Traditional Chinese Medicine Tongxinluo Protects Microvascular From Arteriole Spasm Induced by Norepinephrine in Rats Mesentery

Background: Arteriole spasm (AS) served as a common pathogenesis of many diseases. Tongxinluo (TXL), a traditional Chinese formula, has been proved to benefit patients with diseases associated with AS. However, the effect of TXL on AS has not been elucidated, especially on the hemorheology of microcirculation. The aim of this study was to assess the protective function of TXL against AS on microcirculation in rats’ mesentery. Materials and Methods: Arteriole spasm model was established by local administration of norepinephrine in rats’ mesentery. Rats were randomized divided into five groups: sham group (local administration of normal saline), arteriole spasm group, TXL0.4+AS group, TXL0.8+AS group, TXL1.6+AS group. Drugs were administered orally daily for 7 days before modeling. Microcirculation was observed using an upright microscope and recorded to study the hemorheology changes, including spasm time, diameter changes, and arteriole blood flow. Mast cell degranulation was identified by vital staining with topical application of 0.1% toluidine blue. The serum samples were collected for detect of NO and ET-1. Results: Pre-administration of TXL markedly decreased arteriole spasm time, and indicated a dose-dependent effect. Pre-administration of TXL also indicates dose-dependent effect to maintain arteriole diameter in the presence of AS. Pretreatment with TXL significantly inhibited mast cell degranulation induced by AS, TXL also exert great beneficial protection on arteriole blood flow against AS. The serum level of NO and ET-1 had no obvious changes among each groups. Conclusion: AS caused microvascular dysfunction in rats’ mesentery. TXL had a beneficial effect against AS in the perspective of protecting microvascular function, indicated that TXL fight against AS through regulation on microcirculation.