Influence of beta-endorphin, somatostatin, substance P and vasoactive intestinal peptide on the proliferative response of human peripheral blood T lymphocytes to mercuric chloride

The influence of beta-endorphin, somatostatin, substance P (SP) and vasoactive intestinal peptide (VIP) was tested on the proliferative response to mercuric chloride of human peripheral blood T lymphocytes, cultured for 5 days. When beta-endorphin, 10(-8) M, was added 1 h after mercuric chloride, there was an enhancement of the response, while a slight suppression was obtained with a 10(-6) M concentration of SP and VIP. When beta-endorphin, 10(-7)-10(-9) M, somatostatin, 10(-6)-10(-9) M, and SP, 10(-11)-10(-12) M, were added 3 days after mercuric chloride, they enhanced the response. At 10(-6) M, SP gave a suppressive effect.