Peritoneal concentrations of transforming growth factor beta in horses with colic

Reasons for performing the study: In man, peritoneal transforming growth factor beta (TGF‐β) is associated with peritoneal diseases and subsequent adhesion formation. No studies on plasma and peritoneal TGF‐β concentrations in horses with colic are available. Objectives: 1) To determine both plasma and peritoneal TGF‐β₁ and TGF‐β₃ concentrations in horses with different types of colic (not previously subjected to abdominal surgery); 2) to compare these concentrations according to the type of peritoneal fluid (transudate, modified transudate and exudate); and 3) to compare and correlate plasma and peritoneal concentrations of TGF‐β₁ and TGF‐β₃ and the types of peritoneal fluid according to the colic group and outcome. Methods: Peritoneal fluid and plasma samples from 78 horses with colic and 8 healthy horses were obtained. Patients were classified according to diagnosis (obstructions, enteritis, ischaemic disorders and peritonitis), peritoneal fluid analysis (transudate, modified transudate and exudate), and outcome (survivors and nonsurvivors). Plasma and peritoneal TGF‐β₁ and TGF‐β₃ concentrations were determined by ELISA. Data were analysed by parametric and nonparametric tests. P≤0.05 was considered as statistically significant. Results: Concentrations of peritoneal fluid TGF‐β₁ were significantly (P = 0.01) higher in horses with peritonitis in comparison with all other colic groups and controls. Horses with ischaemic lesions had significantly (P = 0.01) higher concentrations of peritoneal TGF‐β₁ in comparison with controls and the group of horses with obstructions. Peritoneal TGF‐β₁ concentration also was significantly (P = 0.01) higher in exudates in comparison with transudates. Peritoneal TGF‐β₁ and TGF‐β₃ concentrations and plasma TGF‐β₁ concentration were significantly increased in nonsurvivors compared to survivors (P = 0.001, P = 0.004 and P = 0.05, respectively). Conclusions: Peritoneal TGF‐β₁ concentration was higher in horses with severe gastrointestinal diseases (ischaemic intestinal lesions and peritonitis), in horses with an altered peritoneal fluid (exudate), and in nonsurvivors. Potential relevance: Peritoneal TGF‐β concentration increases in horses with severe gastrointestinal disease as an anti‐inflammatory response.