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Researchers at Jilin University, Medical Department target life sciences
2009 AUG 4 - (NewsRx.com) -- According to recent research from Changchun, People's Republic of China, "UT-B is a urea transporter protein expressed in the kidney and in many non-renal tissues including erythrocytes, brain, heart, bladder and the testis. The objective of this study was to determine the phenotype of UT-B deletion in the heart." "UT-B expression in the heart was studied in wild-type mice vs UT-B null mice by utilizing RT-PCR and Western blot. A surface electrocardiogram (ECG) recording (lead II) was measured in wild-type mice and UT-B null mice at the ages of 6, 16 and 52 weeks. For the action potential recording, the ventricular myocytes of 16 w mice were isolated and recorded by floating microelectrode method. The sodium current was recorded by the patch clamp technique. RT-PCR and Western blot showed the UT-B expression in the heart of wild-type mice. No UT-B transcript and protein was found in UT-B null mice. The ECG recording showed that the P-R interval was significantly prolonged in UT-B null mice ((43.5 +/- 4.2), (45.5 +/- 6.9) and (43.8 +/- 7.6) ms at ages of 6, 16 and 52 weeks) vs wild-type mice ((38.6 +/- 2.9), (38.7 +/- 5.6) and (38.2 +/- 7.3) ms, P< 0.05). The atrial ventricular heart block type II and III only appeared in the aging UT-B null mice (52 w old). The amplitude of action potential and V (max) decreased significantly in UT-B null mice ((92.17 +/- 10.56) and (101.89 +/- 9.54) mV/s) vs those in wild-type mice (vs (110.51 +/- 10.38) and (109.53 +/- 10.64) mV/s, P< 0.05). The action potential duration at 50% and 90% (APD(50) and APD(90)) was significantly prolonged in UT-B null mice ((123.83 +/- 11.17) and (195.43 +/- 16.41) ms) vs that in wild-type mice ((108.27 +/- 10.85) and (171.00 +/- 15.53) ms, P< 0.05). The maximal sodium current decreased significantly in UT-B null mice (-8.80 +/- 0.92) nA vs that in wild-type mice ((-5.98 +/- 1.07) nA, P< 0.05)," wrote Y. Meng and colleagues, Jilin University, Medical Department. The researchers concluded: "These results provide the first evidence that UT-B deletion causes progressive heart block in mice." Meng and colleagues published their study in Science in China Series C - Life Sciences (Surface electrocardiogram and action potential in mice lacking urea transporter UT-B. Science in China Series C - Life Sciences, 2009;52(5):474-478). For additional information, contact X.J. Zhao, Jilin University, School Basic Medical, Dept. of Pathophysiology, Changchun 130021, People's Republic of China. Publisher contact information for the journal Science in China Series C - Life Sciences is: Science Press, 16 Donghuangchenggen North St., Beijing 100717, People's Republic of China. Keywords: People's Republic of China, Changchun, Life Sciences, Cardiology, Heart Block, Kidney, Nephrology, Jilin University, Medical Department. This article was prepared by Life Science Weekly editors from staff and other reports. Copyright 2009, Life Science Weekly via NewsRx.com.
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