Increased low affinity dopamine uptake in rat striatum after hypobaric hypoxia.
The influence of a hypobaric hypoxia on the dopamine uptake was studied in rat striatum using a concentration range of dopamine from 30 nM to 0.1 mM. Uptake kinetics were calculated by a non-linear regression computer procedure assuming one carrier protein with two binding sites and negative cooperativity. Hypoxia most prominently affected the low affinity uptake site2; a marked increase of Vmax2 was always obtained. This effect seems to be related to the degree of hypoxia and persists for 10 hours at least. For the high affinity uptake site1, a transient decrease of the Vmax1 was apparent but this effect was less reproducible than the alterations of the low affinity uptake site2. These findings are discussed in the context of increased neuronal dopamine release after oxygen deprivation both in vivo and in vitro.
Berndt
C
C
Institute of Pathological and Clinical Biochemistry, Faculty of Medicine Charite, Humboldt University, Berlin, G.D.R.
Dubiel
W
W
Scheuch
C
C
Gross
J
J
D000818:Animals; D001692:Biological Transport; D003342:Corpus Striatum / Q000378:metabolism*; D004298:Dopamine / Q000378:metabolism*; D000860:Hypoxia / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D008962:Models, Theoretical; D051381:Rats; D011919:Rats, Inbred Strains; D011954:Receptors, Dopamine / Q000378:metabolism
D011954:Receptors, Dopamine; D004298:Dopamine