ATP Sensitive K þ Channel Subunits (Kir6.1, Kir6.2) are the Candidate Mediators Regulating Ameliorating Effects of Pulsed Magnetic Field on Aortic Contractility in Diabetic Rats Isil Ocal, 1 Mehmet B.Yilmaz, 2 * Sabriye Kocaturk-Sel, 2 TuranTufan, 2 Mehmet A. Erkoc, 2 Gamze Comertpay, 2 Hale Oksuz, 2 and Esma D. Barc 2 1 Faculty of Medicine, Department of Biophysics, Cukurova University, Adana,Turkey 2 Faculty of Medicine, Department of Medical Biology, Cukurova University, Adana, Turkey Diabetes mellitus is a metabolic disease that causes increased morbidity and mortality in developed and developing countries. With recent advancements in technology, alternative treatment methods have begun to be investigated in the world. This study aims to evaluate the effect of pulsed magnetic field (PMF) on vascular complications and contractile activities of aortic rings along with Kir6.1 and Kir6.2 subunit expressions of ATP-sensitive potassium channels (K ATP ) in aortas of controlled-diabetic and non-controlled diabetic rats. Controlled-diabetic and non-controlled diabetic adult male Wistar rats were exposed to PMF for a period of 6 weeks according to the PMF application protocol (1 h/day; intensity: 1.5 mT; consecutive frequency: 1, 10, 20, and 40 Hz). After PMF exposure, body weight and blood glucose levels were measured. Then, thoracic aorta tissue was extracted for relaxation–contraction and Kir6.1 and Kir6.2 expression experiments. Blood plasma glucose levels, body weight, and aortic ring contraction percentage decreased in controlled-diabetic rats but increased in non-controlled diabetic rats. PMF therapy repressed Kir6.1 mRNA expression in non-controlled diabetic rats but not in controlled diabetic rats. Conversely, Kir6.2 mRNA expressions were repressed both in controlled diabetic and non- controlled diabetic rats by PMF. Our findings suggest that the positive therapeutic effects of PMF may act through (K ATP ) subunits and may frequently occur in insulin-free conditions. Bioelectromagnetics. 39:299–311, 2018. © 2018 Wiley Periodicals, Inc. Keywords: type-1 diabetic rats; pulsed magnetic field; ATP-sensitive potassium channels (K ATP ); Kir6.1; Kir6.2 INTRODUCTION Diabetes mellitus is a metabolic disease that leads to increased morbidity and mortality in devel- oped and developing countries. Diabetes causes macrovascular and microvascular complications, in- cluding acute diseases (e.g., ketoacidosis, hyperglyce- mia, and hyperosmolar non-ketotic syndrome) and chronic diseases (e.g., hypoglycemia, retinopathy, angiopathy, and peripheral neuropathy) [Schalkwijk and Stehouwer, 2005]. These vascular complications may be partially attributed to the impairment of vasomotor function of smooth muscles. In this respect, the reactivity of vascular smooth muscles to contractile and vasorelaxant agents in diabetic rats was previously studied [Kamata et al., 1989; Kobayashi and Kamata, 1999; Stanley et al., 2013]. Many studies have investigated the mechanism of the enhanced contractile response of diabetic blood ves- sels, but the mechanism of enhancement is still unknown. Grant sponsor: Cukurova University Scientific Research Support Program; grant numbers: TF 2013 BAP23, TSA-2016-6911. Conflicts of interest: None. *Correspondence to: Mehmet B. Yilmaz, Faculty of Medicine, Department of Medical Biology, Cukurova University, Balcalı Street, 01350 Adana, Turkey. E-mail: mbyilmaz@cu.edu.tr Received for review 8 August 2016; Accepted 13 December 2017 DOI: 10.1002/bem.22111 Published online 15 February 2018 in Wiley Online Library (wileyonlinelibrary.com). Bioelectromagnetics 39:299^311 (2018) ß 2018 Wiley Periodicals, Inc.