1. Department of Medical Physiology, Faculty of Medicine, Mansoura University, Mansoura, Egypt.
2. Department of Human Anatomy, Faculty of Medicine, Mansoura University, Mansoura, Egypt.
3. Department of Biochemistry, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt.
4. Faculty of Medicine, Mansoura University, Mansoura, Egypt.
5. Chemistry and Drug Metabolism, IRP, National Institute on Drug Abuse, National Institutes of Health, Biomedical Research Center, Baltimore, MD, USA.