elevates the level of cyclic GMP, but not cyclic AMP, in incubated mouse cerebellum slices. The results of this study indicate that intracellular Ca 2+ concentration is a major factor regulating cyclic GMP levels in brain. In addition the present results suggest that, in brain tissue, depolarization‐induced accumulation of cyclic GMP, but not cyclic AMP, is closely linked to some Ca 2+ ‐dependent mechanism(s) mediating release of intracellular substances.