Effects of lactulose on blood ammonia levels in beagles with end-to-side portacaval shunt.

Publisher Website
Google Scholar
Abstract
The effects of lactulose on blood ammonia and fecal pH in beagles with an end-to-side portacaval shunt were investigated. Concentrations of blood ammonia before and two weeks after the operation were 4.65 .+-. 0.34 .mu.g/ml (N = 12) and 8.66 .+-. 0.60 .mu.g/ml (n = 6), respectively (P < 0.01), while there was no significant difference in fecal pH values before and after the operation. The blood ammonia concentrations in the control and lactulose-treated (2.1 g/kg, p.o.) groups after administration of meat were 12.65 .+-. 1.64 .mu.g/ml (N = 8) and 8.45 .+-. 0.90 .mu.g/ml (N = 8), respectively (P < 0.05). The fecal pH values in the control and lactulose-treated (2.1 g/kg, p.o.) beagles were 6.24 .+-. 0.09 (N = 8) and 5.58 .+-. 0.08 (n = 8), respectively (P < 0.01). The lowering effect of lactulose on the blood ammonia levels could not be ascribed to its laxative action alone, because the oral administration of the lactulose at doses less than 2.1 g/kg induced no fluid evacuation. The present studies in the beagle suggest that the action of lactulose produce a lowering of fecal pH, causing an increase in the concentration of less absorbable ammonium ions and a decrease in the production of toxic nitrogenous compounds such as ammonia, resulting in a reduction in blood ammonia levels.