Calmodulin content and in vitro contractility of duodenum from streptozotocin-induced diabetic rats: effects of insulin therapy and calmodulin antagonism.
The effects of experimental diabetes and insulin treatment on the decreased reactivity of isolated rat duodenum to KCl and calmidazolium, a specific calmodulin antagonist, were examined. After 8 weeks of streptozotocin diabetes, the contractile effect of KCl and the non-competitive antagonistic effect of calmidazolium against KCl on isolated rat duodenum were decreased. Calmodulin levels, as measured by radioimmunoassay, were also found to the decreased in duodenum from streptozotocin-diabetic rats. Neither impaired reactivity to KCl nor decreased calmodulin levels in diabetic rat duodenum were corrected by treatment with insulin (10 IU/kg for 20 days). Following insulin treatment, there was only a partial correction in the antagonistic effect of calmidazolium as shown by the increase in non-competitive antagonist affinity constant.
Oztürk
Y
Y
Department of Pharmacology, Faculty of Pharmacy, Anadolu University, Ankara, Turkey. YOZTURK@vm.baum.anadolu.edu.tr
Aydin
S
S
Ozçelikay
A T
AT
Altan
V M
VM
Yildizoğlu-Ari
N
N
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002147:Calmodulin / Q000037:antagonists & inhibitors / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy / Q000378:metabolism / Q000503:physiopathology*; D004386:Duodenum / Q000187:drug effects* / Q000378:metabolism*; D007004:Hypoglycemic Agents / Q000627:therapeutic use*; D066298:In Vitro Techniques; D007328:Insulin / Q000097:blood / Q000627:therapeutic use*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar
D001786:Blood Glucose; D002147:Calmodulin; D007004:Hypoglycemic Agents; D007328:Insulin; D011189:Potassium Chloride