Early segmental changes in ischemic acute tubular necrosis of the rat kidney.

TY - JOUR

T1 - Early segmental changes in ischemic acute tubular necrosis of the rat kidney.

AU - Faarup, Poul

AU - Nørgaard, Tove

AU - Hegedüs, Viktor

AU - Holstein-Rathlou, N.-H.

N1 - Keywords: Animals; Ischemia; Kidney; Kidney Cortex; Kidney Tubular Necrosis, Acute; Kidney Tubules, Proximal; Male; Rats; Rats, Wistar

PY - 2004

Y1 - 2004

N2 - The background and mechanisms of ischemic acute tubular necrosis are still essentially unclarified. Therefore a quantitative morphological technique was applied for evaluation of the early structural changes in different fractions of the proximal convoluted tubule in the rat renal cortex. In male pentothal-anesthetized Wistar rats (body weight 200-250 g) ischemia of the right kidney was obtained by clamping (clamp diameter 0.15 mm) the ipsilateral renal artery for varying periods of time (10 min to 6 h) followed by removal and instant freezing of the kidney in isopentane at -165 degrees C and subsequent freeze-substitution in alcohol. The microscopic slides from the kidneys were silver methenamine-PAS stained. In the segments of the proximal convoluted tubules of the nephrons, presence of nuclear pyknosis, places of denuded basement membranes and presence of exfoliated tubular cells were counted. The results were statistically treated for comparison between the extent of damage in the initial postglomerular fraction and the later tubular loops. All three parameters showed a systematic, statistically significant increased number of lesions in the initial fraction of the proximal convoluted tubule versus the subsequent loops. The distribution of the structural lesions is in accordance with the previously reported presence of a tubulo-capillary counter-current flow in the proximal convoluted tubule and, when related to the highly variable oxygen tension in the normal renal cortex of the rat, indicates that the peculiar location of the early lesions might well be determined by these functional conditions.

AB - The background and mechanisms of ischemic acute tubular necrosis are still essentially unclarified. Therefore a quantitative morphological technique was applied for evaluation of the early structural changes in different fractions of the proximal convoluted tubule in the rat renal cortex. In male pentothal-anesthetized Wistar rats (body weight 200-250 g) ischemia of the right kidney was obtained by clamping (clamp diameter 0.15 mm) the ipsilateral renal artery for varying periods of time (10 min to 6 h) followed by removal and instant freezing of the kidney in isopentane at -165 degrees C and subsequent freeze-substitution in alcohol. The microscopic slides from the kidneys were silver methenamine-PAS stained. In the segments of the proximal convoluted tubules of the nephrons, presence of nuclear pyknosis, places of denuded basement membranes and presence of exfoliated tubular cells were counted. The results were statistically treated for comparison between the extent of damage in the initial postglomerular fraction and the later tubular loops. All three parameters showed a systematic, statistically significant increased number of lesions in the initial fraction of the proximal convoluted tubule versus the subsequent loops. The distribution of the structural lesions is in accordance with the previously reported presence of a tubulo-capillary counter-current flow in the proximal convoluted tubule and, when related to the highly variable oxygen tension in the normal renal cortex of the rat, indicates that the peculiar location of the early lesions might well be determined by these functional conditions.

U2 - 10.1111/j.1600-0463.2004.apm1120305.x

DO - 10.1111/j.1600-0463.2004.apm1120305.x

M3 - Journal article

C2 - 15153161

SN - 0903-465X

VL - 112

SP - 192

EP - 200

JO - APMIS. Supplementum

JF - APMIS. Supplementum

IS - 3

ER -