Effect of diabetes mellitus on response of the basilar artery to activation of ATP-sensitive potassium channels.
Our goal was to determine whether responses of the basilar artery to activation of ATP-sensitive potassium channels are altered during diabetes mellitus. We measured changes in diameter of the basilar artery in vivo in non-diabetic and diabetic rats (streptozotocin; 50-60 mg/kg i.p.) in response to activation of ATP-sensitive potassium channels using aprikalim (RP 52891) and levcromakalim (BRL 38227). Aprikalim (1.0 microM) dilated the basilar artery in non-diabetic rats by 27 +/- 6%, but by only 11 +/- 3% in diabetic rats (means +/- S.E.; P < 0.05). Levcromakalim (1.0 microM) dilated the basilar artery in non-diabetic rats by 45 +/- 11%, but by only 20 +/- 5% in diabetic rats (P < 0.05). Nitroglycerin (1.0 microM) dilated the basilar artery by 20 +/- 5% in non-diabetic rats and 17 +/- 2% in diabetic rats (P > 0.05). Thus, impaired dilatation of pial arterioles in diabetic rats in response to aprikalim and levcromakalim is not related to a non-specific effect of diabetes mellitus on vasodilatation. The findings of the present study suggest that ATP-sensitive potassium channels are functional in the rat basilar artery in vivo and are altered during diabetes mellitus.
Mayhan
W G
WG
Department of Physiology and Biophysics, University of Nebraska Medical Center, Omaha 68198-4575.
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D001488:Basilar Artery / Q000033:anatomy & histology / Q000187:drug effects / Q000503:physiopathology*; D001578:Benzopyrans / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects; D019806:Cromakalim; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology*; D004305:Dose-Response Relationship, Drug; D008297:Male; D005996:Nitroglycerin / Q000494:pharmacology; D010847:Picolines / Q000494:pharmacology; D015221:Potassium Channels / Q000187:drug effects*; D011714:Pyrans / Q000494:pharmacology; D011758:Pyrroles / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D014665:Vasodilator Agents / Q000494:pharmacology
D001578:Benzopyrans; D010847:Picolines; D015221:Potassium Channels; D011714:Pyrans; D011758:Pyrroles; D014665:Vasodilator Agents; D019806:Cromakalim; C061043:aprikalim; D000255:Adenosine Triphosphate; D005996:Nitroglycerin