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Asian Journal of Andrology (2012) 14, 481-486; doi:10.1038/aja.2011.161; published online 27 February 2012
Mobilisation of endothelial progenitor cells: one of the possible mechanisms involved in the chronic administration of melatonin preventing erectile dysfunction in diabetic rats
Xue-Feng Qiu1, Xiao-Xin Li1,2, Yun Chen1, Hao-Cheng Lin1, Wen Yu1, Run Wang3 and Yu-Tian Dai1
1 Department of Urology, Affiliated Drum Tower Hospital, School of Medicine, Nanjing University, Nanjing 210008, China
2 Department of Urology, Nantong Hospital of Traditional Chinese Medicine, Nantong 226001, China
3 Department of Urology, University of Texas Medical School at Houston and M. D. Anderson Cancer Center, Houston, Texas 77030, USA
Correspondence: Professor YT Dai, (ytdai@hotmail.com); Professor R Wang, (run.wang@uth.tmc.edu)
Received 27 June 2011; Revised 8 August 2011; Accepted 27 August 2011
Advance online publication 27 February 2012.
| Abstract |
Diabetes-induced oxidative stress plays a critical role in the mobilisation of endothelial progenitor cells (EPCs) from the bone marrow to the circulation. This study was designed to explore the effects of chronic melatonin administration on the promotion of the mobilisation of EPCs and on the preservation of erectile function in type I diabetic rats. Melatonin was administered to streptozotocin-induced type I diabetic rats. EPCs levels were determined using flow cytometry. Oxidative stress in the bone marrow was indicated by the levels of superoxide dismutase and malondialdehyde. Erectile function was evaluated by measuring the intracavernous pressure during an electrostimulation of the cavernous nerve. The density of the endothelium and the proportions of smooth muscle and collagen in the corpus cavernosum were determined by immunohistochemistry. The administration of melatonin increased the superoxide dismutase level and decreased the malondialdehyde level in the bone marrow. This effect was accompanied by an increased level of circulating EPCs in the diabetic rats. The intracavernous pressure to mean arterial pressure ratio of the rats in the treatment group was significantly greater, compared with diabetic control rats. The histological analysis demonstrated an increase in the endothelial density of the corpus cavernosum after the administration of melatonin. However, melatonin treatment did not change the proportions of smooth muscle and collagen in the corpus cavernosum of diabetic rats. Chronic administration of melatonin has a beneficial effect on preventing erectile dysfunction (ED) in type I diabetic rats. Promoting the mobilisation of EPCs is one of the possible mechanisms involved in the improvement of ED.
Keywords: diabetes; endothelial progenitor cells; erectile dysfunction; melatonin; mobilisation; oxidative stress |
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