Diabetes-induced rat tracheal segment supersensitivity to carbachol.
Contractile responses to carbachol of tracheal segments isolated (i) from rats made diabetic 4 months prior by a single intravenous injection (50 mg/kg) of streptozotocin (group B), and (ii) from diabetic rats that had been treated during the same period with a daily dose (2-4 U/animal) of long-acting insulin (group C) were compared with the contractile responses of trachea isolated from age-matched control animals (group A). Tracheal segments from group B were significantly more responsive to carbachol than those from group A or C at low, but not at high carbachol concentrations. Carbachol pD2 values were higher in group B (6.85 +/- 0.05) than in groups A (6.46 +/- 0.07) or C (6.37 +/- 0.06), but were not significantly different between groups A and C. These data indicate that diabetes induces a supersensitivity to carbachol in airway smooth muscles, possibly related to a diabetes-induced vagal autonomic neuropathy.
D000818:Animals; D002217:Carbachol / Q000494:pharmacology*; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy / Q000503:physiopathology*; D007328:Insulin / Q000627:therapeutic use; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D014132:Trachea / Q000187:drug effects*
D007328:Insulin; D002217:Carbachol