CGMP ACCUMULATION AND GENE-EXPRESSION OF SOLUBLE GUANYLATE-CYCLASE INHUMAN VASCULAR TISSUE

Gene expression of soluble guanylate cyclase (sGC) and cGMP accumulati on in response to sodium nitroprusside (SNP) were studied in cultured human vascular cells and freshly harvested vascular tissue. As reveale d by reverse transcriptase-polymerase chain reaction, cultured smooth muscle and endothelial cells, as well as freshly isolated human vascul ar tissue, express mRNA for the alpha(3) and beta(3) subunits but not for the alpha(2) or beta(2) sGC. In cultured human cells, expression o f the alpha(3) and beta(3) subunits is evident even in the absence of increased cGMP accumulation in response to SNP. cGMP accumulation in c ultured human cells from different vascular beds typically increased t wo- to fivefold (maximum of 11.4-fold) over baseline following stimula tion with 100 mu M SNP. Bovine, murine, canine, and avian vascular smo oth muscle cells accumulated similar or lower amounts of cGMP than hum an cells, whereas porcine, rat, and rabbit smooth muscle cells accumul ated greater amounts of cGMP. In freshly harvested human vessels, cGMP accumulation in response to SNP was found to increase fifteenfold ove r baseline. In contrast to the SNP-induced cGMP accumulation, cGMP lev els in response to the particulate guanylate cyclase activator atriope ptin II were equal or greater in cultured human cells than in fresh hu man vascular tissue. We conclude that human vascular cells (fresh and cultured) express the mRNA for both a large (alpha(3)) and a small (be ta(3)) sGC subunit and that fresh human cells are more sensitive to SN P stimulation. (C) 1996 Wiley-Liss, Inc.