Effect of the icariin on endothelial microparticles, endothelial progenitor cells, platelets, and erectile function in spontaneously hypertensive rats

Objectives To investigate the effect of icariin on endothelial microparticles, endothelial progenitor cells, platelets, and erectile function in spontaneously hypertensive rats. Materials and methods Twelve 8-week-old healthy male Wistar-Kyoto rats and 12 spontaneously hypertensive rats were randomly divided into four following groups: Wistar-Kyoto control group (normal saline 1 ml/d given by gavage), Wistar-Kyoto + icariin group (icariin 10 mg/kg x d dissolved in 1 ml normal saline and given by gavage), spontaneously hypertensive rats control group (normal saline 1 ml/d given by gavage), and spontaneously hypertensive rats + icariin group (icariin 10 mg/kg x d dissolved in 1 ml normal saline and given by gavage). Four weeks later, the maximum intracavernous pressure/mean arterial pressure, platelet count, mean platelet volume, platelet distribution width, endothelial microparticles, endothelial progenitor cells, and vitronectin receptor were measured in each group. Results Under 3 or 5 V electrical stimulation, the maximum intracavernous pressure/mean arterial pressure in the spontaneously hypertensive rats + icariin group (0.23 +/- 0.03, 0.38 +/- 0.02) was significantly higher compared to the spontaneously hypertensive rats control group (0.12 +/- 0.02, 0.20 +/- 0.02) (p<0.05). Platelet count, mean platelet volume, and platelet distribution width in the spontaneously hypertensive rats + icariin group (1103.67 +/- 107.70 x 10(9)/L, 9.08 +/- 0.50 fl, 11.87 +/- 0.45%) were significantly lower than those in the spontaneously hypertensive rats control group (1298.00 +/- 89.54 x 10(9)/L, 9.72 +/- 0.44 fl, 13.03 +/- 0.59%) (all p < 0.05). Endothelial microparticles, endothelial progenitor cells, and vitronectin receptor in the spontaneously hypertensive rats + icariin group (1.01 +/- 0.28%, 1.53 +/- 0.65%, 2.13 +/- 0.53%) were significantly lower than those in the spontaneously hypertensive rats control group (1.58 +/- 0.19%, 2.71 +/- 0.64%, 3.76 +/- 0.52%) (all p < 0.05). Moreover, maximum intracavernous pressure/mean arterial pressure was strongly negatively correlated with platelet distribution width and vitronectin receptor (r > 0.7), and maximum intracavernous pressure/mean arterial pressure was moderately negatively correlated with mean platelet volume, endothelial microparticles, and endothelial progenitor cells (0.5 r<0.7). Conclusion Icariin may improve erectile function in spontaneously hypertensive rats by reducing the content of endothelial microparticles in blood and inhibiting the activation of the platelets. Endothelial microparticles, endothelial progenitor cells, and platelet activation-related (mean platelet volume, platelet distribution width, and vitronectin receptor) can be used as indicators for icariin to improve erectile function in spontaneously hypertensive rats.