Browsing by Author "Heinle, Helmut (7003342814)"

Because adrenergic contractions can contribute to the development of life-threatening spasm of coronary artery bypass graft, this study was performed to investigate the effect of adenosine 3-phosphate (ATP)-sensitive K channel (KATP) opener P1075 on contractions of isolated human saphenous vein (HSV) and human internal mammary artery (HIMA). Phasic contractions were evoked by electric field stimulation (20 Hz) and noradrenaline. The sustained contractions were evoked by phenylephrine. The presence of pore-forming Kir6.1 and Kir6.2 subunits of the KATP channels in the HIMA and only Kir6.2 in the HSV was confirmed immunomorphologically. P1075 inhibited in the HSV only, the electrical field stimulation contractions more strongly than noradrenaline contractions. In addition, the phenylephrine contractions of HSV were more sensitive to P1075 in comparison to those of HIMA. Glibenclamide, a K ATP channel blocker antagonized the vasodilatation produced by P1075 in both grafts differently, because its effect was more prominent on the P1075-induced inhibition of contractions of HSV than of HIMA. We conclude that P1075 has a vasorelaxant effect and inhibited adrenergic contractions of the tested grafts. This effect is graft and vasoconstrictor selective and seems to be mediated by Kir6.1- and/or Kir6.2-containing KATP channels. Thus, P1075 can be considered as a potential drug in the prevention of graft spasm. © 2011 by Lippincott Williams & Wilkins.

Because adrenergic contractions can contribute to the development of life-threatening spasm of coronary artery bypass graft, this study was performed to investigate the effect of adenosine 3-phosphate (ATP)-sensitive K channel (KATP) opener P1075 on contractions of isolated human saphenous vein (HSV) and human internal mammary artery (HIMA). Phasic contractions were evoked by electric field stimulation (20 Hz) and noradrenaline. The sustained contractions were evoked by phenylephrine. The presence of pore-forming Kir6.1 and Kir6.2 subunits of the KATP channels in the HIMA and only Kir6.2 in the HSV was confirmed immunomorphologically. P1075 inhibited in the HSV only, the electrical field stimulation contractions more strongly than noradrenaline contractions. In addition, the phenylephrine contractions of HSV were more sensitive to P1075 in comparison to those of HIMA. Glibenclamide, a K ATP channel blocker antagonized the vasodilatation produced by P1075 in both grafts differently, because its effect was more prominent on the P1075-induced inhibition of contractions of HSV than of HIMA. We conclude that P1075 has a vasorelaxant effect and inhibited adrenergic contractions of the tested grafts. This effect is graft and vasoconstrictor selective and seems to be mediated by Kir6.1- and/or Kir6.2-containing KATP channels. Thus, P1075 can be considered as a potential drug in the prevention of graft spasm. © 2011 by Lippincott Williams & Wilkins.

The effect of resveratrol on vasculature of diabetic animal is not defined. This study was aimed at evaluating how alloxan-induced diabetes alters the relaxation of the isolated rat renal artery (RA) to resveratrol and determining whether prolong hyperglycemia modifies the expression of potassium (K) channels in the wall of RA. Diabetes reduced the sensitivity to resveratrol in RA. According to K channel blocker affinity, it seems that different subtype of K channels were involved in the resveratrol-induced relaxation of RA of normal rats and only voltage-sensitive Kv1 channels took part in the resveratrol effect on the RA of diabetic rats. Endothelial dysfunction developed during diabetes led to down-regulation of the expression of almost all tested K channels, while up-regulation of Kv1.3 channel expression was only noticeable. Having in mind that Kv1.3 channels have a prominent role in insulin signalling, these results suggest renovascular protective effect of resveratrol in diabetes. © 2018 Elsevier Ltd

The effect of resveratrol on vasculature of diabetic animal is not defined. This study was aimed at evaluating how alloxan-induced diabetes alters the relaxation of the isolated rat renal artery (RA) to resveratrol and determining whether prolong hyperglycemia modifies the expression of potassium (K) channels in the wall of RA. Diabetes reduced the sensitivity to resveratrol in RA. According to K channel blocker affinity, it seems that different subtype of K channels were involved in the resveratrol-induced relaxation of RA of normal rats and only voltage-sensitive Kv1 channels took part in the resveratrol effect on the RA of diabetic rats. Endothelial dysfunction developed during diabetes led to down-regulation of the expression of almost all tested K channels, while up-regulation of Kv1.3 channel expression was only noticeable. Having in mind that Kv1.3 channels have a prominent role in insulin signalling, these results suggest renovascular protective effect of resveratrol in diabetes. © 2018 Elsevier Ltd