Effects of arginine and ornithine supplementation to a high‐protein diet on selected cellular immune variables in adult cats

Abstract

Background Dietary protein and amino acid intake and composition can modulate immune function. Objectives To evaluate the effects of high‐protein intake and arginine and ornithine supplementation on feline immune cells. Animals Ten healthy cats. Methods Experimental study. Cats received a high‐protein basal diet as a single daily meal. A crossover design was applied with treatments being basal diet (w/o); basal diet with arginine supplementation (+50, 75, 100% compared to the arginine provision by the basal diet; Arg 1‐3); and basal diet with ornithine supplementation (+100, 150, 200% compared to the arginine provision by the basal diet; Orn 1‐3). Blood samples were collected at the end of each 11‐day treatment period. Results Mitogen‐stimulated proliferative activity of blood leukocytes revealed a quadratic effect for the dietary supplementation of arginine (P = .02) and ornithine (P = .03) (means for ConA‐stimulation: w/o = 6.96; Arg 1 = 9.31; Arg 2 = 11.4; Arg 3 = 8.04; Orn 1 = 15.4; Orn 2 = 9.43; Orn 3 = 9.28; pooled SEM: 0.96). The number (% gated) of phagocytic granulocytes linearly decreased with increasing dietary concentrations of arginine (P = .05) and ornithine (P = .03) (means: w/o = 95.5; Arg 1 = 93.0; Arg 2 = 92.5; Arg 3 = 92.6; Orn 1 = 92.6; Orn 2 = 92.6; Orn 3 = 91.5; pooled SEM = 0.44). Conclusions and Clinical Importance This study could demonstrate immunomodulating properties of dietary arginine and ornithine in cats.

Amino acid nutrition and metabolism in domestic cats and dogs

“…AAs are essential for immune responses in all animals (including cats and dogs) through a plethora of mechanisms, such as the syntheses of proteins (including antibodies and cytokines) and glutathione (a potent anti-oxidative tripeptide consisting of glycine, cysteine, and glutamate), as well as the killing of pathogens via production of NO from arginine and of chlorotaurine and bromotaurine from taurine [ 61 ]. Supplementing arginine to a low-protein (23% CP) [ 146 ] or high-protein (60% CP) [ 147 ] diet has beneficial immunomodulating effects in cats. In addition, intravenous administration of alanyl-glutamine to dogs undergoing a treatment with methylprednisolone sodium succinate enhanced phagocytic capacity and respiratory burst activity of leukocytes [ 148 ].…”