Avtor/Urednik		Horvat-Žnidaršič, Irena
Naslov		Vpliv krotoksina na živčno-mišični prenos
Tip		monografija
Kraj izdaje		Ljubljana
Založnik		Medicinska fakulteta
Leto izdaje		1997
Obseg		str. 67
Jezik		slo
Abstrakt		The aim of our study was to determine the effect of neurotoxic crotoxin (CTx), isolated from the poison of the South American rattlesnake Crotalus durissus terrificus on the neuromuscular transmission. The toxin blocks predominately transmitter secretion from the nerve endings of motoneurons, but in other experiments it seems to act on the postsynaptic site, where it blocks nicotinic receptors. Another problem with understanding the mechanisms of phospholipase A2 neurotoxin's farmacological action is their enzymatic activity. Phospholipase Az activity was shown to be necessary, but not suffcient for the toxic action of CTx. Phospholipase Az neurotoxin cleaves phospholipids in the synaptic membranes and cleaves away fatty acids. The action of the side products of the hydrolitic action of the toxin, especially arachidonic acid, was tested. It was concluded that blockers of the arachidonic acid metabolism are not able to block the action of CTx. Recently, the importance of different parts of CTx molecule for the toxic and phospholipase action was studied with biochemical and immunological experiments and correlations of both was tested. Our first hypothesis was that CTx in addition to blocking ACh release from motoneurons it blocks nicotinic receptors on the postsynaptic membrane in relatively high concentrations. With the use of monoclonal antibodies we should selectivelly block catalytic phospholipase Az and toxic site on the CTx molecule. Our second hypothesis was that the blockade of catalytic site alone is enough for the blockade of pharmacological action of CTx. According to our prediction that phospholipase A2 activity is essential for CTx action, our third hypothesis was that the side products of the hydrolytic action of CTx on the membrane phospholipids, especially arachidonic acid are important mediators of CTx action. (Abstract truncatet at 2000 character.)
Deskriptorji		ISOMETRIC CONTRACTION NEUROMUSCULAR JUNCTION CROTOXIN SYNAPTIC TRANSMISSION MOTOR ENDPLATE RANIDAE MICE CROTALUS PHOSPHOLIPASES A ACETYLCHOLINE CARBACHOL ANTIBODIES, MONOCLONAL ASPIRIN DEXAMETHASONE MICROSCOPY, ELECTRON, SCANNING TRANSMISSION ELECTROCARDIOGRAPHY RESPIRATION