Does 5-hydroxytryptamine have an endothelium-derived hyperpolarizing factor-like effect on coronary flow in isolated rat hearts?
In the present study, we found that 5-HT-induced coronary flow increases are mediated by the activation of 5-HT7 receptor in rat hearts in the absence of L-NAME. Metabolites of cytochrome P450s, small-conductance Ca(2+)-activated K(+) channel, and intermediate-conductance Ca(2+)-activated K(+) channel are involved in 5-HT-induced coronary flow increases in L-NAME-treated hearts, which resemble the mechanisms of EDHF-induced vasorelaxation. The role of large-conductance Ca(2+)-activated K(+) channel in 5-HT-induced coronary flow increases in L-NAME-treated hearts needs further investigation.
In nonpregnant normotensive, formerly preeclamptic women, an elevated uterine artery PI predisposes to subsequent restriction in fetal growth.