| Abstract: | The acute effects of dimethyl sulfoxide (DMSO) on parathyroid hormone (PTH) release and the cytoplasmic Ca2+ concentration (Ca2+i) were studied in dispersed bovine cells and cells isolated from human parathyroid adenomas. At extracellular Ca2+ concentrations in the 0.5-3.0 mM range, but not at less than 25 nM, addition of 2% DMSO caused a rapid rise of Ca2+i. This effect corresponded to an inhibition of PTH release and there was a strong negative correlation between Ca2+i and secretion. The actions of DMSO on Ca2+i and PTH release were less pronounced in the pathological human cells. The data are consistent with a DMSO effect on the Ca2+-sensor function of the parathyroid cell, possibly mediated by an altered plasma membrane fluidity. |
