Publications [#134125] of Mark W. Dewhirst

Papers Published

1. RA Lindberg, MW Dewhirst, BJ Buckley, CS Hughes, AR Whorton, Ca(2+)-dependent nitric oxide release in endothelial but not R3230Ac rat mammary adenocarcinoma cells., The American journal of physiology, UNITED STATES, vol. 271 no. 1 Pt 1 (July, 1996), pp. C332-7, ISSN 0002-9513
   (last updated on 2004/03/30)

   Abstract:
   We have characterized the ability of several cell types associated with the microvasculature of solid tumors to release nitric oxide (NO.) in response to increases in cytosolic Ca2+ concentration ([Ca2+]c). EA.hy926 immortalized human umbilical vein endothelial cells (EC), rat fibroblasts (RFL), and tumorigenic cells isolated from R3230Ac rat mammary adenocarcinoma (MaC) were treated with thapsigargin (TG), an inhibitor of Ca(2+)-ATPase. NO. output was measured via a chemiluminescence detection system. Baseline NO. output was detectable only for EC. TG caused a significant increase in EC NO. output that could be blocked with NG-monomethyl-L-arginine and restored with L-arginine. TG did not stimulate NO. release from RFL or MaC cells, despite elevating [Ca2+]c in all cells. A Ca(2+)-dependent isoform of NO synthase (eNOS) was detected by immunoblot only in EC. These data indicate that EC, but not RFL or MaC, are capable of Ca(2+)-dependent NO. release and suggest that any Ca(2+)-dependent NO. release within this tumor is primarily of endothelial (and not tumorigenic cell) origin.

   Keywords:
   Adenocarcinoma • Animals • Arginine • Calcium • Calcium-Transporting ATPases • Cell Line • Endothelium, Vascular • Female • Fibroblasts • Humans • Immunoblotting • Isoenzymes • Mammary Neoplasms, Experimental • Nitric Oxide • Nitric Oxide Synthase • Rats • Thapsigargin • antagonists & inhibitors • metabolism • metabolism* • omega-N-Methylarginine • pathology • pharmacology • physiology*