INFLUENCE OF RYANODINE AND INOSITOL TRISPHOSPHATE RECEPTORS INHIBITIONS ON Ņa2+ EXIT FROM INTRACELLULAR
STORES OF PORCINE OOCYTES STIMULATED BY PROLACTIN AND GTP
V. Yu. Denisenko, T. I. Kuzmina 1
All-Russian Research Institute of Farm Animal Genetics and Breeding, St. Petersburg-Pushkin;
1 e-mail: tkuzmina@rol.ru
The influence of ryanodine and inositol triphosphate receptors inhibitors on Ņa2+ exit from
intracellular stores of porcine oocytes stimulated by prolactin and GTP was investigated using fluorescent dye
chlortetracycline. Porcine oocytes were isolated from ovaries with yellow body. Ņa2+ exit from
intracellular stores of porcine oocytes activated by prolactin (5 and 50 ng/ml) in calcium free medium was decreased
after treatment of oocytes by heparin (inhibitor of inositol triphosphate receptors) and was not changed after
treatment of oocytes by ruthenium red (inhibitor of ryanodine receptors). Inhibition of protein kinase C did not
affect on the Ņa2+ exit stimulated by prolactin. GTP did not stimulate Ņa2+ exit from
intracellular stores of pig oocytes, and inhibitors of both calcium channels and proteinkinase C had no influence on
this process. The joint action of prolactin and GTP did not result in additional Ņa2+ exit from
intracellular stores of oocytes after both pretreatment and untreatment by the inhibitor of protein kinase C. The data
obtained testify to activation of IP3-sensitive receptors under effect of prolactin and in the absence of GTP
influence on these receptors.
Key words: prolactin, GTP, calcium, pig oocytes
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