TY - JOUR
AU - Lohr, James W.
AB - Abstract We examined the effects of dissolved nitric oxide (NO) gas on cytoplasmic calcium levels (Ca 2+ i ) in C6 glioma cells under anoxic conditions. The maximum elevation (27 ± 3 nM) of Ca 2+ i was reached at 10 μM NO. A second application of NO was ineffective if the first was >0.5 μM. The NO donor diethylamine/NO mimicked the effects of NO. Acute exposure of the cells to low calcium levels was without effect on the NO-evoked response. Thapsigargin (TG) increased Ca 2+ i and was less effective if cells were pretreated with NO. Hemoglobin inhibited the effects of NO at a molar ratio of 10:1. 8-Bromo-cGMP was without effect on the NO-evoked response. If cells were pretreated with TG or exposed chronically to nominal amounts of calcium, NO decreased Ca 2+ i . The results suggest that C6 glioma cells have two receptors for NO. One receptor (NO A ) elevates Ca 2+ i and resides on the endoplasmic reticulum (ER). The other receptor (NO B ) decreases Ca 2+ i and resides on the plasmalemma or the ER. The latter receptor dominates when the level of calcium within intracellular stores is diminished. neuroglia glioma astrocytes Footnotes Address for reprint requests and other correspondence: C. L. Bowman, Buffalo Institute for Medical Research, Veterans Affairs Medical Center, 3495 Bailey Ave., Buffalo, NY 14215-1129 (E-mail: bowman@acsu.buffalo.edu ). The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “ advertisement ” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact. Copyright © 2001 the American Physiological Society
TI - Regulation of cytoplasmic calcium levels by two nitric oxide receptors
JF - AJP - Cell Physiology
DA - 2001-09-01
UR - https://www.deepdyve.com/lp/the-american-physiological-society/regulation-of-cytoplasmic-calcium-levels-by-two-nitric-oxide-receptors-o2UlfCavET
VL - 281
IS - 3
DP - DeepDyve
ER -