Effect of intrathecal morphine on the fate of glucose. Comparison with effects of insulin and xanthan gum in mice.
The hypoglycemic effect of morphine (40 micrograms) injected intrathecally (i.t.) was studied with regard to disposition of i.v. [14C]glucose and [3H]2-deoxyglucose and was compared with the effects of two other hypoglycemic agents, insulin (1 IU/kg, s.c.) and xanthan gum (50 mg/kg, i.p.). Mice given i.t. morphine or s.c. insulin exhaled a greater amount of 14CO2 from i.v. [14C]glucose than did control mice given i.t. saline, whereas there was less 14CO2 expiration in xanthan-treated mice. In morphine-treated mice there was less 14C in liver, brain and blood, and more 3H in kidney and hindleg muscle than in control mice. Insulin-treated mice had more 14C in muscle, less 14C in liver, brain, kidney and blood, and less 3H in liver and blood. In xanthan-treated mice, levels of both radiolabels were higher in liver, brain and kidney. Much lower glycogen content in muscle and depletion of liver glycogen occurred in morphine-treated mice, compared with control mice. Spinal transection completely inhibited the hypoglycemic effect of morphine, whereas adrenalectomy caused no inhibition. Morphine, insulin and xanthan appear to be acting by different mechanisms, although the hypoglycemic effects of both morphine and insulin appear to be due largely to an increased glucose uptake by muscle.
White
C W
CW
Department of Pharmacology and Toxicology, Medical College of Virginia/Virginia Commonwealth University, Richmond 23298-0613.
Ward
C R
CR
Dombrowski
D S
DS
Dunlow
L D
LD
Brase
D A
DA
Dewey
W L
WL
D000818:Animals; D002245:Carbon Dioxide / Q000032:analysis; D003847:Deoxyglucose / Q000378:metabolism; D005947:Glucose / Q000493:pharmacokinetics*; D006003:Glycogen / Q000378:metabolism; D007003:Hypoglycemia / Q000139:chemically induced; D007278:Injections, Spinal; D007328:Insulin / Q000494:pharmacology; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology*; D009132:Muscles / Q000378:metabolism; D011135:Polysaccharides, Bacterial / Q000494:pharmacology; D014018:Tissue Distribution
D007328:Insulin; D011135:Polysaccharides, Bacterial; D002245:Carbon Dioxide; D009020:Morphine; D006003:Glycogen; D003847:Deoxyglucose; D005947:Glucose; C002563:xanthan gum