Scintigraphic Evaluation of the Impact of Pneumoperitoneum on Renal Blood Flow: A Rabbit Model.

Background: Increased intra-abdominal pressure resulting from pneumoperitoneum can cause renal physiological changes, such as oliguria and anuria, in mammals. Although videolaparoscopic operations are common, the occurrence of renal lesions due to these procedures has not been precisely documented in the literature. The aim of this study was to evaluate the impact of pneumoperitoneum on renal blood flow using renal scintigraphy in a rabbit model. Methods: Six New Zealand male rabbits weighing 3 kg, previously anesthetized, were mechanically ventilated and underwent pneumoperitoneum. Each animal served as its own control and was analyzed in two different moments: [99mTc] diethylenetriaminepentaacetic acid (DTPA) renal blood flow evaluation in baseline conditions (T0) and 30 minutes after installation of 15 mmHg-pneumoperitoneum (T1). The animals were monitored throughout the study by capnography, oximetry, and arterial pressure median, and were euthanized at the end of the experiment. Results: The quantitative analysis of the scintigraphic images of renal uptake of the radiopharmaceutical evidence reduced renal arterial blood flow during pneumoperitoneum. Compared with baseline conditions, all animals presented a reduction of renal blood flow varying from 16% to 82%, with mean [±standard deviation] of 53% [±24%]. Conclusions: Pneumoperitoneum induces a significant reduction of the renal blood flow, as determined in this experimental method in rabbits and dynamic renal scintigraphy with [99mTc] DTPA is an adequate method to investigate this event in the experimental setting.

Retinyl-palmitate reduces liver fibrosis induced by biliary obstruction in rats.

BACKGROUND/AIMS: The administration of retinoid in various experimental models of induced hepatic cirrhosis has shown antifibrogenic effects. The purpose of this study was to verify if vitamin A could interfere in hepatic fibrosis induced by biliary obstruction. METHODOLOGY: Male Wistar rats that underwent biliary obstruction were treated 2 weeks before the surgery with a dose of 50 x 10(3) IU retinyl-palmitate, twice a week, and then given the dosage for 5 weeks following surgery. They were then sacrificed and hepatic fragments removed to find out the biochemical dosage of hydroxyproline and the stereologic volume of collagen. Blood samples were also collected to find the biochemical dosage. RESULTS: The rats that underwent biliary obstruction and received vitamin A presented lower levels of hepatic hydroxyproline (p < 0.001) as well as a lower percentage of collagen tissue than the untreated control rats, but they presented higher AST and ALT serum levels (p < 0.05, p < 0.05). CONCLUSIONS: Under the above experimental conditions, the administration of vitamin A significantly reduced hepatic fibrosis.