The 5-HT7 receptor contributes to increased hindquarter blood flow caused by skeletal muscle contraction.

Serotonin (5-hydroxytryptamine, 5-HT) at low plasma concentrations reduces blood pressure and dilates some skeletal muscle arterioles in the rat. We hypothesized that the 5-HT7 receptor is essential for both 5-HT-induced changes in blood pressure and skeletal muscle arteriolar function. Male 5-HT7 receptor knock out (KO) rats under isoflurane anesthesia had a higher resting hindquarter vascular resistance [HQVR; mm Hg/ml/min; KO (16.