Data/hora: 16/06/2024 01:42:04

Provedor de dados: | Brazilian Journal of Medical and Biological Research
País: | Brazil
Título: | Follicle profile and plasma gonadotropin concentration in pubertal female ponies
Autores: | Nogueira,G.P.
Data: | 2004-06-01
Ano: | 2004
Palavras-chave: | Follicles; FSH; LH and prepubertal fillies.
Resumo: | Twelve female ponies were examined daily for 30 days and classified as ovulating (OV; N = 6; 197 ± 6 kg) or prepubertal (PP; N = 6; 196 ± 9 kg). Follicles were detected by ultrasound and gonadotropins quantified by radioimmunoassay. The mean diameter of the largest follicles was significantly larger in OV (38 ± 1 mm) than in PP (26 ± 2 mm) but there was no difference between groups in the size of the second largest follicle. There were more small follicles (&lt;24 mm) in the PP than in the OV group, but PP fillies had a smaller number of follicles &gt;29 mm than the OV fillies. Follicle-stimulating hormone (FSH) levels did not differ between groups but PP fillies had lower luteinizing hormone (LH) peak (8 ± 1 ng/ml) and basal (4 ± 0.5 ng/ml) levels, lower peak magnitude (2 ± 0.2 ng/ml) and period average (5 ± 0.6 ng/ml) than OV fillies (32 ± 4.5, 8 ± 1.2, 17.1 ± 6, and 15 ± 2.3 ng/ml, respectively). The PP group, in contrast to the OV group, showed no relationship between FSH surge and follicle wave emergence. We conclude that an LH concentration higher than 8 ng/ml is needed for follicle growth to a preovulatory size. Wave emergence and FSH secretion seem to be independent events, probably due to an inhibitory neural system in these PP animals. PP fillies may provide a physiological model for the study of follicle wave emergence which apparently does not depend on gonadotropin levels.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2004000600018
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X2004000600018
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.37 n.6 2004
Fonte: | info:eu-repo/semantics/openAccess