SUMMARY This study is directed to solve one of the major problems of reproductive biology – male infertility, videlicet to explore mechanisms determining sperm capacitation induction as consequence of the impact of different agents: identification of the role of microfilaments and protein kinase A and estimation of capability of glucose to inhibit the capacitation stimulated by joint action of theophylline and GDP. <...> The joint effects of theophylline and GDF stimulates capacitation in spermatozoa after pretreatment with chlortetracycline (CHTC). <...> It is shown that microfilaments are involved in the implementation of the action of theophylline and GDF, as evidenced by the decrease in the number of capacitated spermatozoa after the treatment of sperm with inhibitor of polymerization of microfilaments (cytochalasin D). <...> The same effect was observed in the pretreatment of sperm by inhibitor of protein kinase A (PKA) (compound H-89), from which we can draw a conclusion about the participation PKA in the mechanism of bull sperm capacitation, stimulated by the combined action of theophylline and GDF. <...> It was also found that the stimulatory effect of theophylline and GDF on sperm capacitation was inhibited by glucose (we have not found stimulating effect of these compounds on the sperm capacitation after pretreatment spermatozoa by glucose). <...> Эффект гуаниновых нуклеотидов и протеинкиназы С на стимулированное пролактином освобождение Са2+ из внутриклеточных депо ооцитов свиней. <...> Relationship between calcium, cyclic AMP, ATP, and intracellular pH and the capacity of hamster spermatozoa to express hyperactivated motility. <...> Ca2+regulating mechanisms that modulate bull sperm capacitation and acrosomal exocytosis as determined by chlortetracycline analysis <...>