Data/hora: 25/06/2024 06:41:17

Biblioteca(s): | Embrapa Caprinos e Ovinos.
Data corrente: | 06/11/2002
Data da última atualização: | 06/11/2002
Autoria: | ZHANG, J.; MASSMANN, G. A.; MIRABILE, C. P.; FIGUEROA, J. P.
Título: | Nonpregnant sheep uterine type I and type III nitric oxide synthase expression is differentially regulated by estrogen.
Ano de publicação: | 1999
Fonte/Imprenta: | Biology of Reproduction, v. 60, n. 5, p. 1198-1203, 1999.
Idioma: | Inglês
Conteúdo: | The aim of this study was to characterize the effect of estrogen on lhe expression of neuronal and endothelial isoforms of nitric oxide (NO) synthase (NOS) in myometrium, endometrium, and caruncle (nonglandular endometrium) in nonpregnant sheep. Twenty sheep were castrated during synchronized estrus (Days 14-16) and 4 days after surgery treated i.v. through lhe jugular with 100 ug/day of estradiol-17Betha for 5 (n = 6) or 8 (n = 6) days or with vehicle (n = 8). Nitric oxide synthase mRNA was measured by ribonuclease protection assar, and NOS protein mass was measured by Western immunoblotting. Data were analyzed by ANOVA and Tukey's testo The three distinct uterine compartments studied contained lhe mRNA and protein for lhe neuronal (type I NOS) and lhe endothelial (type 111 NOS) isoforms of NOS. However, no inducible NOS was detected. Estrogen exhibited a differential effect on NOS expression in a tissue compartment- and NOS isoform-specific manner. In myometrium and caruncles, but not in endometrium, type I NOS mRNA and protein mass increased significantly (p < 0.05) after 5 or 8 days of estrogen. In contrast, type 111 NOS increased significantly in myometrium only after 8 days, whereas in endometrium and caruncles the increase was significant in the 5-day treatment group (p < 0.05). We conclude that the expression of type I NOS and type 111 NOS in the uterus are differentially regulated by estrogen. This differential regulation suggests that the NO produced within the uterus serves more than one physiological role. In myometrium it mar be a uterorelaxant and regulate glucose utilization, and in endometrium and myometrium it mar regulate blood flow.
Thesagro: | Endocrinologia; Estrógeno; Ovino; Prenhez; Reprodução Animal; Útero.
Categoria do assunto: | --
Registro original: | Embrapa Caprinos e Ovinos (CNPC)
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