[Alterations in the cyclase system of skeletal muscles and in the content of cyclic nucleotides in blood plasma of rats after the administration of caffeine].

Concentration of cyclic nucleotide monophosphates was increased both in rat skeletal muscles and in blood plasma after enteral administration of caffeine. A decrease in content of cAMP and cGMP down to the initial level coincided with the activation of phosphodiesterase in skeletal muscles. A direct correlation was found between the alteration in cyclic nucleotides content in skeletal muscles and in blood plasma.

[Effect of exogenous calmodulin on lymphocyte proliferation in healthy individuals].

The action of calmodulin (CM) given in doses of 10(-5)-10(-8) M on lymphocyte proliferation in healthy subjects was studied. All the test doses of CM produced a stimulant effect 72 h after the lymphocyte incubation was commenced. The rate of 3H-thymidine incorporation experimentally was 1.

[Method of measuring binding constants and the number of specific cyclic AMP receptor sites in tissue extracts].

A method for evaluation of binding constants and of amount of cAMP binding sites in crude tissue extracts was developed. The method is based on equilibrium binding of 3H-cAMP by proteins with subsequent ultrafiltration. Hydrolysis of cAMP and its unspecific sorption by proteins were eliminated under the conditions selected.