Effects of early destruction of the mouse arcuate nucleus by monosodium glutamate on age-dependent natural killer activity.

The present study has examined the effect on age-dependent natural killer (NK) cell cytotoxic (NKCC) activity after the destruction of the arcuate nucleus (AR) of the hypothalamus in newborn mice with the neurotoxin monosodium glutamate (MSG). The NKCC activity was determined at different ages from the 18th day to the 54th week. This treatment resulted in depressed NKCC activity and in disappearance of its age-dependent pattern. A high correlation between NKCC depression and decreased numbers of large granular lymphocytes was also noted in the MSG-treated mice. The conclusion is that normal development of NKCC activity requires the maturation of AR functions.