[Monoclonal antibodies to insulin influencing its biological activity]. / Monoklonal'nye antitela k insulinu, vliiaiushchie na ego biologicheskie aktivnost'.

Somatic hybridization was employed for obtaining 335 hybridomas producing monoclonal antibodies to insulin. Twelve hybridomas were cloned by a method of maximum dilutions, and specific immunoglobulins, secreted by them, were characterized by solid phase immunoenzyme assay. Monoclonal antibodies possessed different activity with relation to human, porcine and cattle insulins, indicating their specificity to different epitopes on the insulin molecule. Antibodies of IN-2 and IN-3 clones were capable of inhibiting insulin biological activity in vivo. In experiments on rabbits antibodies of IN-2 clone decreased a 3-fold insulin hypoglycemic action, and antibodies of IN-3 clone caused an increase in the life span of mice after administration of insulin at high doses to them.

[3H-cortisol binding with hormone-sensitive and hormone-resistant thymocytes]. / Sviazyvanie 3H-kortizola s gormonchuvstvitel'nymi i gormonrezistentnymi timotsitami.

A study was made of 3H-cortisol binding with total, hormone-sensitive and hormone-resistant populations of adrenalectomized rat thymocytes before and after their division using BCA and percoll gradients. Subpopulations of small and large thymocytes obtained by using percoll were hormone resistant and hormone sensitive, respectively. The method of thymocyte division on percoll gradient was effective for a study of thymocyte interaction with glucocorticoids. The data obtained showed that there were differences in the index of cortisol binding with subpopulations of rat thymocytes.

[Effect of polymer-immobilized cortisol on 3H-uridine incorporation into the thymocyte RNA of rats]. / Vliianie kortizola, immobilizovannogo na polimere, na vkliuchenie 3H-uridina v RNK timotsitov krys.

It was found that cortisol immobilized on polyvinylpyrrolidone (PVP-GC) suppresses the incorporation of 3H-uridine into RNA of thymocytes of intact but not adrenalectomized rats. PVP-GC at the concentration of 10(-6) M enhanced the inhibiting effect of dexamethasone (10(-9) M) and cortisol (10(-9) M) on RNA biosynthesis in thymocytes of adrenalectomized animals.

[Plasma membrane of thymocytes--home of specific glucocorticoid binding sites]. / Plazmaticheskaia membrana timotsitov--mesto lokalizatsii spetsificheskikh uchastkov sviazyvaniia gliukokortikoidov.

The incubation of rat thymocytes with 3H-cortisol in the presence of cortisol immobilized on polyvinylpyrrolidone (PVP-GC) produces a decrease in 3H-cortisol uptake by these cells. PVP-GC is shown to compete with cortisol for specific binding sites on thymocytes, without penetrating into cells. It is therefore, concluded that plasma membranes of thymocytes contain specific glucocorticoid binding sites.