Thymopoietin and thymopentin enhance the levels of ACTH, beta-endorphin and beta-lipotropin from rat pituitary cells in vitro

Thymopoietin and thymopentin are well characterized polypeptides influencing
immunoregulation by several mechanisms. Proposed as a therapy in diseases with
major immune abnormalities such as rheumatoid arthritis, thymopentin improved
within 2 weeks some clinical parameters as pain and joint swelling. The
hypothesis that this spectacular effect could be mediated through interactions
with anti-inflammatory (ACTH) and pain relieving (beta-endorphin) hormones
producing cells was tested on the rat isolated pituitary cell model. Thymopentin
and thymopoietin can enhance in vitro the levels of ACTH, beta-endorphin and
beta-lipotropin in a time- and dose-dependent fashion for physiological
concentrations ranging from 10(-12) to 10(-8) mol/l. The action on pituitary
cells was restricted to those molecules as no changes occurred in LH, FSH, GH,
TSH and PRL levels, after otherwise identical experimental conditions.