Data/hora: 08/06/2024 07:20:24

Biblioteca(s): | Embrapa Caprinos e Ovinos.
Data corrente: | 01/08/1992
Data da última atualização: | 11/05/2023
Autoria: | TASSELL, R.; CHAMLEY, W. A.; KENNEDY, J. P.
Título: | Gonadotrophin levels and ovarian development in the neonatal ewe lamb.
Ano de publicação: | 1978
Fonte/Imprenta: | Australian Journal of Biology Science, v. 31, n. 3, p. 267-273, Jun. 1978.
DOI: | 10.1071/bi9780267
Idioma: | Inglês
Conteúdo: | Abstract: Ovarian weight has been shown to increase markedly in the newborn ewe lamb, and factors which might contribute to this growth were examined. Follicle development was studied in the ovaries of 28 lambs aged 0, 2, 4, 6, 8 and 10 weeks. Plasma samples, pituitaries and one ovary were assayed for gonadotrophin or steroid hormone content. No significant differences between age groups were found in pituitary LH concentration or mean plasma LH. Pituitary FSH concentration increased with age, except for a small decrease at 8 weeks, but no significant changes were seen in plasma FSH. Ovarian progesterone and oestradiol concentrations did not appear to be associated with follicular development. Growing follicles were most numerous at 2 weeks whilst total vesicular follicles reached a peak at 4 weeks. Most vesicular follicles were less than 1.4 mm in diameter. Advanced atresia in vesicular follicles became apparent by 4 weeks although early signs were present in younger lambs. Fluctuations in gonadotrophin levels do not appear to be responsible for variations in number and size of vesicular and growing follicles in the lamb ovary. Other possible explanations are discussed.
Palavras-Chave: | Analysis progesterone; Fisiiologia; Folículos ovarianos; Glândula pituitária; Growth; Newborn animals; Ovary; Ovary culture (animals); Ovino Reproducao.
Thesagro: | Crescimento; Endocrinologia; Estradiol; Gonadotrofina; Ovelha; Ovino; Progesterona; Reprodução.
Thesaurus Nal: | Endocrinology; Ewes; Gonadotropins; Ovarian follicles; Pituitary gland; Pituitary gonadotropins; Progesterone; Reproduction; Sheep.
Categoria do assunto: | --
Registro original: | Embrapa Caprinos e Ovinos (CNPC)

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