My laboratory is interested in studying renal tubular acidification processes using micropuncture and microperfusion techniques. We have done detailed analysis on the passive and active driving forces of proximal and distal tubular bicarbonate transport. The cellular mechanism responsible for direct action of angiotensin II on the tubular transport has been elucidated. Another aspect of my research deals with the study of neural control of renal tubular function and the role of calcium and cyclic nucleotides in coupling between neurostimulus and response. During the past years my laboratory demonstrated that either epinephrine or norepinephrine could stimulate tubular transport processes. The effect appeared to be the result of stimulating microsomal Na-K-ATPase activity through an alpha adrenergic mechanism. Moreover, renal denervation resulted in a reduction in Na-K-ATPase and tubular transport. My laboratory has also engaged in the study of ionic channels in the renal cell membranes by using patch clamp techniques. We have identified a potassium channel in the apical membrane of the proximal tubule. The selectivity and conductance of ion channels are characterized by using on-cell and excised patch configurations. The kinetics of channel opening and closing will be analyzed. Furthermore, the changes in whole cell conductance and specific ion channel activity in response to hormone are studied.
Publications:
1. Wang, T. and Chan, Y.L.: Time and Dose-dependent effects of protein kinase C on proximal bicarbonate transport. J. Membrane Biol. 117:131-139, 1990.
2. Wang, T. and Chan, Y.L.: Cholinergic effect on rat proximal convoluted tubule. Pfug Arch. (European J. Physiol.) 415:533-539, 1990.
3. Chan, Y.L. and Wang, T.: The role of protein kinase C in mediating the stimulatory effect of angiotensin II on renal tubular transport. Cellular and Molecular Biol. of the Kidney 95:216-221, 1991.
4. Wang, T., Malnic, G., Giebisch, G. and Chan, Y.L.: Renal bicarbonate reabsorption in the rat: IV bicarbonate transport mechanisms in the early and late distal tubule. J. Clin. Invest. 91:2776-2784, 1993.
5. Jin, B. and Chan, Y.L. Dopaminergic regulation of renal tubular function: A patch clamp study. Proceeding of the International Conference on Advance Science and Technology, Vol 12, pg. 111-118, 1996.
6.Wang, T. and Chan, Y.L. Effects of prostaglandin and ang II on proximal and distal tubular bicarbonate transport. Proceeding of the International Conference on Advance Science and Technology, Vol 12, pg. 119-124, 1996.