Elevated plasma concentrations of beta-cell tropin (ACTH22-39) in diet-treated type II diabetic patients.
beta-Cell tropin, the pituitary peptide ACTH22-39, is a potent insulin secretagogue and stimulates lipogenesis in adipose tissue in rodents. Plasma beta-cell tropin was measured fasting and after glucose infusion (5 mg.kg glucose ideal body weight-1.min0-1 for 90 min) in 10 mild diet-treated non-insulin-dependent (type II) diabetic subjects and 10 control subjects (body mass index) (BMI): 26.4 +/- 3.2 and 24.1 +/- 2.0 kg/m-2, NS, fasting plasma glucose 7.8 +/- 2.7 mM and 4.7 +/- 0.3 mM, respectively). The diabetic subjects had raised fasting plasma beta-cell tropin compared with the normal subjects (geometric mean (1 SD range): 0.49 (0.25-0.96) nM and 0.17 (0.10-0.28) nM, respectively, P = 0.007). In response to the glucose infusion, plasma glucose rose higher in the diabetic subjects (mean +/- 1 SD: 13.7 +/- 3.1 and 9.6 +/- 0.9 mM, P = 0.007) and plasma insulin was impaired in the diabetic compared with the nondiabetic subjects (geometric mean (1 SD range): 14 (8-26) and 34 (18-63), P less than 0.01). beta-Cell tropin concentrations in the diabetic subjects rose to 1.31 (0.74-2.30) nM (P = 0.007), whereas beta-cell tropin did not change in the normal subjects at 0.19 (0.11-0.91) nM. There was no overlap between glucose-stimulated plasma beta-cell tropin in the two groups (P = 0.0002). Pituitary-adrenal function, as assessed by plasma cortisol, did not differ between the two groups when fasting and did not change after the glucose infusion.(ABSTRACT TRUNCATED AT 250 WORDS)
Levy
J C
JC
Clore Laboratory for the Biological Sciences, Department of Life Sciences, University of Buckingham, United Kingdom.
Morton
J L
JL
Davenport
M
M
Beloff-Chain
A
A
Turner
R C
RC
D000324:Adrenocorticotropic Hormone / Q000097:blood*; D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D001835:Body Weight; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000178:diet therapy*; D003927:Diet, Diabetic; D005260:Female; D005947:Glucose / Q000008:administration & dosage; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007262:Infusions, Intravenous; D007328:Insulin / Q000097:blood; D007515:Islets of Langerhans / Q000378:metabolism* / Q000502:physiology; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000097:blood*
D001786:Blood Glucose; D007328:Insulin; D010446:Peptide Fragments; C026834:beta-cell tropin; D000324:Adrenocorticotropic Hormone; D005947:Glucose; D006854:Hydrocortisone