[ATP-dependent Ca2+-transporting system in the rat brain during an early period of acute radiation injury].
The rate of Mg2+, Ca2+-ATPase reaction and ATP-dependent Ca2+ accumulation in a preparation of plasma membranes from brain synaptosomes increases 60 min following whole-body X-irradiation of rats with a dose of 0.21 C/kg, a calcium sensitivity of both processes being increased. A unidirectional change in their kinetics indicates the early radiosensitivity of Ca2+ transfer systems in the brain synaptosome membranes. There is an increase in the availability of SH-groups of membrane preparation proteins for SH-reagents and in the sensitivity of Mg2+, Ca2+-ATPase reaction and ATP-dependent Ca2+ accumulation to trifluoperazine, a calmodulin inhibitor. Both processes lose their ability to be activated by exogenous calmodulin. It is suggested that at an early stage of radiation affection, a change occurs in the molecular organization of the ATPase-calmodulin membrane complex in plasma membranes of rat brain synaptosomes.
D000208:Acute Disease; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport / Q000528:radiation effects; D001921:Brain / Q000201:enzymology / Q000378:metabolism* / Q000528:radiation effects; D017301:Ca(2+) Mg(2+)-ATPase / Q000037:antagonists & inhibitors / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000037:antagonists & inhibitors / Q000378:metabolism; D005260:Female; D007700:Kinetics; D008297:Male; D011833:Radiation Injuries, Experimental / Q000201:enzymology / Q000378:metabolism*; D051381:Rats; D013438:Sulfhydryl Compounds / Q000378:metabolism; D013570:Synaptic Membranes / Q000201:enzymology / Q000378:metabolism / Q000528:radiation effects; D013997:Time Factors
D013438:Sulfhydryl Compounds; D000255:Adenosine Triphosphate; D017301:Ca(2+) Mg(2+)-ATPase; D000252:Calcium-Transporting ATPases; D002118:Calcium
ATF-zavisimaia Ca2+transportiruiushchaia sistema mozga krys na rannem étape ostrogo luchevogo vozdeĭstviia.