cGMP accumulation and gene expression of soluble guanylate cyclase in human vascular tissue

Abstract

Gene expression of soluble guanylate cyclase (sGC) and cGMP accumulation in response to sodium nitroprusside (SNP) were studied in cultured human vascular cells and freshly harvested vascular tissue. As revealed by reverse transcriptase-polymerase chain reaction, cultured smooth muscle and endothelial cells, as well as freshly isolated human vascular tissue, express mRNA for the alpha 3 and beta 3 subunits but not for the alpha 2 and beta 3 subunits is evident even in the absence of increased cGMP accumulation in response to SNP. cGMP accumulation in human cells cultured from different vascular beds typically increased two- to five-fold (maximum of 11.4-fold) over baseline following stimulation with 100 microM SNP. Bovine, murine, canine, and avian vascular smooth muscle cells accumulated similar or lower amounts of cGMP than human cells, whereas porcine, rat, and rabbit smooth muscle cells accumulated greater amounts of cGMP. In freshly harvested human vessels, cGMP accumulation in response to SNP was found to increase fifteen-fold over baseline. In contrast to the SNP-induced cGMP accumulation, cGMP levels in response to particulate guanylate cyclase activator atriopeptin II were equal to or greater in cultured human cells than in fresh human vascular tissue. We conclude that human vascular cells (fresh and cultured) express the mRNA for both a large (alpha 3) and a small (beta 3) sGC subunit and that fresh human cells are more sensitive to SNP stimulation.

Cyclic Nucleotide-gated Channels Mediate Membrane Depolarization following Activation of Store-operated Calcium Entry in Endothelial Cells

“…Thapsigargin stimulates the production of nitric oxide in endothelial cells, which has been reported to activate sGC and increase cGMP (9,10,58). Our studies demonstrated that thapsigargin modestly increased cGMP in cultured PAECs, an increase that was perhaps limited because sGC can be down-regulated in culture (59). Indeed, sGC is expressed in endothelial cells in vivo suggesting calcium agonists produce membrane depolarization through elevations in cGMP.…”

Enhanced Nitric Oxide-Mediated Vascular Relaxation in Radial Artery Compared With Internal Mammary Artery or Saphenous Vein

“…To date, there is limited information on the ⅐NO sensitivity of vascular beds with respect to cGMP production. Papapetropoulos and colleagues 28 investigated the response of human and animal vascular tissues to sodium nitroprusside. They found that vascular endothelium and smooth muscle cells obtained from different vascular beds had distinct cGMP responses to sodium nitroprusside.…”

“…They found that vascular endothelium and smooth muscle cells obtained from different vascular beds had distinct cGMP responses to sodium nitroprusside. 28 One explanation offered by those investigators was a difference in guanylyl cyclase gene expression based on the vascular bed. Our study results are consistent with this contention.…”

α1‐Adrenoceptor activation of PKC‐ε causes heterologous desensitization of thromboxane receptors in the aorta of spontaneously hypertensive rats

“…To determine whether or not the effect of pre-exposure was due to the contraction of the preparation to phenylephrine, the following experiments were performed: (i) the pre-exposure did not affect the second contractions evoked by phenylephrine itself with or without co-incubation with an antagonist of α1-adrenoceptors, phenoxybenzamine (5 × 10 −9 M, Figure 5D); and (ii) incubation for 40 min with 2 × 10 −7 M phenylephrine in the presence or absence of 10 −4 M sodium nitroprusside (to maximally stimulate the production of cyclic GMP; Papapetropoulos et al, 1996) and limit the contraction evoked by phenylephrine during the preincubation] significantly limited the contraction evoked by PGE2; after repeated washout, the basal tension of the rings was the same, regardless of the presence or absence of sodium nitroprusside (1.93 ± 0.06 and, 2.06 ± 0.05; P > 0.05). The co-incubation with sodium nitroprusside did not prevent the inhibitory effect of the pre-exposure to phenylephrine on subsequent contractions to PGE2 (data not shown).…”