Melenevska N. The action of cell-bound protein A of staphylococcus and transfer factor of immune reactivity to bacterial antigens upon excitation-relaxation in the intestinal smooth muscles

The object: regulation mechanisms of excitation and inhibition in gastro-intestinal smooth muscles. The aim: investigation of action mechanisms of Staphylococcus aureus cell-bound protein A and transfer factor of immune reactivity to this antigen, diphtheria-clostridium anatoxin on spontaneous contractile activity and electric activity, and also induced with excitation and inhibition neuromediators in taenia coli smooth muscles. The methods: sucrose-gap technique; tension measure; actomyosin isolation from smooth muscles; estimation of its ATP-activity; isolation of smooth muscle cells and fluorescence technique of estimation of cytosolic free-calcium concentration in smooth muscle cells. The results: cell-bound protein A depolarizes smooth muscle cells membrane in dose-dependent manner, enhances, in time - inhibits the inhibiting action of P2Y- and P2X-receptor agonists - ATP, and also P2Y - UTP in smooth muscles, abolishes hyperpolarization induced by sodium nitroprusside. Depolarization evoked with ATP on a background of nitric oxide-induced hyperplarization is not sensitive to this substance. N-nitro-L-arginine inhibits substance excitation action on relaxation, evoked with nicotine. This protein abolishes inhibiting action of ATP (or sodium nitroprusside) in histamine-induced contraction of smooth muscles, enhances caffeine-and carbacholine-evoked changes of calcium concentration in isolated smooth muscle cells. Cell-bound protein A (10-6, 10-5mg/ml) increases ATP-ase activity of stomach smooth muscle actomyosin. Transfer factor of immune reactivity to diphtheria-clostridium anatoxin modulates depolarization slow waves, enhances ATP and UTP rebound effect of membrane depolarization, transforms hyperpolarization into depolarization. Transfer factor of immune reactivity to cell-bound protein A modulates the level of membrane potential, hyper-potassium depolarization and phase-component of contraction, inhibits the purinergic inhibition. It is introduced in education work of Taras Shevchenko Kyiv national university. The field of use: biophysics, physiology, immunology.