Biochemical and histopathological changes of intra-abdominal hypertension on the kidneys: Experimental study in rats

This study aimed to evaluate the effects of experimentally induced intra-abdominal hypertension on renal functions, with the combination of biochemical and histopathological properties.

Thirty male Wistar albino rats were used in this experimental study. Rats were divided into four groups. Group 1 (control group, n=6) only received anesthesia. After the induction of anesthesia, a 20 G catheter was introduced intraperitoneally to Group 2 (sham group, n=8), Group 3 (n=8) and Group 4 (n=8). The intra-abdominal pressure was not increased in Group 2. We applied 20 mmHg intra-peritoneal pressure to Group 3 and 30 mmHg to Group 4 for 3 hours. After withdrawing 3 mL intracardiac blood from all groups, the kidneys were removed for histopathological examination. Serum urea and creatinine levels were measured in all groups.

Biochemical examination showed that blood urea and creatinine levels were statistically different among all groups (p<0.05). Serum creatinine levels in Group 3 and serum urea and creatinine levels in Group 4 were significantly increased. In the histopathological examination, the kidneys in Group 1 and Group 2 were classified as normal. In Group 3, areas with congestion were detected in the glomeruli and interstitial regions. In addition to these findings seen in Group 3, dilatation of the pelvi-caliceal structures and proximal ureters were noticed in Group 4.

The levels of serum urea and creatinine are elevated when intra-abdominal pressure is increased due to kidney damage. Foci of hemorrhage in the interstitial area, dilatations in the proximal ureter, renal pelvis, and lymphatics were the pathologic findings seen in the kidneys under such circumstances.