HIV-1 coat protein gp120-induced increases in levels of intrasynaptosomal calcium.
The effects of human immunodeficiency virus type-1 (HIV-1) coat protein gp120 on levels of intrasynaptosomal calcium ([Ca2+]i) were determined in rat cortical synaptosomes. gp120 at concentrations of > or = 400 pM, significantly (P < 0.05) increased levels of [Ca2+]i. Treatment with 20 mM KCl, reduced the concentrations of gp120 necessary to produce significant (P < 0.001) increases in [Ca2+]i. gp120-evoked increases in [Ca2+]i were prevented either by treatment with dantrolene or by removal of extracellular calcium with BAPTA. The peak levels of gp120-induced increases in [Ca2+]i were not affected by calcium channel blockers lanthanum and nicardipine, by glutamate receptor antagonists MK-801 and NBQX, or by removal of endogenous glutamate with glutamate dehydrogenase. gp120-induced [Ca2+]i increases in presynaptic terminals may play a role in HIV-mediated effects in the central nervous system.
Nath
A
A
Department of Medical Microbiology, University of Manitoba Faculty of Medicine, Winnipeg, Canada.
Padua
R A
RA
Geiger
J D
JD
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D003620:Dantrolene / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D016257:Fura-2; D015699:HIV Envelope Protein gp120 / Q000494:pharmacology*; D015497:HIV-1 / Q000378:metabolism; D008297:Male; D017680:Potassium Compounds / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013574:Synaptosomes / Q000378:metabolism*; D013997:Time Factors
D015699:HIV Envelope Protein gp120; D017680:Potassium Compounds; D003620:Dantrolene; D002118:Calcium; D016257:Fura-2