Effect of hyperoxia on histamine metabolism in rat brain synaptosomes: preliminary observations.
Adult male Wistar rats were submitted to normobaric hyperoxygenation for 1 and 4 hours, then brain synaptosomes were isolated and uptake and release of the histamine precursor - histidine (His), histamine (HA) level and His metabolizing enzymes activities were measured. This uptake in hyperoxic synaptosomes was inhibited by about 20%. After 1-hour hyperoxia, a tendency towards an increase of the HA level, but a significant increase histidine decarboxylase (HD) and histamine methyltransferase (HMT) activities were observed. Four-hour hyperoxia caused a decrease of both the HA level and the activities of both enzymes, especially HMT. The changes were reversed in 1-hour posthyperoxic recovery, except for histidine uptake which remained inhibited.
Waśkiewicz
J
J
Department of Neurochemistry, Medical Research Centre, Polish Academy of Sciences, Warsaw.
Wałajtys-Rode
E
E
Rafałowska
U
U
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D006632:Histamine / Q000378:metabolism*; D006633:Histamine Antagonists; D006637:Histamine N-Methyltransferase / Q000037:antagonists & inhibitors / Q000378:metabolism; D006639:Histidine / Q000378:metabolism; D006640:Histidine Decarboxylase / Q000037:antagonists & inhibitors / Q000378:metabolism; D008297:Male; D010100:Oxygen / Q000008:administration & dosage* / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism*; D013997:Time Factors
D006633:Histamine Antagonists; D006639:Histidine; D006632:Histamine; D006637:Histamine N-Methyltransferase; D006640:Histidine Decarboxylase; D010100:Oxygen