BACKGROUND: To explore the protective effects of Shexiang Tongxin Dropping Pill (STP) in improving peripheral microvascular dysfunction in mice and to explore the involved mechanism.

MATERIAL AND METHODS: A peripheral microvascular dysfunction model was established by combined myocardial infarction (MI) and lipopolysaccharide (LPS) injection in mice. Then, the mice were randomized into a model group (n=10) or an STP group (n=10), which were treated with normal saline and STP, respectively. The cremaster muscle microvascular blood flow velocity and numbers of leukocytes adherent to the venular wall were evaluated before and after drug intervention. We assessed the expression of adhesion molecule CD11b and related transcript factor FOXO1 in leukocytes, cystathionine-γ-lyase (CSE) mRNA expression in the cremaster muscle, and mitochondrial DNA copy numbers.

RESULTS: Compared with those of control mice, the cremaster microvascular blood flow velocity, cremaster CSE expression, and mitochondrial DNA copy number in mice from the model group were significantly lower and leukocyte adhesion and CD11b and FOXO1 expression were significantly higher. Intervention with STP could significantly increase the cremaster microvascular flow velocity (0.480±0.010 mm/s vs. 0.075±0.005 mm/s), mRNA expression of cremaster CSE, and mitochondrial DNA copy number, but it inhibited leukocyte adhesion and decreased leukocyte CD11b and FOXO1 expression.

CONCLUSIONS: STP significantly improved peripheral microcirculation, in which increased CSE expression might be the underlying mechanism.

Keywords: Microvessels, Blood Flow Velocity, CD11b Antigen, Cell Adhesion, Cystathionine gamma-Lyase, Drugs, Chinese Herbal, Forkhead Box Protein O1, Hydrogen Sulfide, Leukocytes, Lipopolysaccharides, Microcirculation, Muscles, Random Allocation, Regional Blood Flow