medium chain triglyceride oil, corn oil, soy lecithin, vitamins, minerals, fructooligosaccharides, lactose, gluten, and growth factor free) consumed by the mice was similar throughout the week (15 ml/day). Body weight did not differ between the Perative fed and chow fed groups. Northern blot analysis 6 of total RNA extracted from the jejunum and ileum, using an oligo probe specific to cryptdin 1, cryptdin 2, and cryptdin 3 (.93% nucleotide identity), or cryptdin 4, revealed that levels of cryptdins 1-3 ( fig 1A) and cryptdin 4 ( fig 1B) increased by 1.6-fold (Student's t test, p,0.05).To further study the direct effect of Perative on Paneth cells, we isolated primary Paneth cells7 from mouse jejunum and tested the effect of different concentrations of Perative (0.0025%, 0.01%, 0.025%), isoleucine, and arginine (25, 100, 250 mg/ml) on cryptdin expression by real time polymerase chain reaction.6 Whereas different concentrations of arginine and isoleucine did not stimulate cryptdin expression (Student's t test, p. 0.05), 0.025% Perative increased significantly expression of cryptdins 1-3 (Student's t test, p = 0.003) (fig 1 C) and cryptdin 4 (Student's t test, p,0.0001) ( fig 1C). The ability of similar concentrations of isoleucine and arginine to induce human b-defensin in HCT-116 cells 8 stems, most probably, from the difference in the mechanism regulating expression of cryptdins (adefensins) versus b-defensins. Different control of a-and b-defensin expression is further reiterated by the fact that spleens challenged with Listeria monocytogenes, lungs infected with influenza A, and kidneys challenged with Candida albicans, all b-defensin expressing tissues, revealed no differences in the cure rate when mice were fed Perative or other immune enhancing formulas.
