DETECTION, LOCALIZATION AND IDENTIFICATION OF ISOFORMS OF THE NITRIC OXIDE SYNTHASE IN EQUINE SPERM

• Grant number: 10/01916-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2010
• End date: March 31, 2011
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Reproduction
• Principal Investigator: André Furugen Cesar de Andrade
• Grantee: Rafaela Nogueira Rodrigues Cardoso
• Host Institution: Faculdade de Medicina Veterinária e Zootecnia (FMVZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Mammals' sperm must go through a serial of physiologically changes before it became able to fertilize the oocyte. These changes are called capacitation and include the production of oxygen reactive species, like the nitric oxide, and most part of then are originated from the normal metabolism of the cell. Nitric Oxide (NO) is synthesized in vivo during the conversion of L-arginine to L-citruline though oxidative reactions catalyzed by the enzyme nitric oxide synthase (NOS). Three isoforms of NOS have been described and classified depending on tissue of origin, function and structural proprieties. There are two constituent and calcium dependent: neuronal (nNOS) and endothelial (eNOS). The third one is inducible (iNOS) and calcium-independent isoform. The localization and function of some NOS isoforms have been detected in spermatozoa of different species, such as bulls, rats and humans, presents in acrossome and tail of bull and human spermatozoa. Besides there are few studies about NO/NOS in equines, there is a growing evidence of it importance in reproduction process. Due to the absence in literature showing NOS isoforms in equine, this project objective is to verify the NOS isoforms that are, or not, expressed, using techniques of immunohistochemical and western blotting.