Data/hora: 20/06/2024 07:48:56

Biblioteca(s): 	Embrapa Gado de Leite.	
Data corrente: 	11/01/2018	
Data da última atualização: 	27/01/2023	
Autoria: 	ASCARI, I. J.; ALVES, N. G.; JASMIN, J.; LIMA, R. R.; QUINTAO, C. C. R.; OBERLENDER, G.; MORAES, E. A.; CAMARGO, L. S. de A.	
Afiliação: 	I. J. ASCARI, UFLA; N. G. ALVES, UFLA; J. JASMIN, UFRJ; Renato Ribeiro Lima, UFLA; CAROLINA CAPOBIANGO ROMANO QUINTAO, CNPGL; G. OBERLENDER, IEF Muzambinho, MG; E. A. MORAES, Universidade Federal do Vale do São Francisco; LUIZ SERGIO DE ALMEIDA CAMARGO, CNPGL.	
Título: 	Addition of insulin-like growth factor I to the maturation medium of bovine oocytes subjected to heat shock: effects on the production of reactive oxygen species, mitochondrial activity and oocyte competence.	
Ano de publicação: 	2017	
Fonte/Imprenta: 	Domestic Animal Endocrinology, v. 60, p. 50-60, 2017.	
DOI: 	10.1016/j.domaniend.2017.03.003	
Idioma: 	Inglês	
Conteúdo: 	Abstract This study was performed to investigate the effects of insulin-like growth factor-I (IGF-I) addition to in vitro maturation (IVM) medium on apoptosis, mitochondrial membrane potential, ROS production, and developmental competence of bovine oocytes subjected to heat shock. Two temperatures (conventional: 24 h at 38.5C, or heat shock: 12 h at 41C followed by 12 h at 38.5C) and 3 IGF-I concentrations (0, 25, and 100 ng/mL) were tested during IVM. The oocytes were then fertilized in vitro, and the presumptive zygotes were cultured until reaching the blastocyst stage. There was no interaction between temperature and IGF-I concentration for any variable evaluated (P > 0.05). The addition of IGF-I did not alter the proportion of nuclear maturation, TUNEL-positive oocytes and caspase-3 activity, or blastocyst proportion on Days 7 and 8 post-fertilization. Furthermore, the total number of cells and the number of cells in the inner cell mass (ICM) in the blastocyst were not altered (P > 0.05). However, IGF-I increased (P < 0.05) the mitochondrial membrane potential and the production of ROS in oocytes and decreased (P < 0.05) the proportion of apoptotic cells in the ICM in blastocysts. Heat shock increased (P < 0.05) the proportion of TUNEL-positive oocytes and ROS production and reduced (P < 0.05) the mitochondrial membrane potential. Moreover, heat shock increased (P < 0.05) the apoptosis proportion in the ICM cells. In conclusion, supplementing IVM mediumwith IGF-I may increase the mitochondrial membrane potential and ROS production in oocytes and decrease apoptosis in the ICM in blastocysts. Heat shock for 12 h compromised oocyte developmental competence and increased apoptosis within the ICM cells of the blastocysts.	
Palavras-Chave: 	Mitochondrial membrane potential; ROS production; Thermoprotection.	
Thesaurus Nal: 	DNA fragmentation; heat stress.	
Categoria do assunto: 	L Ciência Animal e Produtos de Origem Animal	
Registro original: 	Embrapa Gado de Leite (CNPGL)	
Exemplares: 	CNPGL - (23858-1) - UPC - AP - DD -  -  -  - DIS