Altered alpha-adrenergic responses of vas deferens to noradrenaline and tyramine from rats with short- and long-term alloxan diabetes.
1. Functional and morphological abnormalities in vas deferens have been reported by both experimental and clinical studies as a cause of genital function abnormalities in diabetic males. 2. In the present study, contractile effects of noradrenaline and tyramine in isolated vas deferens from rats with short- and long-term alloxan diabetes were investigated by comparing with those from control rats. For this purpose, intrinsic activities (alpha E value) and apparent affinity constants (pD2 value) for contractile effects of noradrenaline and tyramine in the isolated rat vas deferens were calculated in normal rats and rats with short- and long-term alloxan diabetes. 3. Apparent affinity constants for contractile effects of noradrenaline in the isolated rat vas deferens were increased depending on both short- and long-term alloxan diabetes. By contrast, apparent affinity constants for contractile effects of tyramine in the isolated rat vas deferens were attenuated due to both short- and long-term alloxan diabetes. Intrinsic activities for both noradrenaline- and tyramine-induced contractions of rat vas deferens, however, were increased due to short-term diabetes and decreased due to long-term diabetes. 4. Experimental findings obtained in this study indicate that vas deferens preparations from rats with short- and long-term alloxan-induced diabetes exhibit altered alpha-adrenergic responsiveness depending on time elapsed. While short-term alloxan diabetes causes enhanced alpha-adrenergic responses in the rat vas deferens, the long-term diabetes decreases the responses in this tissue.
Oztürk
Y
Y
Department of Pharmacology, Faculty of Pharmacy, Anadolu University, Tepebaşi, Eskişehir, Turkey.
Yildizoğlu-Ari
N
N
Altan
V M
VM
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000503:physiopathology*; D007328:Insulin / Q000097:blood; D007700:Kinetics; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects* / Q000502:physiology*; D013268:Stimulation, Chemical; D013997:Time Factors; D014439:Tyramine / Q000494:pharmacology*; D014649:Vas Deferens / Q000187:drug effects* / Q000502:physiology / Q000648:ultrastructure*
D000316:Adrenergic alpha-Agonists; D001786:Blood Glucose; D007328:Insulin; D011942:Receptors, Adrenergic, alpha; D009638:Norepinephrine; D014439:Tyramine