Abstract
A new ophidian kidney preparation is described which allows the measurement of glomerular arteriolar diameters, glomerular blood flow, and glomerular capillary pressure in real time. Intravital epifluorescence video microscopy is utilized to observe and record blood flow in the renal microcirculation in the garter snake, Thamnophis sirtalis. Carotid, renal artery and glomerular capillary pressures are recorded digitally on the video recording simultaneously with the images with an eight-channel video data recorder, maintaining synchrony of all data. On the video replay, glomerular arteriolar diameters are measured with a video micrometer and RBC velocity determined with the video dual-slit method. Blood flow is continuously calculated from the diameter and RBC velocity measurements. The continuous and simultaneous measurements of the pressure gradient across the afferent limb of the glomerular circulation, the renal artery to glomerular capillary pressure drop, and the rate of glomerular blood flow allow the continuous calculation of afferent glomerular arteriolar resistance in real time. This is the first demonstration of these capabilities in a vertebrate kidney.
References
Baker M, Wayland H (1974) On-line volume flow rate and velocity profile measurement for blood in microvessels. Microvas Res 7:131–143
Blantz RC, Tucker BJ (1978) Measurements of glomerular dynamics. In: Martinez-Maldonado M (ed) Methods in Pharmacology vol 4B Plenum, New York, p141
Brenner BM, Troy JL, Daugharty TM (1971) The dynamics of glomerular ultrafiltration in the rat. J Clin Invest 50:1776–1780
Casellas D, Navar LG (1984) In vitro perfusion of juxtamedullary nephrons in rats. Am J Physiol 246:F349-F358
Intaglietta M, Silverman NR, Tompkins WR (1975) Capillary flow velocity measurements in vivo and in situ by television methods. Microvas Res 10:165–179
Klitzman B, Myers J, Watts RP, Johnson PC (1982) Measurement of microvascular hematocrit and red cell velocity using stroboscopic epifluorescence microscopy. Fed Proc 41:1759
Lipowsky HH, Zweifach BW (1978) Application of the “two-slit” photometric technique to the measurement of microvascular volumetric flow rates. Microvas Res 15:93–101
Steinhausen M, Snoei H, Parekh N, Baker R, Johnson PC (1983) Hydronephrosis: a new method to visualize vas afferens and vas efferens in vivo as well as the glomerular network. Kidney Int 23:794–806
Steinhausen M, Zimmerhackl B, Thederan H, Dussel R, Parekh N, Eblinger H-U, von Hagens G, Komitowski D, Dallenbach FD (1981) Intraglomerular microcirculation: measurements of single glomerular loop flow in rats. Kidney Int 20:230–239
Wayland H, Johnson PC (1967) Erythrocyte velocity measurement in microvessels by a two-slit photometric method. JAppl Physiol 22:333–337
Wiederhelm CA, Woodbury JW, Kirk S, Rushmer RF (1964) Pulsatile pressures in the microcirculation of frog's mesentery. Am J Physiol 207:173–176
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Yokota, S.D. Ophidian kidney preparation for the measurement of glomerular dynamics in real-time. Pflügers Arch 415, 501–503 (1990). https://doi.org/10.1007/BF00373632
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00373632