Aging does not alter the voltage-dependent release of endogenous dopamine from mouse striatal synaptosomes.
Striatal synaptosomes isolated from 3-, 12-, and 24-month-old C57B1/6J mice were exposed to low (5 mM) and high (30 mM) concentrations of potassium of 1, 3, 5, 15 and 30 s. There were no age-related differences in the total intrasynaptosomal content of dopamine among the three age groups of mice. The basal release of endogenous dopamine from synaptosomes isolated from 24-month-old animals was significantly greater than that from synaptosomes isolated from 3-month-old animals at all time points tested. Similarly the potassium stimulated release of dopamine from 24-month-old animals was also higher than that from the 3-month-old group, but this increase was not statistically significant. The net voltage-dependent release of dopamine (stimulated minus basal) was similar for all groups at all time points measured. The increase in basal dopamine release in the 24-month-old animals may reflect an increased fragility or leakiness of the synaptosomal preparation.
Woodward
J J
JJ
Division of Pharmacology and Toxicology, College of Pharmacy, University of Texas, Austin, TX 78712.
Leslie
S W
SW
Severson
J A
JA
Wilcox
R E
RE
D000375:Aging / Q000378:metabolism*; D000818:Animals; D003342:Corpus Striatum / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology; D004298:Dopamine / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D011188:Potassium / Q000494:pharmacology; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology
D011188:Potassium; D004298:Dopamine