The aims of the present study are to investigate the effect of vasoconstriction and to explore the mechanism of rutae- carpine. The research findings showed that rutaecarpine could induce contractions of the rat thoracic aorta in vitro. The inhibitors of Rho-kinase and inositol 1,4,5-triphosphate receptor （IP 3 R） could suppress the effect of rutaecarpine-induced vasoconstriction. In the study of A7r5 cells （a line of smooth muscle cells）, 300 μg/L rutaecarpine promoted the concentration of intracellular Ca 2＋ and enhanced the IP 3 R expression, which connects with 1,4,5-triphosphate to evoke the release of Ca 2＋ from the intracellular stores. Rutaecarpine increased the RhoA mRNA expression when the cells were pretreated with inhibitor H-1152, and improved the levels of phosphorylation of myosin light chain phosphatase （MLCP） and myosin light chain （MLC）. These results suggest that rutaecarpine plays a role in vasoconstriction relative to the RhoA/MLCP-MLC signaling pathway, which denotes a new field of rutaecarpine in pharmacology.
A series of animal models are used to investigate the anti-depression mechanism of flavonoids in scutellariae radix （SR） in vivo. Depression-like behavior in mice was studied after intraperitoneal administra- tion of SR. The results showed that SR administered to mice by the intraperitoneal route obviously short- ened the duration in the tail suspension test and the forced swimming test, aggravated the symptoms of eyelid ptosis, akinesia, and mortality caused by reserpine, prolonged climbing times, affected the condi- tioned place preference, and increased sugar consumption in mice. However the SR did not affect the head twitches induced by 5-HTP, locomotor activity in mice, the toxicity of yohimbine, and the body temperature decrease caused by high dosage of apomorphine. The tests show that SR has some anti-depression effect related to the dopamine system. Furthermore another anti-depression mechanism was possible that could affect the mechanism of brain reward, bring positive reinforcement, and increase the sensitivity to euphoria in mice.
