Outflux of 45Calcium Along the Rat Nephron
From previous micropuncture data (1,4–6,9–15,17,19) it was postulated that calcium is reabsorbed in the proximal tubule and in addition in the distal tubule and/or collecting duct. This was concluded by comparing the amount of calcium present at the distal puncture site and that in final urine. Although this discrepancy between distal and urinary calcium load as detected by free flow micropuncture and clearance techniques might reflect distal reabsorption of calcium, it is no direct prove for that. A similar result might be obtained if there was nephron heterogeneity in regard to calcium reabsorption with the implication that deeper nephrons reabsorb calcium more avidly than superficial ones.
KeywordsProximal Tubule Distal Tubule Distal Convoluted Tubule Nephron Segment Calcium Reabsorption
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- 3.Constanzo,L.S., Windhager, E.E.: Characteristics of calcium transport in the distal convoluted tubule. Kidney Int. 10, 489 (1976)Google Scholar
- 7.Greger, R., Lang, F. and Oberleithner, H.: Distal site of calcium reabsorption in the rat kidney. Pflügers Arch. submitted.Google Scholar
- 9.Kövér, G.: Effect of hypercalcaemia on tubular calcium and phosphate transport. Acta Physiol. Acad. Sci, Hung. 45, 95107 (1974)Google Scholar
- 10.Kuntzinger, H., Amiel, C., Roinel, N., Morel, F.: Effects of parathyroidectomy and cyclic AMP on renal transport of phosphate, calcium, and magnesium. Am.J.Physiol. 227, 905–911 (1974)Google Scholar
- 11.Lassiter, W.E., Gottschalk, C.W., Mylle, M.: Micropuncture study of renal tubular reabsorption of calcium in normal rodents. Am.J.Physiol. 204, 771–775 (1963)Google Scholar
- 18.Ullrich, K.J., Capasso, G., Rumrich, G., Klöss, S.: Effect of parathyroid hormone on the active Ca2+-reabsorption in the proximal convolution of the rat kidney. Pflügers Arch. 359, R 118 (1975)Google Scholar