Age-Related Decline in Response to Phytohemagglutinin and Pokeweed Mitogen by Spleen Cells from Hamsters and a Long-Lived Mouse Strain

Abstract

The splenic lymphocytes of young, middle-aged, and moderately old (80-94 weeks) MHA hamsters showed a moderate, age-related decline in response to stimulation by phytohemagglutinin and a lesser decline for pokeweed mitogen, as measured by tritiated thymidine uptake in vitro. In longlived (C57BL/6J × 129) F₁-hybrid mice a marked decline in response to both mitogens was found for middle-aged and very old mice. in mice at least the response of spleen cells to PHA is a measure of thymus-dependent (T-cell) lymphoid function, whereas the response to pokeweed measures both T-cell and B-cell functions. The results indicate a marked falloff in T-cell function with age, and suggest that B-cell function may also decline to some extent.