Modulation of neuropeptide Y and norepinephrine on several leucocyte functions in adult, old and very old mice.

The age-related changes in the communication between the nervous and the immune system have been scarcely investigated, especially in very aged subjects. The present work deals with the in vitro effects of norepinephrine and neuropeptide Y, separately and jointly, on functions such as lymphoproliferation, NK activity, and IL-2 and TNF-alpha release of peritoneal leucocytes from adult (24+/-2 weeks), old (72+/-2 weeks) and very old (128+/-2 weeks) mice. The old mice showed a decrease in proliferation, NK activity and IL-2 release, and an increase in TNF-alpha, whereas in the very old mice these functions were more similar to those of the adults. The effects of neurotransmitters on these functions were different depending on the age of the animals.