Incorporation of hormones and hormone-like materials by rat lymphocytes at different ontogenetic stages.

The quantities of hormones and hormone-like materials (histamine, dopamine, epinephrine, diiodotyrosine and corticosterone, in the following collectively: hormones) incorporated by the lymphocytes of neonatal rats were several orders greater than those taken up by the lymphocytes of adult rats. Uptake tended to decrease by one week of age, but it was still 2-3 times greater than in adulthood. It fell to a minimum at two weeks to one month of age, then it increased slightly by 2 or 6-8 months of age.