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Role of Calmodulin and Protein Kinase C in Astrocytic Cell Volume Regulation
Author(s) -
Bender Alex S.,
Neary Joseph T.,
Blicharska Janina,
Norenberg LuzOliva B.,
Norenberg Michael D.
Publication year - 1992
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.1471-4159.1992.tb10064.x
Subject(s) - protein kinase c , protein kinase a , kinase , microbiology and biotechnology , calmodulin , chemistry , biology , biochemistry , enzyme
We investigated the role of Ca 2+ ‐dependent protein kinases in the regulation of astrocytic cell volume. Calmodulin (CaM) antagonists were used to inhibit CaM and thus Ca 2+ /CaM‐dependent protein kinase. The effect of these inhibitors as well as activators and inhibitors of protein kinase C (PKC) on astrocytic volume was measured in response to hypoosmotic stress and under isoosmotic conditions. In conditions of hypoosmolarity, CaM antagonists had no effect on swelling, but inhibited the regulatory volume decrease. PKC activation facilitated the swelling induced by hypoosmotic stress. PKC inhibitors induced cell shrinkage and inhibited the initial phase of regulatory volume decrease, whereas PKC down‐regulation caused pronounced swelling and partial inhibition of regulatory volume decrease. In isoosmotic conditions, CaM antagonists and PKC activation did not affect astrocytic volume, but PKC inhibitors caused shrinking and PKC down‐regulation led to swelling of these cells. These studies indicate the importance of Ca 2+ ‐dependent protein kinases in the regulation of astrocytic cell volume.