[Catalytic properties of monoamine oxidases during adaptation to altitude chamber hypoxia].
The effect of different exposures to altitude chamber hypoxia (1, 5 or 21 days) upon the catalytic properties of monoaminoxidases (MAO) of fragments of mitochondrial membranes of the Wistar rat liver, which are key enzymes in the metabolism of biogenic amines, was investigated. The MAO activity of A and B types decreased on day 5 and increased on day 21 of exposure. In addition, hypoxia modified catalytic properties of MAO which allowed the enzyme to produce oxidative deamination of nitrogen compounds that do not serve as its substrates under normal conditions. By measuring kinetic constants KM and Vmax, it was found that the enzyme affinity for serotonin increased and the rate of enzymic reaction decreased during hypoxia. The above changes of MAO catalytic properties seem to be associated with qualitative adaptation to hypoxia which triggers new metabolic pathways.
Shatemirova
K K
KK
Zelenshchikova
V A
VA
Min'ko
Iu V
IuV
D000532:Altitude Sickness / Q000378:metabolism*; D000818:Animals; D001273:Atmosphere Exposure Chambers; D001679:Biogenic Amines / Q000378:metabolism*; D002384:Catalysis; D004195:Disease Models, Animal; D000860:Hypoxia / Q000378:metabolism*; D008297:Male; D008930:Mitochondria, Liver / Q000378:metabolism*; D008995:Monoamine Oxidase / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D001679:Biogenic Amines; D005680:gamma-Aminobutyric Acid; D008995:Monoamine Oxidase
Kataliticheskie svoĭstva monoaminoksidaz pri adaptatsii k barokamernoĭ gipoksii.