Klein Gordon L, Enkhbaatar Perenlei, Traber Daniel L, Buja L Max, Jonkam Colette C, Poindexter Brian J, Bick Roger J
Department of Pediatrics, University of Texas Medical Branch Galveston, Galveston, TX, United States.
Burns. 2008 May;34(3):370-5. doi: 10.1016/j.burns.2007.04.010. Epub 2007 Sep 14.
Due to up-regulation of the parathyroid gland calcium-sensing receptor (CaR), burned children have hypocalcemic hypoparathyroidism, and decreased myocardial contractility. Our aim was to localize the CaR in the heart and measure receptor density changes due to burns. Heart and aorta samples from sheep subjected to 40% burn or sham conditions were probed for CaR via fluorescence microscopy. CaR was localized to endocardial endothelium, myocardial microvasculature, and fibroblasts and vessels of the aortic adventitia. CaR was not found in cardiomyocytes or smooth muscle cells. No differences in density of CaR or beta-adrenergic receptors were noted. No differences in CaR distribution were seen in the myocardium or aorta, in contrast to the parathyroid where burn injury up-regulates CaR. We suggest that CaR has a local, tissue-specific role, and functions in vascular calcium sensing for intravascular calcium deposition or regulation of other calcium channels after trauma or burn.
由于甲状旁腺钙敏感受体（CaR）上调，烧伤儿童会出现低钙性甲状旁腺功能减退，并伴有心肌收缩力下降。我们的目的是确定心脏中CaR的位置，并测量烧伤导致的受体密度变化。通过荧光显微镜对40%烧伤或假手术条件下绵羊的心脏和主动脉样本进行CaR检测。CaR定位于心内膜内皮、心肌微血管以及主动脉外膜的成纤维细胞和血管。在心肌细胞或平滑肌细胞中未发现CaR。CaR或β-肾上腺素能受体的密度没有差异。与甲状旁腺不同，烧伤会使甲状旁腺的CaR上调，而在心肌或主动脉中未观察到CaR分布的差异。我们认为CaR具有局部、组织特异性作用，在创伤或烧伤后，其在血管钙感知中发挥作用，用于血管内钙沉积或调节其他钙通道。
