Academic Journal
The hepatic retinyl ester hydrolase activity is depressed at the onset of diabetes in BB rats
| العنوان: | The hepatic retinyl ester hydrolase activity is depressed at the onset of diabetes in BB rats |
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| المؤلفون: | Chen, Min, Thomson, Alan B. R., Tsin, Andrew T. C., Basu, Tapan K. |
| المصدر: | British Journal of Nutrition ; volume 89, issue 2, page 231-238 ; ISSN 0007-1145 1475-2662 |
| بيانات النشر: | Cambridge University Press (CUP) |
| سنة النشر: | 2003 |
| الوصف: | Dietary vitamin A as retinyl ester is hydrolysed and re-esterified with long-chain fatty acids in the small intestine. The esterified vitamin A is subsequently stored in the liver, where it is hydrolysed to free retinol to be transported by carrier proteins to the target tissue. A decreased availability of retinol carrier proteins has been suggested to be responsible for affecting metabolic availability of vitamin A in type 1 diabetes. Using BB Wistar rats, the present study was undertaken to examine whether the presence of a hyperglycaemic state modifies retinyl ester hydrolase (REH) activity in the intestine and the liver. At the onset of diabetes, hepatic REH enzymatic activity was significantly (P<0·05) decreased. However, REH activity remained unaffected in the small intestine, including both ileum and jejunum. Diabetes also resulted in decreased plasma and liver concentrations of retinol. An in vitro study was conducted to examine the effect of diabetes on the intestinal uptake of retinyl palmitate. Jejunum and ileum from diabetic and non-diabetic BB rats were incubated with labelled retinyl palmitate at different concentrations ranging from 32 to 256 nmol/l. The uptake of retinyl palmitate was increased in both diabetic and non-diabetic rats together with the increase of substrate concentration. However, no significant difference was observed in the uptake of retinyl palmitate between diabetic and non-diabetic rats. These present results suggest that the depressed hepatic REH activities may contribute to the diabetes-associated metabolic derangement of vitamin A. |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | English |
| DOI: | 10.1079/bjn2002753 |
| الاتاحة: | http://dx.doi.org/10.1079/bjn2002753 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0007114503000278 |
| Rights: | https://www.cambridge.org/core/terms |
| رقم الانضمام: | edsbas.E56DACE8 |
| قاعدة البيانات: | BASE |
| DOI: | 10.1079/bjn2002753 |
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