Cirrhosis in rats does not resolve in the long-term after induction by thioacetamide model

Introductions: Hepatic cirrhosis is a final common pathway of all chronic liver diseases, characterized by deposit of fibrillar collagen and liver failure. Materials and Methods: In this experiment, hepatic cirrhosis was induced in 15 female Wistar rats by a 14-week period, with thioacetamide solution in a 200 mg/kg dosage, via intraperitoneal. Animals were submitted to liver biopsy, and euthanized after a 80-day post-induction period. Serum biochemical analysis was performed, in addition to histopathology by H.E., Picrosirius, Alcian Blue and P.A.S. stainings, following analysis of histological activity index and staging of fibrosis. Morphometric analysis of collagen on Picrosirius slides was also performed. Results: Mortality during experimental period was low (13.33%), and after 80-day period, liver function improved, cellular changes did not altered, and deposition of acidic mucopolysaccharides and glycogen were increased. Liver histological activity did not change significantly (7.25 ± 1.30 to 6.41 ± 1.32), but staging of fibrosis was altered (3.91 ± 0.76 to 4.70 ± 1.11). Interlobular collagen showed a significant decrease (5.14 ± 2.00 to 4.00 ± 1.20), while intralobular collagen was increased (0.23 ± 0.06 to 0.36 ± 0.08). Conclusions: These findings characterize thioacetamide as a safe experimental model for induction cirrhosis, which may be used for future therapy studies.(AU)

Effects of aflatoxins on performance and exocrine pancreas of broiler chickens.

The aim of this research was to evaluate, on a weekly basis, the effects of aflatoxins on the activity of digestive enzymes (alpha-amylase, lipase, and trypsin) in the pancreas as well as on the performance and histology of pancreas in broiler chickens over the course of 42 days. One thousand and eighty 1-day-old male Cobb broilers were divided into four treatments with 18 replicates and 15 birds per replicate (i.e., 270 broilers per treatment). Treatments were established according to the amount of aflatoxins added to the diet, as follows: T1 = 0 mg of aflatoxins per kilogram of feed (mg/kg); T2 = 0.7 mg/kg; T3 = 1.7 mg/kg; and T4 = 2.8 mg/kg. Pancreas sample collection was performed from one bird out of each replicate at 7, 14, 21, 28, 35, and 42 days of experiment, which yielded a total of 18 samples per treatment on each collection. Each sample was homogenized in distilled water, frozen in liquid nitrogen, lyophilized, and stored at -20 C until analysis. Performance parameters (body weight, feed consumption, and feed conversion rate) were measured at 21, 35, and 42 days of experiment. At the end of the experiment (42 days), six birds from each treatment were randomly chosen for histologic evaluation of the pancreas. The presence of aflatoxins in the diet induced a negative effect on all performance parameters. The pancreatic activity of lipase and alpha-amylase were significantly increased in treatments T3 and T4, while the specific activity of trypsin was only affected during treatment T4. In addition, several histologic changes were observed in the pancreas of birds receiving aflatoxin-contaminated feed. Aflatoxins present in the feed determined an increase in the activity of pancreatic enzymes in broilers, affecting the digestibility of the diet, thereby leading to losses in performance and productivity.