Effects of the antisecretory factor in pigs

Area of Science:

• Gastroenterology
• Immunology
• Veterinary Medicine

Background:

• Enterotoxins from Escherichia coli (heat-labile enterotoxin, LT) and Vibrio cholerae (cholera toxin, CT) cause significant jejunal secretion in pigs.
• Antisecretory factor (ASF) is a substance with potential to counteract enterotoxin-induced intestinal fluid loss.

Purpose of the Study:

• To investigate the efficacy of antisecretory factor (ASF) in mitigating experimental porcine enterotoxin-induced jejunal secretion.
• To determine the dose-dependency and administration route of ASF.
• To explore the effect of ASF on ionic concentrations in secreted fluid and its presence in pig pituitary glands.

Main Methods:

• Ligated intestinal loops in pigs were challenged with LT and CT.
• ASF was administered intravenously or intra-intestinally prior to toxin challenge.
• ASF's effect on Na+, K+, and Cl- concentrations in secreted fluid was analyzed.
• Pituitary ASF content was measured in pigs of different ages and after vaccination.

Main Results:

• Less than 10 units of ASF inhibited LT-induced secretion, while CT-induced secretion required over 10 units.
• ASF was effective only when administered before toxin challenge.
• ASF did not alter the ionic concentrations (Na+, K+, Cl-) of the secreted fluid.
• Pituitary ASF levels increased with age and significantly after cholera toxin vaccination in young pigs.

Conclusions:

• ASF demonstrates significant antisecretory effects against LT and CT in pigs.
• ASF's efficacy is dependent on timing and administration route, and it does not affect ion transport directly.
• Age and vaccination status influence endogenous ASF levels, suggesting a role in immune response.