English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Phospholipase C is the key enzyme responsible for the hydrolysis of membrane phospholipids phosphatidylinositol 4,5-bisphosphate (PIP 2 ) to two intracellular transmitters - diacylglycerol (DAG) and inositol triphosphate (IP 3 ). PLC activation of smooth muscle leads to an increase in the concentration of IP 3 and DAG which initiates the increase in the concentration of calcium ions into the cytoplasm as a result of the flow from the intracellular and then from extracellular pool. Main aim of this study was to evaluate the effect of PLC inhibitor U-73122 on vascular smooth muscle contraction stimulated pharmacologically with phenylephrine (PHE, α 1 -adrenoceptor agonist) and arg-vasopressin (AVP, vasopressin receptor agonist). Material and methods. Experiments were performed on isolated and perfused tail artery of Wistar rats. Contraction force in our model was measured by increased level of perfusion pressure with a constant flow. Results. Reactivity of vascular smooth muscle cells to PHE (10 -9 - 10 -3 M/L), and AVP (10 -10 – 10 -4 M/L), in the control group and in the presence of U-73122 – phospholipase C inhibitor at concentrations 1, 3 and 10 μM/l was analyzed. EC 50 values calculated for PHE and AVP were 7.52 (±0.97) x10 -8 M/L and 1.84 (±0.6) x10 -8 M/L, respectively. The concentration-response curves obtained for PHE and AVP in the presence of U-73122 were shifted to the rightward with a decrease in maximal responses. In the presence of U-73122 the significant and dose dependent reduction in perfusion pressure was found for both agonists for calcium influx from intracellular calcium stores and from extracellular space. Conclusion. Results of our experiments suggest that in the presence of phospholipase C inhibitors, contraction induced by G-protein coupled receptors activation may by effectively inhibited by reduction in calcium influx from intra and extracellular calcium stores.

Effect of phospholipase C inhibition on vascular smooth muscle contraction