Effects of early protein restriction and adult obesity on rat pancreatic hormone content and glucose tolerance.
Rats were fed a diet containing either 20% ("control") or 8% ("reduced-protein") protein throughout pregnancy and lactation. Their female offspring were weaned onto the same respective diets. At 63 days of age one set of control and reduced-protein rats (n = 16 per group) underwent intraperitoneal glucose tolerance tests and one week later were killed and their pancreatic hormones extracted and measured. The reduced protein rats had better glucose tolerance (p < 0.001) and lower pancreatic insulin (p < 0.01) and amylin (p < 0.01) contents. Further sets of control and reduced-protein rats were then fed either chow or a cafeteria-style diet (n = 16 in each of the four groups). These rats underwent intraperitoneal glucose tolerance tests at 133 days of age, which showed the cafeteria-fed animals to have a worse glucose tolerance than the chow-fed animals irrespective of previous diet exposure (p < 0.0001). One week later reduced-protein rats still had lower pancreatic insulin contents (p < 0.05) (and a trend for lower amylin contents), but also had increased pancreatic glucagon contents (p < 0.05). There were no detectable differences in pancreatic somatostatin-like immunoreactivity or pancreatic polypeptide contents. These results are consistent with pancreatic beta- and alpha-cells being selectively susceptible to effects associated with early dietary protein restriction.
Petry
C J
CJ
Clinical Biochemistry Dept., University of Cambridge, UK. cjp1002@cam.ac.uk
Ozanne
S E
SE
Wang
C L
CL
Hales
C N
CN
D000682:Amyloid / Q000032:analysis; D000818:Animals; D001786:Blood Glucose / Q000032:analysis*; D001835:Body Weight; D004044:Dietary Proteins / Q000008:administration & dosage*; D005260:Female; D005934:Glucagon / Q000032:analysis; D007328:Insulin / Q000032:analysis / Q000097:blood; D058228:Islet Amyloid Polypeptide; D009765:Obesity / Q000378:metabolism*; D009929:Organ Size; D010179:Pancreas / Q000473:pathology; D010187:Pancreatic Hormones / Q000032:analysis*; D051381:Rats; D017207:Rats, Sprague-Dawley
D000682:Amyloid; D001786:Blood Glucose; D004044:Dietary Proteins; D007328:Insulin; D058228:Islet Amyloid Polypeptide; D010187:Pancreatic Hormones; D005934:Glucagon