Diabetes and reactivity of isolated human saphenous vein.
Helical strips of saphenous veins from diabetic (n = 8) and non-diabetic (n = 18) humans were studied in vivo for their responsiveness to several vasoactive agents. Following application of passive force (approximately 20.0 mN), venous strips from non-diabetic humans often developed spontaneous phasic contractile activity (12 out of 18 patients; 2-5 contractions/min). These intrinsic changes in force were seen in venous strips from only one diabetic patient. The phasic contractions were not altered by treatment with phentolamine, whereas the calcium channel blocker, D-600, and calcium-free solution (1.0 mM EGTA) inhibited the phasic contractions. Saphenous veins from diabetic patients developed less maximal, active tension in response to norepinephrine than those from non-diabetic patients. Contractile responses to serotonin, angiotensin II, and elevated potassium concentration in saphenous veins from diabetic patients were not different from those in veins from non-diabetic patients. These observations demonstrate attenuated development of active tension in response to alpha-adrenergic receptor activation and reduced spontaneous contractile activity in venous smooth muscle from diabetic patients.
D000368:Aged; D000804:Angiotensin II / Q000494:pharmacology; D001808:Blood Vessels / Q000187:drug effects / Q000503:physiopathology*; D003920:Diabetes Mellitus / Q000503:physiopathology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000494:pharmacology; D010646:Phentolamine / Q000008:administration & dosage; D011189:Potassium Chloride / Q000494:pharmacology; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects; D011943:Receptors, Adrenergic, beta / Q000187:drug effects; D012501:Saphenous Vein / Q000187:drug effects / Q000503:physiopathology; D012701:Serotonin / Q000494:pharmacology; D014662:Vasoconstrictor Agents / Q000494:pharmacology*
D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D014662:Vasoconstrictor Agents; D000804:Angiotensin II; D012701:Serotonin; D011189:Potassium Chloride; D009638:Norepinephrine; D010646:Phentolamine