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実験的脂肪肝牛における血清リポタンパク質とハプトグロビン
| Title: | 実験的脂肪肝牛における血清リポタンパク質とハプトグロビン |
| Other Titles: | Serum Lipoproteins and Haptogllobin in Cows with Experimentally lnduced Fatty Liver |
| Authors: | 内田, 英二1 Browse this author |
| Authors(alt): | Uchida, Eiji1 |
| Issue Date: | 26-Dec-1994 |
| Publisher: | Hokkaido University |
| Abstract: | The previous studies of fatty liver in cows have been mainly focused on natural cases, and there have been no reports on experimentally induced fatty liver. Ethionine, an analogue of methionine, is known to induce fatty liver in rats by inhibiting the biosynthesis of some proteins such as apolipoproteins. The purpose of the study reported here is to induce fatty liver in cows by administration of ethionine, to determine the role of serum lipoproteins and haptoglobin (Hp), and to make critical commentary upon possible factors for the development of fatty liver in cows at peripartum. The results obtained were summarized as follows : 1) Intraperitoneal injection of ethionine at a dose of 25mg/kg of body weight at 1 week intervals resulted in a significant increase in liver triglyceride (TG) content. 2) The serum level of several apolipoproteins was found to decrease, in particular, apolipoprotein B-100 (apoB-100) in very low density (0.95 to 1.006 g/ml) lipoprotein and in low density (1.006 to 1.063 g/ml) lipoprotein fractions. Decreased concentration of apolipoprotein A-I in high density (1.063 to 1.210 g/ml) lipoprotein was also observed, although not as distinctly as with apoB-100 . 3) The decrease of serum apoB-100 concentration in the two lipoprotein fractions was correlated to the decreased TG concentration in the respective fractions . 4) Serum levels of total cholesterol and phospholipid in low and high density lipoprotein fractions were decreased. The decrease in cholesterol was attributed to the reduced concentration of cholesterol esters. 5) In order to assess the possible association of serum Hp with fatty liver, serum Hp concentration was evaluated by the single radial immunodiffusion method after ethionine administration. Haptoglobin concentration was found to be increased in the sera of ethionine-administered cows. 6) Serumc ortisol concentration was also increased in ethionine-treated cows. 7) Among various serum parameters measured before and after parturition, Hp, cortisol and nonesterified fatty acids were increased, and apoB-100 and TG were decreased at parturition. Thus, ethionine administration to cows can induce biochemical alterations quite similar to those seen in natural cases of fatty liver; that is, an increase in hepatic triglyceride content, a decreased level of serum apolipoprotein and a significant rise of serum Hp level. These results suggest that ethionine administration provides a useful model for the study of the pathogenesis of fatty liver in cows. It was also suggested that serum Hp is correlated with the development of fatty liver in cows, and may be one of the markers for the diagnosis of fatty liver in cattle. |
| Conffering University: | 北海道大学 |
| Degree Report Number: | 乙第4681号 |
| Degree Level: | 博士 |
| Degree Discipline: | 獣医学 |
| Type: | theses (doctoral) |
| URI: | http://hdl.handle.net/2115/51225 |
| Appears in Collections: | 学位論文 (Theses) > 博士 （獣医学）
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Submitter: 内田 英二
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