Abstract
Bradykinin, as well as histamine which has been considered as one of the chemical mediators in immediate type allergic reaction, increases cyclic adenosine 3′ 5′-monophosphate (cAMP) of murine lymphocytes, especially T lymphocytes and it is also shown that both bradykinin and histamine suppress T cell mitogens (PHA-P, Con A) - induced proliferation of murine splenic lymphocytes.
These results suggest that bradykinin as well as histamine may have some suppressive effect on cellular immunologicarle sponses. From this aspect the present experiment was undertaken to study the effect of chemical mediators such as bradykinin, histamine, serotonin and acetylcholineo n the production of antigen-inducedm igrationi nhibitoryf actors in the immune guinea pig peritoneal exudate cells. The results obtained were as follows
(1) The antigen-inducedM IF production was remarkablys uppressed by the addition of bradykinin or histamine. The migration inhibition percent by the treatment of bradykinin (10-6-10-7M) or histamine (10-4-10-6M) was about the same and the dose response fashion was observed between the dose of the drug (bradykinin or histamine) added and the inhibition percent.
(2) No suppressivee ffect on MIF productionw as observed by the treatment of serotonin or acetylcholine.
(3) The suppressive effect of bradykinin or histamine on MIF production was observed when bradykinin or histamine was added immediately after the addition of antigen, but the suppressive effect slightly decreased when it was added 30-60 min after the addition of antigen. The suppressive effect decreased ren-arkably when it was added 2 hr after the addition of antigen.
These findings suggest that bradykinin or histamine exerts its effects at an early stage in the MIF response, perhaps interfering with an antigendependents tage.
(4) The suppressive effect of bradykinin or histamine on MIF production was only slightly blocked by the treatment of H1antagonist, but clearly blocked by the treatment of H2-antagonist or H2agonist.
(5) No synergistic effect- of bradykinin and histamine was observed on the suppressive action of MIF production.
