D. Wong, F. Bymaster
Sep 1, 1976
Citations
2
Influential Citations
74
Citations
Quality indicators
Journal
Biochemical pharmacology
Abstract
Abstract Nisoxetine inhibits the high affinity uptake of norepinephrine by synaptosomes hypothalamus, brain stem and cerebral cortex of rat brain with inhibitor constants, Ki values, of 1, 2 and 6 nM respectively. The drug also inhibits the high affinity uptake of dopamine by hypothalamic synaptosomes with a Ki value of 9 nM. In corpus striatum, however, the Ki values for nisoxetine to inhibit the uptake ofdopamine and norepinephrine are 360 and 220 nM respectively. Thus, nisoxetine has about 200-fold greater affinity for the uptake sites of norepinephrine than for those of dopamine. Nisoxetine administered at 10 mg/kg i.p. to rats reduces the high affinity uptake of catecholamines by synaptosomes of brain regions. A low affinity process for uptake of catecholamines also occurs in synaptosomes of hypothalamus, brain stem and cerebral cortex but is not blocked by 10−8M nisoxetine. The significance of the low affinity uptake processes is discussed.