Why the study?
Does phenylephrine increase the force of contraction and inositol trisphosphate levels in trabeculae isolated from nonfailing human hearts?
Does phenylephrine increase the force of contraction and inositol trisphosphate levels in trabeculae isolated from nonfailing human hearts?
The positive inotropic effect of alpha 1-adrenoceptor stimulation in the normal human heart may be causally related to an increase in inositol trisphosphate.
Answers are grounded in this paper and cite their sources.
May link α1-stimulation to inotropy via inositol phosphates in cardiac tissue; leaves open human translation and clinical relevance.
In human-isolated ventricular myocardium the alpha 1-adrenoceptor agonist phenylephrine has a positive inotropic effect but its mechanism is largely unknown. We studied the effects of phenylephrine in trabeculae isolated from three nonfailing human hearts. We found that the force of contraction rose concentration-dependently (1-300 mumol/L), maximally, to about 235% of control (at 100 mumol/L). The inositol phosphates were increased to 195-262%, whereas the phosphatidylinositol phosphate and phosphatidylinositol bisphosphate decreased to 69-73% of control. The present results suggest that the alpha 1-adrenoceptor-mediated increase in inositol trisphosphate and the positive inotropic effect may be causally related in the normal human heart.
No takes yet. Share an insight, caveat, or question.
Kohl et al. (1989) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: