[COMPARATIVE CHARACTERIZATION OF HYALURONIDASE ISOFORMS OF THE 1ST TYPE IN SOMATIC TISSUES AND SERUM OF WHITE RATS].

There are identified 3 proteins with molecular mass of 63, 73 and 132 kDa, exhibiting the properties of the hyaluronidase of the 1st type in the liver, spleen, renal papilla, skin and serum by the method of zymography. A protein with a molecular mass of 73 kDa was detected in all studied tissues and serum, while protein with a molecular mass of 63 kDa was present only in the tissues, and the protein with molecular mass of 132 kDa was present only in the serum. It is discussed the possibility of aggregation of 63 kDa protein molecules in the dimers with the formation of a 132 kDa protein in the serum.

Selective V₂-Agonist of Vasopressin Desmopressin Stimulates Activity of Serum Hyaluronidase.

Effects of desmopressin (arginine vasopressin V2 receptor agonist) were studied for elucidation of the possible role of the kidneys in the regulation of blood hyaluronidase activity. Similar to vasopressin, intraperitoneal administration of desmopressin to Wistar rats increased blood hyaluronidase activity by 30%. Against the background of water load, nether desmopressin nor vasopressin increased blood hyaluronidase activity.

[Hyaluronidase activity of Wistar rat blood plasma: effect of dehydration and vasopressin].

Effect of dehydration and arginine vasopressin treatment (Arg-VP Sigma, USA, 50 ng/100 g b.wt. ip.

[Protein phosphorylation in the vasopressin-sensitive sections of rat nephrons].

Specific vasopressin-sensitive phosphorylation of the collecting duct proteins with molecular mass 15, 20, 25, and 33 kDa, was revealed. The proteins implemented the hormonal effect of vasopressin by means of qualitative molecular modifications with subsequent phosphorylation.

[Phosphorylation of proteins in collecting tube cells under the effect of vasopressin].

Endogenous phosphorylation of proteins in cell suspensions of collecting tubes was studied. Using SDS disc electrophoresis in polyacrylamide gel with subsequent autoradiography, it was shown that vasopressin increases the 32P incorporation into two proteins with molecular masses of 15 kDa and 33 kDa, which serve as endogenous substrates for cAMP-dependent protein kinase. The hormone-dependent phosphorylation of these proteins was typical of the membrane fraction of collecting tube cells but was absent in the cytosolic fraction.

[Phosphorylation of proteins in the kidney papillary zone by endogenous cAMP-dependent protein kinases].

Using SDS-PAAG electrophoresis with subsequent autoradiography, several proteins from plasma membranes and cell cytosol of rat kidney papillary zone were identified as substrates for endogenous cAMP-dependent protein kinases. The cAMP-dependent phosphorylation of plasma membrane proteins was made possible only after the destruction of membrane vesicles. Plasma membrane and cytosol fractions were found to contain a 58 kDa protein whose properties are similar to those of the regulatory subunit of cAMP-dependent protein kinase of the second type.

[Changes in the receptor link during the development of renal sensitivity to aldosterone and antidiuretic hormone].

The aldosterone, cAMP and ADH receptors were studied in kidneys of 10-14- and 60-day old rats. Concentrations of aldosterone and cAMP receptors were reduced, while ADH binding was increased during the period of maturation of kidney functions. The investigation of the affinity and molecular weights of cAMP and ADH receptors suggests their complex nature and altering of their individual properties during ontogenesis.