Long-term oral administration of cows' milk improves insulin sensitivity in rats fed a high-sucrose diet.
We evaluated the effects of long-term daily cows' milk (CM) administration on insulin resistance induced by a high-sucrose diet. F344 rats, aged 3 weeks, were divided into two groups according to diet (dextrin-fed v. sucrose-fed). These groups were further divided into two groups receiving either CM or artificial milk (AM; isoenergetic emulsion of egg white protein, maltose, lard and minerals). Rats were fed a sucrose- or dextrin-based diet for 7 weeks and orally administered CM or AM at 25 ml/kg following an 8 h fast on a daily basis. Insulin sensitivity was evaluated via postprandial changes in serum glucose and insulin, oral glucose tolerance tests, and fasting serum insulin and fructosamine concentrations. The sucrose-fed rats showed an overall decrease in insulin sensitivity, but postprandial insulin levels were lower in the CM-treated subgroup than in the AM-treated subgroup. Peak serum glucose and insulin concentrations were highest in the sucrose-fed rats, but CM administration reduced peak glucose and insulin values in comparison with AM administration. By area under the curve analysis, insulin levels after feeding and glucose loads were significantly lower in the CM-treated groups than in the AM-treated groups. The CM-treated groups also demonstrated lower fasting insulin and fructosamine levels than the AM-treated groups. Improved insulin sensitivity due to CM administration seemed to be associated with reduced duodenal GLUT2 mRNA levels and increased propionate production within the caecum.
Matsumoto
Megumi
M
Meiji Dairies Research Chair, Creative Research Initiative Sousei (CRIS), Hokkaido University, Sapporo, Hokkaido, Japan. matsumeg@cris.hokudai.ac.jp
Inoue
Ryo
R
Tsuruta
Takeshi
T
Hara
Hiroshi
H
Yajima
Takaji
T
D000144:Acids, Acyclic / Q000378:metabolism; D000824:Animal Nutritional Physiological Phenomena / Q000502:physiology; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002432:Cecum / Q000378:metabolism / Q000382:microbiology; D004032:Diet; D019422:Dietary Sucrose / Q000008:administration & dosage*; D019270:Fructosamine / Q000097:blood; D005766:Gastrointestinal Contents / Q000737:chemistry; D005951:Glucose Tolerance Test / Q000379:methods; D051272:Glucose Transporter Type 1 / Q000378:metabolism; D051273:Glucose Transporter Type 2 / Q000378:metabolism; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology*; D007421:Intestine, Small / Q000378:metabolism; D008297:Male; D008892:Milk; D019518:Postprandial Period / Q000502:physiology; D052336:Proglucagon / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D014280:Triglycerides / Q000097:blood
D000144:Acids, Acyclic; D001786:Blood Glucose; D019422:Dietary Sucrose; D051272:Glucose Transporter Type 1; D051273:Glucose Transporter Type 2; D007328:Insulin; D014280:Triglycerides; D019270:Fructosamine; D052336:Proglucagon