Increased sensitivity to prostaglandin E₂ in old people

Prostaglandin E₂ acts as a feedback inhibitor on the actions of many hormones and other stimuli. For example, mitogens will cause leukocytes to produce prostaglandin E₂, and the prostaglandin E₂ inhibits the proliferative response of the leukocytes to the mitogen. We have shown that lymphocytes from healthy subjects over age 70 are much more sensitive to inhibition by prostaglandin E₂ than are lymphocytes from younger individuals. In this paper, I hypothesize that there is a generalized increase in sensitivity in all tissues in aging humans, and that this increased sensitivity accounts for many of the physiologic changes of aging.