Proximal tubule morphology in rats with renal congestion: a study involving the in vivo cryotechnique

Abstract

The present study aimed to examine the changes induced in proximal tubules by renal congestion using the in vivo cryotechnique (IVCT). Twelve male Wistar rats were divided into four equal groups: group 1 (the control); groups 2 and 3, which were subjected to 2 and 5 min of congestion, respectively; and group 4, which was subjected to 5 min of congestion followed by 10 min of recirculation. Under anesthesia, renal congestion was induced in the bilateral kidneys by ligating the inferior vena cava just above the branching renal veins. The left kidneys, which were subjected to the IVCT, were then compared with the right kidneys, which underwent a conventional fixation method. Among the left kidneys, the proximal tubules in group 1 consisted of cuboidal cells and had open lumina. In the congestive groups, the diameters of the proximal tubules were increased, and their lumina were obstructed by swollen cells and ischemia-associated cell debris. In group 4, the proximal tubules were still dilated, as seen in the congestive groups; however, the swollen cells had recovered their cuboidal form, and the cell debris had disappeared from the tubules' lumina. The present study demonstrated the in vivo morphology of proximal tubules in living rats subjected to congestion, which was unclear using conventional fixation methods.

Effects of Anabolic Steroids on the Histological Structure of Renal Cortex of Adult Male Albino Rats and the Possible Protective Role of Taurine

“…Moreover, the study of Zeier M et al (1998) documented that testosterone amplifies the compensatory growth of residual nephrons and such nephron hypertrophy may set the stage for accelerated progression of renal disease [35] . However, AAS induced PCT increased diameter and luminal debris detected in the present study could also be attributed to the observed congestion where Hemmi et al, (2015) stated that renal congestion was accompanied by an increase in diameter of PCT and obstruction of their lumina by swollen cells and ischemia-associated cell debris [36] .…”

The Convoluted Tubules of the Nephron Must Be Considered Elliptical, and Not Circular, in Stereological Studies of the Kidney

“…Several authors considered that the tubules have a circular shape and therefore measured only one diameter [3][4][5][6][7][8][9][10]. However, our results showed that the convoluted tubules of the kidney are elliptical in shape; we measured a short diameter (the short axis of the ellipse) and a long diameter (the long axis of the ellipse) which differed significantly from each other (Table 1; Fig.…”

“…However, there is no consensus in the literature on how tubular diameter (or diameters) should be evaluated. Several authors measure only one diameter, as if the tubules were circular [3][4][5][6][7][8][9][10]. On the contrary, other authors consider that the tubules have an elliptical shape and report the short diameter (minimum, proximal), sometimes along with the large diameter (maximum, distal) [11][12][13][14][15][16][17][18][19][20].…”

Tubular and Glomerular Size by Cortex Depth as Predictor of Progressive CKD after Radical Nephrectomy for Tumor

“…It has been well-established in rodent models of early CKD that in addition to glomerular hypertrophy, there is tubular hypertrophy. 14 Rodent models have primarily studied proximal tubules, [14][15][16][17][18] although a few have also evaluated distal tubules. 19,20 A study in human kidneys found that obese patients had a 54% larger cross-sectional area of proximal tubules than nonobese patients.…”