ORAL-ADMINISTRATION OF PUTRESCINE INHIBITS CRYPTOSPORIDIUM-PARVUM INFECTION OF NEONATAL C57BL-6 MICE AND IS INDEPENDENT OF NITRIC-OXIDE SYNTHESIS

We examined the efficacy of oral administration of putrescine (a bypro duct of arginine metabolism) in the prevention of Cryptosporidium parv um infection of neonatal C57BL-6 mice. Mice were challenged with the p arasite at 7 days of age. Mice receiving putrescine from 3 through 10 days of age had a delayed pattern of infection as compared with contro l mice. Mice receiving putrescine from 3 through 21 days of age did no t become infected, whereas control mice were heavily infected. We also rested the hypothesis that putrescine inhibited C. parvum infection b y enhancing nitric oxide (NO) production, Mice receiving the NO inhibi tor N omega-L-arginine methyl ester (L-NAME) parenterally and putresci ne orally did not become infected. Thus, it appears that putrescine in hibits C. parvum infection in an NO-independent manner.