1. Department of Physiology, Faculty of Medicine, Cairo University, Cairo, Egypt;
2. Department of Biochemistry, Faculty of Medicine, Cairo University, Cairo, Egypt;
3. Department of Histology, Faculty of Medicine, Cairo University, Cairo, Egypt;
4. Department of Animal Reproduction and Artificial Insemination, Veterinary Division, National Research Centre, Cairo, Egypt;
5. Department of Pharmacology, Faculty of Medicine, Cairo University, Cairo, Egypt;
6. Department of physiology, Cairo University Hospitals, Cairo, Egypt