The experiments described in this proposal are directed at identifying the cellular transport processes involved in intracellular pH (pHi) regulation in the principal and intercalated cells of the rabbit cortical and outer medullary collecting tubule and the S1, S2 and S3 segments of the proximal tubule of the rabbit kidney. I will use the isolated perfused tubule preparation, a recently developed videomicrofluorometer and the pH probes 1,4 DHPN or BCECF to measure pHi in individual cells. First, the transport processes involved in pHi regulation will be determined. Second, the coupling of energy metabolism to work output, and the substrate specificity of this process will be assessed by measuring the fluorescence of NADH in individual cells. The results will increase the understanding of bicarbonate transport in the proximal tubule and the collecting tubule which will be important in understanding various pathophysiologic states of acid-base homeostasis which affect the nephron.

Project Start
1987-08-15
Project End
1991-12-31
Budget Start
1990-09-10
Budget End
1991-12-31
Support Year
4
Fiscal Year
1990
Total Cost
Indirect Cost
Name
University of California Los Angeles
Department
Type
Schools of Medicine
DUNS #
119132785
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Mackovic-Basic, M; Fan, R; Kurtz, I (1992) Denervation inhibits early increase in Na(+)-H+ exchange after uninephrectomy but does not suppress hypertrophy. Am J Physiol 263:F328-34
Mackovic-Basic, M; Fine, L G; Norman, J T et al. (1992) Stimulation of Na+/H+ exchange is not required for induction of hypertrophy of renal cells in vitro. J Am Soc Nephrol 3:1124-30
Kurtz, I (1991) Role of ammonia in the induction of renal hypertrophy. Am J Kidney Dis 17:650-3
Parton, R G; Dotti, C G; Bacallao, R et al. (1991) pH-induced microtubule-dependent redistribution of late endosomes in neuronal and epithelial cells. J Cell Biol 113:261-74
Wang, X; Kurtz, I (1990) H+/base transport in principal cells characterized by confocal fluorescence imaging. Am J Physiol 259:C365-73
Golchini, K; Mackovic-Basic, M; Gharib, S A et al. (1990) Synthesis and characterization of a new fluorescent probe for measuring potassium. Am J Physiol 258:F438-43
Mackovic-Basic, M; Kurtz, I (1990) H+/base transport in the proximal straight tubule and thin descending limb of Henle. Semin Nephrol 10:122-31
Golchini, K; Norman, J; Bohman, R et al. (1989) Induction of hypertrophy in cultured proximal tubule cells by extracellular NH4Cl. J Clin Invest 84:1767-79
Ferdows, M; Golchini, K; Adler, S G et al. (1989) Cl-/base exchange in rat mesangial cells: regulation of intracellular pH. Kidney Int 35:783-9
Kurtz, I (1988) Apical and basolateral Na+/H+ exchange in the rabbit outer medullary thin descending limb of Henle: role in intracellular pH regulation. J Membr Biol 106:253-60