Endothelin-1 induces insulin resistance in conscious rats.
Since endothelin-1 (ET-1) might regulate insulin secretion and glucose metabolism, we carried out experiments to study the effect of ET-1 in conscious rats by injecting ET-1 (0.5 or 1.0 microgram/100 g body weight, i.p.) and examining the plasma glucose (PG) and insulin (PI) concentrations and PG/PI ratios continuously for 3 hours after the injection. Compared to the saline controls, ET-1 increased PG and PG/ P1 ratios in a dose-dependent manner. Oral glucose tolerance test (OGTT) performed at 30 min after the injection showed that PG levels stayed significantly higher in rats preinjected with ET-1 than rats with saline injection, although the change in PI levels was not different. Simultaneous infusion of glucose and insulin to somatostatin-primed rats with ET-1 or saline injection resulted in significantly higher steady state plasma glucose (SSPG) levels and SSPG/PI ratios in rats injected with ET-1 than control rats with saline. These results unequivocally indicated that intraperitoneally administered ET-1 induces insulin resistance in conscious rats.
Juan
C C
CC
Department of Physiology, National Yang-Ming University, Taipei, Taiwan, Republic of China.
Fang
V S
VS
Huang
Y J
YJ
Kwok
C F
CF
Hsu
Y P
YP
Ho
L T
LT
D000818:Animals; D001120:Arginine / Q000378:metabolism; D001786:Blood Glucose / Q000032:analysis; D019332:Endothelin-1 / Q000494:pharmacology*; D005951:Glucose Tolerance Test; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
D001786:Blood Glucose; D019332:Endothelin-1; D007328:Insulin; D009569:Nitric Oxide; D001120:Arginine