Modulation of Ca2+ Channels by Opioid Receptor Antagonists in Mesenteric Arterial Smooth Muscle Cells of Rats in Hemorrhagic Shock

Abstract

The effects of hemorrhagic shock on Ba currents ( ) via Ca channels and the regulation of the channels in the vascular hyporesponse stage of hemorrhagic shock by opioid receptor antagonists were examined by using the whole-cell recording of patch-clamp technique in mesenteric arterial smooth muscle cells of rats. The results showed that hemorrhagic shock induced an inhibition of Ca channels in the cells; 10 micro M of naloxone and 100 n of naltrindole, nor-binaltorphimine, and beta-funaltrexamine increased the in the cells of rats in shock. After inhibition of protein kinase C by using 1-(5-isoquindinesulfonyl)-2-methylpiperazine via electrodes, the enhancement of by the antagonists was not observed. These results suggested that the inhibition of Ca channel induced by hemorrhagic shock was mediated by delta-, kappa-, and mu -opioid receptors in the cells and may be partly responsible for vascular hyporesponse. The enhancement of was mediated by activation of protein kinase C and may be responsible for the antagonist-caused improvement in the response of resistance arteries to vasoactive stimulants at the decompensatory stage of hemorrhagic shock.

Immobilization Stress Inhibits Intimal Fibromuscular Proliferation in the Process of Arterial Remodeling in Rats

“…Therefore, the results of the present study suggest that SMCs have functional μ-opioid receptors whose signal transduction pathway interferes with both proliferation and migration. Although SMCs have been reported to possess μ-opioid receptors, their function was to modify SMC contraction through an increase in the intracellular Ca 2+ concentration (23,24). In other cell types, END modifies the cell biology through μ-opioid receptors.…”

Effects of Nociceptin and Nocistatin on Uterine Contraction

“…NST does not bind to any of the classical opioid receptors, or to the NOP-R receptor (Fantin, Fischetti, Trapella, & Morari, 2007;Johnson & Connor, 2007), and this inhibition is therefore not likely to be mediated by opioid receptors. On the other hand, NX induces an increase in inward Ca 2+ currents (Kai, Wang, Hu, Shi, & Liu, 2002). These findings raise the possibility that the inhibitory effect of NX on NST-induced uterus relaxation may be mediated by the opening of inward rectifying Ca 2+ channels.…”

Preliminary study on the mechanism of oridonin-induced apoptosis in human squamous cell oesophageal carcinoma cell line EC9706

“…The same parameters were used for all scans. Following the technique described previously, 6 six to eight views in all experimental groups were selected, each view including five cells. The cells were subjected to fluorescence intensity analysis and curves showing the change in fluorescence intensity of the Ca 2þ indicator over time were generated.…”