Consulta: creatorFacets:"HAMANO, Seizo"
Registros recuperados: 4
Data/hora: 17/06/2024 15:46:49

Gene Expression of 11β-HSD and Glucocorticoid Receptor in the Bovine (Bos taurus) Follicle During Follicular Maturation and Atresia : The Role of Follicular Stimulating Hormone
Provedor de dados: 19
Autores: TETSUKA, Masafumi; NISHIMOTO, Hiromi; MIYAMOTO, Akio; OKUDA, Kiyoshi; HAMANO, Seizo; 手塚, 雅文; 宮本, 明夫.
Glucocorticoids modulate ovarian function in cattle. However, their regulatory mechanisms have not been fully elucidated. In the present study, we examined gene expression of two glucocorticoid-metabolizing enzymes, a bidirectional 11β-HSD type 1 (11HSD1) and a dehydrogenase 11β-HSD type 2 (11HSD2), and glucocorticoid receptor (GR) in bovine follicles during follicular maturation and atresia. Granulosa cells (GCs) and theca interna layers (TIs) were harvested from follicles classified as small growing, dominant, preovulatory, early atretic and late atretic follicles. The expression levels of 11HSD1, 11HSD2 and GR mRNA were quantified by real-time PCR. In the healthy follicles, expression of 11HSD1 mRNA increased as follicles matured, both in GCs and TIs. A...
Palavras-chave: Bovine; Cortisol; 11β-HSD; Follicle; Glucocorticoid receptor; MRNA.
Ano: 2010
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2810

Relationship between Ovarian Weight and Follicular Population in Heifers
Provedor de dados: 19
Autores: MURASAWA, Maya; TAKAHASHI, Tsuyoshi; NISHIMOTO, Hiromi; YAMAMOTO, Sawa; HAMANO, Seizo; TETSUKA, Masafumi; 手塚, 雅文.
The size of the ovary varies substantially among cattle. This variation may influence the potential of the ovary to produce follicles. In the present study, we examined whether a relationship exists between the weight of the ovary and the number of antral follicles ≥1 mm. Paired ovaries were obtained from Holstein × Japanese Black F1 heifers. Follicles were classified into three size categories (small: 1.0 - &lt; 5.0 mm, medium: 5.0 - &lt; 8.5 mm and large: ≥ 8.5 mm), and the number of follicles in each category was recorded. Large variations in the weight of ovaries and the number of follicles were observed among animals. Significant positive correlations (r≥0.4, P&lt;0.001) were found between the weight of intact ovaries and the number of follicles in...
Palavras-chave: Cattle; Follicular development; Follicular population; Ovarian weight.
Ano: 2005
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/3035

Classification of Bovine Follicles Based on the Concentrations of Steroids, Glucose and Lactate in Follicular Fluid and the Status of Accompanying Follicles
Provedor de dados: 19
Autores: NISHIMOTO, Hiromi; HAMANO, Seizo; HILL, Glen Alan; MIYAMOTO, Akio; TETSUKA, Masafumi; 宮本, 明夫; 手塚, 雅文.
A simple and clear means to identify the physiological status of follicles is essential for study of follicular biology. In the present study, we verified a novel classification procedure based on analysis of the follicular population and glucose concentration in follicular fluid (FF) as an alternative method to classify bovine follicles. Paired ovaries were collected from heifers, and the number of follicles and stage of the CL were recorded. Follicles were initially divided into the following 3 groups according to diameter and the ratio of E2 and P4 (E/P): E2 active (E-A: E/P≥1), E2 inactive (E-I: E/P&lt;1, ≥8.5 mm) and small follicles (E/P&lt;1, &lt;8.5 mm). E-A follicles were easily identified as E2-rich dominant follicles and were further classified...
Palavras-chave: Bovine; Follicular fluid; Follicle classification; Glucose; Lactate; Steroid.
Ano: 2009
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2828

Bovine Oocytes and Early Embryos Express mRNA Encoding Glycerol Kinase but Addition of Glycerol to the Culture Media Interferes with Oocyte Maturation
Provedor de dados: 19
Autores: OKAWARA, Sumika; HAMANO, Seizo; TETSUKA, Masafumi; 手塚, 雅文.
Glycerol plays multi-functional roles in cellular physiology. Other than forming the backbone molecule for glycerophospholipid and triglyceride (TG), glycerol acts as an energy substrate for glycolysis. Spermatozoa are known to utilize glycerol for energy production, but there are no reports of this in oocytes. In this study, the value of glycerol as an energy substrate for bovine oocyte maturation (Exp. 1) and the gene expression of glycerol kinase (GK), an enzyme crucial for cellular glycerol utilization, in bovine oocytes and early embryos (Exp. 2) were examined. In Exp. 1, in vitro maturation (IVM) was conducted using synthetic oviduct fluid supplemented with/without glucose (1.5 mM) and/or glycerol (1.0 mM), and maturation rate, degree of cumulus...
Palavras-chave: Bovine; Embryo; Glycerol; Glycerol kinase (GK); Oocyte maturation.
Ano: 2009
URL: http://ir.obihiro.ac.jp/dspace/handle/10322/2829