title: Opiate modulation of glucose turnover in dogs.
abstract: We examined the effect of opiate infusion and of opiate blockage on glucose turnover in the basal state, using isotope dilution techniques in trained conscious dogs (n = 5). After a primed-continuous infusion of 3-3H glucose to steady state specific activity (90 minutes), infusion of one of the following was given: D-met2 pro5 enkephalinamide (DMPE), a potent morphine-like opiate, 0.5 mus g/kg/min; naloxone, an opiate antagonist, 1.25 mg followed by 10 mus g/min; or saline control. Infusion of DMPE led to a fall in glucose from 92 +/- 3 to 87 +/- 3 mg/dL by 60 minutes (P less than 0.05), associated with a rise in glucose utilization (Rd) from 3.0 +/- 0.4 to 3.9 +/- 0.6 mg/kg/min by 30 minutes (P less than 0.05); a transient rise in glucose production (Ra; from 3.2 +/- 0.4 to 4.3 +/- 0.4 mg/kg/min; P less than 0.05). Changes in counterregulatory hormones did not account for these findings; insulin was unchanged during all infusions; glucagon showed small late rises at 75 minutes during both DMPE and naloxone infusion; cortisol rose by 30 and 15 minutes, respectively, of DMPE and naloxone infusion; epinephrine rose transiently after 5 minutes of naloxone but was unchanged during DMPE, and norepinephrine was unchanged throughout. Saline infusion had no effects on any of these indices. We conclude that a potent opiate with morphine-like effects (DMPE) can lower glucose in dogs by enhancing peripheral glucose utilization independently of hormonal changes.
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D004285:Dogs; D004745:Enkephalins / Q000494:pharmacology; D005260:Female; D005934:Glucagon / Q000097:blood; D005947:Glucose / Q000378:metabolism*; D006854:Hydrocortisone / Q000097:blood; D007328:Insulin / Q000097:blood; D009270:Naloxone / Q000494:pharmacology; D009294:Narcotics / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D004745:Enkephalins; D007328:Insulin; D009294:Narcotics; D009270:Naloxone; C028599:enkephalin, Met(2)-Pro(5)-; D005934:Glucagon; D005947:Glucose; D006854:Hydrocortisone