title: L-arginine affects the IVM of cattle cumulus-oocyte complexes.
abstract: Nitric oxide (NO) is identified as a signaling molecule involved in many cellular or physiological functions, including meiotic maturation of cattle oocytes. This study aimed to evaluate the effect of supplementation of culture medium with the L-arginine (L-arg, NO synthesis precursor) in nuclear maturation of oocytes, concentrations of nitrate/nitrite, progesterone (P4), and 17β-estradiol (E2) in the culture medium; and the cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP) intracellular concentrations in the cumulus-oocyte complexes (COCs) during the first hours of maturation in the presence of hemisections (HSs) of the follicular wall (control -ve). The addition of 5.0-mM L-arg increased (P < 0.05) the percentage of oocytes at the germinal vesicle breakdown stage after 7 hours of cultivation compared with control -ve. All concentrations of L-arg (2.5, 5.0, and 10.0 mM) increased the percentage of oocytes that reached the metaphase I (MI) at 15 hours (P < 0.05) but do not affect the progression from MI to metaphase II (P > 0.05) at 22 hours. All concentrations of L-arg tested increased (P < 0.05) the percentage of cumulus cells with plasma membrane integrity at 22 hours of cultivation. L-arginine did not change (P > 0.05) the nitrate/nitrite, P4, and E2concentrations in relation to control -ve at any of the times tested. In immature COCs, immediately after being removed from the follicles (0 hours), the intracellular concentration of cGMP in the control -ve and treatment with 5-mM L-arg progressively decreased (P < 0.05) after the first hour of cultivation; however, COCs treated with 5.0-mM L-arg had higher concentrations of cGMP at 1 hour of cultivation (P < 0.05). The cAMP concentration of COCs supplemented or not with 5.0-mM L-arg progressively increased until 3 hours of cultivation and at, 6 hours, decreased (P < 0.05). The results show, in using this system, that (1) the mechanisms that give the oocyte the ability to restart the meiosis until MI after adding 5.0-mM L-arg do not involve changes in the concentration of nitrate/nitrite, P4, and E2in the culture medium and (2) L-arg acts on a pathway that involves changing the cGMP concentration but does not involve changing cAMP concentration. More studies are needed to assess whether the observed effects of L-arg during IVM using this system are via NO or not and what the role is in increasing the viability of cumulus cells in the resumption and progression of meiosis until MI.
authors.affiliation: Laboratory of Animal Reproduction and Breeding, State University of Norte Fluminense 'Darcy Ribeiro' (Universidade Estadual do Norte Fluminense Darcy Ribeiro-UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil.
authors.forename: D F
authors.initials: DF
authors.lastname: Dubeibe
authors.affiliation: Laboratory of Animal Reproduction and Breeding, State University of Norte Fluminense 'Darcy Ribeiro' (Universidade Estadual do Norte Fluminense Darcy Ribeiro-UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil. Electronic address: mariaclaracaldasbussiere@gmail.com.
authors.forename: M C
authors.initials: MC
authors.lastname: Caldas-Bussiere
authors.affiliation: Laboratory of Animal Reproduction and Breeding, State University of Norte Fluminense 'Darcy Ribeiro' (Universidade Estadual do Norte Fluminense Darcy Ribeiro-UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil.
authors.forename: V L
authors.initials: VL
authors.lastname: Maciel
authors.affiliation: Laboratory of Animal Reproduction and Breeding, State University of Norte Fluminense 'Darcy Ribeiro' (Universidade Estadual do Norte Fluminense Darcy Ribeiro-UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil.
authors.forename: W V
authors.initials: WV
authors.lastname: Sampaio
authors.affiliation: Laboratory of Animal Reproduction and Breeding, State University of Norte Fluminense 'Darcy Ribeiro' (Universidade Estadual do Norte Fluminense Darcy Ribeiro-UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil.
authors.forename: C R
authors.initials: CR
authors.lastname: Quirino
authors.affiliation: Laboratory of Biotechnology and Animal Reproduction, Santa Maria Federal University (Universidade Federal de Santa Maria-UFSM), Santa Maria, Rio Grande do Sul, Brazil.
authors.forename: P B D
authors.initials: PB
authors.lastname: Gonçalves
authors.affiliation: Laboratory of Biotechnology and Animal Reproduction, Santa Maria Federal University (Universidade Federal de Santa Maria-UFSM), Santa Maria, Rio Grande do Sul, Brazil.
authors.forename: M P
authors.initials: MP
authors.lastname: De Cesaro
authors.affiliation: Laboratory of Animal Reproduction and Breeding, State University of Norte Fluminense 'Darcy Ribeiro' (Universidade Estadual do Norte Fluminense Darcy Ribeiro-UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil.
authors.forename: M R
authors.initials: MR
authors.lastname: Faes
authors.affiliation: Laboratory of Animal Reproduction and Breeding, State University of Norte Fluminense 'Darcy Ribeiro' (Universidade Estadual do Norte Fluminense Darcy Ribeiro-UENF), Campos dos Goytacazes, Rio de Janeiro, Brazil.
authors.forename: C S
authors.initials: CS
authors.lastname: Paes de Carvalho
mesh_terms: D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D002417:Cattle; D054885:Cumulus Cells / Q000187:drug effects* / Q000502:physiology; D000242:Cyclic AMP / Q000235:genetics / Q000378:metabolism; D006152:Cyclic GMP / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D059471:In Vitro Oocyte Maturation Techniques / Q000379:methods / Q000662:veterinary*; D009865:Oocytes / Q000187:drug effects* / Q000502:physiology
chemical_list: D001120:Arginine; D000242:Cyclic AMP; D006152:Cyclic GMP
keywords: Block meiotic resumption; Bovine oocyte; Nitric oxide; Nucleotide; Plasma membrane integrity