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Disease Markers
Volume 2014, Article ID 108106, 7 pages
Research Article

Potential Novel Biomarkers for Diabetic Testicular Damage in Streptozotocin-Induced Diabetic Rats: Nerve Growth Factor Beta and Vascular Endothelial Growth Factor

1Department of Biochemistry, Dokuz Eylul University, 35340 Izmir, Turkey
2Department of Physiology, Dokuz Eylul University, 35340 Izmir, Turkey
3Division of Behavioral Physiology, Department of Physiology, School of Medicine, Dokuz Eylul University, 35340 Izmir, Turkey
4Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA
5Department of Psychiatry, Mayo Clinic Health System, Waycross, GA 31501, USA
6College of Natural and Applied Sciences, Department of Biotechnology, Ege University Bornova, 35920 Izmir, Turkey
7College of Vocational School of Health Services, School of Medicine, Dokuz Eylul University, 35340 Izmir, Turkey
8College of Physical Therapy and Rehabilitation, Dokuz Eylul University, Balcova, 35340 Izmir, Turkey

Received 29 June 2013; Revised 17 January 2014; Accepted 17 January 2014; Published 20 March 2014

Academic Editor: Mariann Harangi

Copyright © 2014 Ali Rıza Sisman et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Background. It is well known that diabetes mellitus may cause testicular damage. Vascular endothelial growth factor (VEGF) and nerve growth factor beta (NGF-β) are important neurotrophic factors for male reproductive system. Objective. We aimed to investigate the correlation between testicular damage and testicular VEGF and NGF-β levels in diabetic rats. Methods. Diabetes was induced by streptozotocin (STZ, 45 mg/kg/i.p.) in adult rats. Five weeks later testicular tissue was removed; testicular VEGF and NGF-β levels were measured by ELISA. Testicular damage was detected by using hematoxylin and eosin staining and periodic acid-Schiff staining, and apoptosis was identified by terminal-deoxynucleotidyl-transferase-mediated dUTP nick end labeling (TUNEL). Seminiferous tubular sperm formation was evaluated using Johnsen’s score. Results. In diabetic rats, seminiferous tubule diameter was found to be decreased; basement membrane was found to be thickened in seminiferous tubules and degenerated germ cells. Additionally, TUNEL-positive cells were increased in number of VEGF+ cells and levels of VEGF and NGF-β were decreased in diabetic testes. Correlation between VEGF and NGF-β levels was strong. Conclusion. These results suggest that the decrease of VEGF and NGF-β levels is associated with the increase of the apoptosis and testicular damage in diabetic rats. Testis VEGF and NGF-β levels could be potential novel biomarkers for diabetes induced testicular damage.