Summary
The technique and evaluation of the split oil drop method of Gertz was reexamined in rats with a view to defining the correct dimension in which the results should be expressed so that the point of reference for reabsorptive capacity thus obtained be uninfluenced by the geometry of the tubule.
-
1.
It was found that one tubular diameter had to be added to each length between the tops of the approaching menisci to produce a truly linear relationship between these lengths and time. This correction improved the coefficient of variation (reproducibility) of the reabsorptive half time (t 1/2) and eliminated the correlation between the length of the split column andt 1/2.
-
2.
Furthermore a significant correlation was found between internal tubular radius and correctedt 1/2's in a group of tubules with naturally varying diameters, indicating constancy of reabsorptive capacity per unit surface area.
-
3.
The reproducibility of reabsorptive capacity per unit surface area,J v (a) thus obtained (coefficient of variation of 17%,n=44) was found to compare very favourably with other micropuncture techniques measuring the same parameter. The reproducibility of this parameter when expressed per unit tubular length,J v (l) was 23% (n=44). The accuracy of the method as measured by duplicate determinations was at 10% even better (n=38). From these considerations it was concluded that reabsorptive capacity of tubules should be expressed per unit area when comparisons between different tubules are to be made, and per unit length when comparisons of two or more determinations in the same tubule are to be compared.
-
4.
The small difference inJ v found between measurements made with the Gertz method and microperfusion methods using TF/P inulin ratios was not due to the oil used nor was it due to a possible mechanical damage by the relatively large size of the double barrelled glass capillary usually employed in the Gertz method.
Similar content being viewed by others
References
Bank, N., Koch, K. M., Aynedjian, H. S., Avas, M.: J. clin. Invest.48, 271 (1969).
Gertz, K. H.: Pflügers Arch. ges. Physiol.276, 336 (1963).
—, Mangos, J. A., Braun, G., Pagel, H. D.: Pflügers Arch. ges. Physiol.285, 360 (1965).
Györy, A. Z.: Pflügers Arch.319, R 77 (1970).
Hayslett, J. P., Kashgarian, M., Epstein, F. H.: J. clin. Invest.47, 774 (1968).
Morel, F., Murayama, Y.: Pflügers Arch.320, 1 (1970).
Morgan, T., Berliner, R. W.: Amer. J. Physiol.217, 992 (1969).
Nakajima, K., Clapp, J. R., Robinson, R. R.: Amer. J. Physiol.219, 345 (1970).
Radtke, H. W., Rumrich, G., Klöss, S., Ullrich, K. J.: Pflügers Arch.319, R 78 (1970).
Schnermann, J., Levine, D. Z., Horster, M.: Pflügers Arch.308, 149 (1969).
Snedecor, G. W., Cochran, W. G.: Statistical methods. 6th Edition. Iowa: Iowa State University Press 1967.
Steinhausen, M.: Pflügers Arch. ges. Physiol.298, 105 (1967).
—, Iravani, F., Schubert, G. E., Taugner, R.: Virchows Arch. path. Anat.336, 503 (1963).
Ullrich, K. J.: Permeability characteristics of the mammalian nephron. In: Handbook of physiology. Executive Editor: Stephan R. Geiger. Baltimore: The Williams and Wilkins Company (in press).
—, Frömter, E., Baumann, K.: Micropuncture and microanalysis in kidney physiology. In: Laboratory techniques in membrane biophysics. Edited by H. Passow and R. Stämpfli. Berlin-Heidelberg-New York: Springer 1969.
Wiederholt, M., Langer, K. H., Thoenes, W., Hierholzer, K.: Pflügers Arch.302, 166 (1968).
Wright, F. S., Howards, S. S., Knox, F. G., Berliner, R. W.: Amer. J. Physiol.217, 199 (1969).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Györy, A.Z. Reexamination of the split oil droplet method as applied to kidney tubules. Pflugers Arch. 324, 328–343 (1971). https://doi.org/10.1007/BF00592461
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00592461