Postmortem stability of dopamine-sensitive adenylate cyclase, guanylate cyclase, ATPase, and GTPase in rat striatum.
The stability of dopamine-sensitive adenylate cyclase, guanylate cyclase, ATPase, and GTPase was measured in homogenates of rat striatal tissue frozen from 0 to 24 h postmortem. ATPase, GTPase, and Mg2+-dependent guanylate cyclase activities showed no significant change over this period. Mn2+-dependent guanylate cyclase activity was stable for 10 h postmortem. Basal and dopamine-stimulated adenylate cyclase activity decreased markedly during the first 5 h. However, when measured in washed membrane preparations, these adenylate cyclase activities remained stable for at least 10 h. Therefore, the postmortem loss of a soluble activator, such as GTP, may decrease the adenylate cyclase activity in homogenates. These results are not consistent with an earlier suggestion that there is a postmortem degradation of the enzyme itself. Other kinetic parameters of dopamine-sensitive adenylate cyclase can also be measured independently of postmortem changes. Thus, it is possible to investigate kinetic parameters of dopamine-sensitive adenylate cyclase, guanylate cyclase, ATPase, and GTPase in human brain obtained postmortem.
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000266:Adenylyl Imidodiphosphate / Q000494:pharmacology; D000818:Animals; D003342:Corpus Striatum / Q000201:enzymology* / Q000473:pathology; D004298:Dopamine / Q000494:pharmacology*; D020558:GTP Phosphohydrolases / Q000378:metabolism*; D006162:Guanylate Cyclase / Q000378:metabolism*; D006165:Guanylyl Imidodiphosphate / Q000494:pharmacology; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*; D011180:Postmortem Changes; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
D000266:Adenylyl Imidodiphosphate; D006165:Guanylyl Imidodiphosphate; D010744:Phosphoric Monoester Hydrolases; D000251:Adenosine Triphosphatases; D020558:GTP Phosphohydrolases; D000262:Adenylyl Cyclases; D006162:Guanylate Cyclase; D008274:Magnesium; D004298:Dopamine