Plasma B-cell tropin (ACTH22-39) concentration in lean and obese (ob/ob) mice and lean and obese (fa/fa) Zucker rats.
A method has been developed for the measurement of plasma concentrations of Beta-cell tropin (BCT), which is a potent insulinotropic and lipogenic peptide secreted by the pituitary. The method was employed to compare plasma Beta-cell tropin concentrations between lean and genetically obese (ob/ob) mice and between lean and genetically obese (fa/fa) Zucker rats. The plasma concentration in lean mice was 0.17 +/- 0.02 (5)nmole/l (mean +/- SEM, n = 5), while that in obese (ob/ob) mice was significantly higher, being 2.88 +/- 1.13 (5)nmole/l. The plasma BCT concentration in Zucker rats was 0.14 +/- 0.02 (15)nmole/l, while that in obese Zucker (fa/fa) rats was significantly higher, being 1.69 +/- 0.72 (16)nmole/l. These results explain previously observed differences in the Beta-cell tropin-like biological activity in plasma from lean and obese animals, and support the hypothesis that the peptide has a role in the development of hyperinsulinaemia and obesity.
Morton
J L
JL
Clore Laboratory for the Biological Sciences, University of Buckingham, U.K.
Davenport
M
M
Dunmore
S J
SJ
D000107:Acetylation; D000324:Adrenocorticotropic Hormone / Q000097:blood* / Q000302:isolation & purification; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008820:Mice, Obese / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood* / Q000302:isolation & purification; D011863:Radioimmunoassay; D051381:Rats; D011924:Rats, Zucker / Q000097:blood*; D012016:Reference Values
D010446:Peptide Fragments; C026834:beta-cell tropin; D000324:Adrenocorticotropic Hormone