AGE-ASSOCIATED CHANGES IN TUMOR-NECROSIS-FACTOR-ALPHA RECEPTOR ON PERIPHERAL-BLOOD MONOCYTES AND BONE-MARROW MACROPHAGES FROM ICR MICE AND WISTAR RATS

We examined the age-associated changes in tumor necrosis factor alpha (TNFalpha) receptor on peripheral blood monocytes and bone marrow macr ophages obtained from slc:Wistar rats and slc:ICR mice. The TNFalpha r eceptor on monocytes and macrophages in both rats and mice showed high and low affinity sites. The Kd values of those sites gradually increa sed with age in both types of cells from both species. Binding capacit ies (receptor number) were low in 52-week-old animals. These results s uggest that the TNFalpha receptor on monocytes and macrophages of thes e species might decrease with age in both quality and quantity.