The Effect of Chronic Alcohol Intake on Insulin Secretion in NIDDM Rats

Kim, Mi Jin; Shim, Myoung Sook; Kim, Mun Kyu; Kang, Dong Gu; Park, Hyung Suk; Chung, Sang Man; Hwang, Tae Sun; Shin, Young Goo; Chin, Choon Jo; Chung, Choon Hee

Abstract

BACKGROUND: The effect of alcohol on glucose metabolism is dependent on the daily amount of alcohol ingestion and the timing of intake. Heavy alcohol consumption in the fasting state may lead to serious hypoglycemia, whereas an excessive alcohol intake during meals may lead to hyperglycemia. In Korea, AIDDM (atypical insulin dependent diabetes mellitus) which shows firstly similar to the NIDDM and progresses slowly into IDDM is related to heavy alcohol drinking. So we studied that the effect of chronic alcohol intake on insulin secretion of beta cell in streptozotocin (STZ)-induced non-insulin dependent diabetic Sprangue- Dawley rats.
METHODS
40 male newborn (12 hours old) Sprague-Dawley rats were made diabetic by streptozotocin (50 mg/kg, intraperitoneal injection) and 20 male newborn (12 hours old) Sprague-Dawley rats were injected by citrate buffer solution. At 14 weeks old, diabetic group were confirmed by intraperitoneal glucose tolerance test (30% D/W, 2 g/kg). After that, diabetic group were divided into two groups. One group were fed on 5% ethanol and the other group were fed on water for 8 weeks. Control groups were divided into two groups. One group were fed on 5% ethanol and the other group were fed on water for 8 weeks. All rats were divided into 4 groups; group I: diabetic and 5% ethanol, group II: non- diabetic and 5% ethanol, group III: diabetic and water, group IV: non-diabetic and water. At the age of 22 weeks, we determined insulin level among 4 groups. After we extracted pancreas, determined the ratio of area of beta cell to islet cell.
RESULTS
1) There was no difference of weight among 4 groups in 22 week old rats. 2) Group I freely ingested 2.08g (5.50 g/kg/day) ethanol daily and group II ingested 2.04g (4.89g/kg/day) ethanol daily. 3) Plasma insulin levels of group I were lower than those of group III but not significant. 4) Plasma insulin levels of group II were higher than those of group IV but not significant. 5) In the light microscopic findings of pancreas, the ratios of area of beta cells to islet cells in group I were the lowest but not significant.
CONCLUSION
These findings suggested that chronic moderate alcohol ingestion in NIDDM rats didn't impair insulin secretion and morphology of pancreatic beta cells.