Influence of Ramadan-type fasting on enzymes of carbohydrate metabolism and brush border membrane in small intestine and liver of rat used as a model.
During Ramadan, Muslims the world over abstain from food and water from dawn to sunset for a month. We hypothesised that this unique model of prolonged intermittent fasting would result in specific intestinal and liver metabolic adaptations and hence alter metabolic activities. The effect of Ramadan-type fasting was studied on enzymes of carbohydrate metabolism and the brush border membrane of intestine and liver from rat used as a model. Rats were fasted (12 h) and then refed (12 h) daily for 30 d, as practised by Muslims during Ramadan. Ramadan-type fasting caused a significant decline in serum glucose, cholesterol and lactate dehydrogenase activity, whereas inorganic phosphate increased but blood urea N was not changed. Fasting resulted in increased activities of intestinal lactate (+34%), isocitrate (+63%), succinate (+83%) and malate (+106%) dehydrogenases, fructose 1,6-bisphosphatase (+17%) and glucose-6-phosphatase (+22%). Liver lactate dehydrogenase, malate dehydrogenase, glucose-6-phosphatase and fructose 1,6-bisphosphatase activities were also enhanced. However, the activities of glucose-6-phosphate dehydrogenase and malic enzyme fell significantly in the intestine but increased in liver. Although the activities of alkaline phosphatase, gamma-glutamyl transpeptidase and sucrase decreased in mucosal homogenates and brush border membrane, those of liver alkaline phosphatase, gamma-glutamyl transpeptidase and leucine aminopeptidase significantly increased. These changes were due to a respective decrease and increase of the maximal velocities of the enzyme reactions. Ramadan-type fasting caused similar effects whether the rats fasted with a daytime or night-time feeding schedule. The present results show a tremendous adaptation capacity of both liver and intestinal metabolic activities with Ramadan-type fasting in rats used as a model for Ramadan fasting in people.
Farooq
Neelam
N
Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, 202002, UP, India.
Priyamvada
Shubha
S
Arivarasu
N A
NA
Salim
Samina
S
Khan
Farah
F
Yusufi
Ahad Noor Khan
AN
D000222:Adaptation, Physiological; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D050260:Carbohydrate Metabolism; D005215:Fasting / Q000378:metabolism*; D006597:Fructose-Bisphosphatase / Q000378:metabolism; D005952:Glucose-6-Phosphatase / Q000378:metabolism; D007421:Intestine, Small / Q000201:enzymology / Q000378:metabolism* / Q000648:ultrastructure; D007514:Islam; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D007931:Leucyl Aminopeptidase / Q000378:metabolism; D008099:Liver / Q000201:enzymology / Q000378:metabolism* / Q000648:ultrastructure; D008291:Malate Dehydrogenase / Q000378:metabolism; D008871:Microvilli / Q000201:enzymology* / Q000378:metabolism; D023421:Models, Animal; D051381:Rats; D017208:Rats, Wistar; D013385:Succinate Dehydrogenase / Q000378:metabolism; D005723:gamma-Glutamyltransferase / Q000378:metabolism
D007770:L-Lactate Dehydrogenase; D008291:Malate Dehydrogenase; D013385:Succinate Dehydrogenase; D005723:gamma-Glutamyltransferase; D000469:Alkaline Phosphatase; D006597:Fructose-Bisphosphatase; D005952:Glucose-6-Phosphatase; D007931:Leucyl Aminopeptidase