Studies On Location And Regional Distribution Of Sulfonylurea Receptor In The Heart Of Nomal And Preconditioning Rat

Single or multiple brief periods of ischemia have been shown to produce a marked cardioprotection against injury produced by a subsequent prolonged ischemic injury, this phenomenon was termed ischemic preconditioning (IPC). IPC has been shown to occur in various animal species, including Humans. It consists of 2 phases, an early phase (EP) and a delayed phase (DP). The ATP-sensitive Potassiu Channel (KArp) channel has been demonstrated to be a key component of IPC. Sulfonylurea receptor (SUR) is the functional subunit of KATp. There are little reports published about the distribution of SUR in internal journal, especially under the condition of ischemia or IPC. We investigated nomal and IPC rats 2 by in vitro receptor autoradiography using H-glibenclamide as the radioligand. Through this study, the experimental parameters would be potentially useful in the research of the cardioprotectice mechanisms of IPC and in assessing the response of the myocardium to IPC with myocardial perfusion imaging. Materials and Methords The Sprague-Dawley rats were chosen to establish the IPC rat model. In vitro receptor autoradiography was used to investigate the properties of SUR in normal and JPC rats. ECG was used to monitoring the behavior of rat in JPC. And LIE staining was performed at adjacent sections. Computer assisted image analysis was performed to analyses the change of transmittance. The data was shown as x 眘 and ANOVA analyses was performed by SPSS software. Results 1: The distribution of SUR1 was homologous in different regions in normal adult and 7 days old rats rat heart. 2: The distribution of SUR2 was heterogeneous in different regions in normal adult rats myocardium. There are similar expressive densities of H3-glibenclamide in left ventricle, septum and papillary muscles (P>O.05). The ventricle, left septum and papillary muscles are highly labelled than right ventricle and atrium (PO.05). Septum and papillary muscles were highly labelled than left and right ventricle and atrium (PO.O5). 5: The expressive density of SUR2 in regions of ischemia was lower than non-ischemic regions (P