The authors studied the effects of increasing concentrations 10(-5)-10(-3) M) of four muscle relaxants (succinylcholine, d-tubocurarine, vecuronium, and atracurium) on histamine release from peripheral blood basophils and mast cells isolated from human lung parenchyma, skin tissues, and heart fragments. Basophil granulocytes released less than 5% of their histamine content when incubated with any one of the muscle relaxants tested. In contrast, mast cells showed a significant heterogeneity in response to different muscle relaxants. Succinylcholine did not induce histamine release from any type of mast cell, and only high concentrations of d-tubocurarine (10(-3) M) caused histamine release from skin and lung mast cells. Vecuronium concentration-dependently induced histamine release from skin and lung--but not from heart mast cells--to a maximum of 7.2 +/- 2.1% and 4.9 +/- 1.4%, respectively. Atracurium concentration-dependently caused significant histamine release from skin and lung mast cells to a maximum of 46.2 +/- 15.1% and 30.6 +/- 6.0%, respectively. Atracurium (5 x 10(-5) - 2 x 10(-4) M) also induced histamine release from heart mast cells. The histamine release process from both lung and skin mast cells caused by atracurium and vecuronium was extremely rapid (t1/2 = less than 1 min). The releasing activity of atracurium and vecuronium on lung and skin mast cells was not reduced, and not abolished, by lowering the temperature of the incubation buffer to 22 degrees C and 4 degrees C. Extracellular calcium did not affect the capacity of atracurium and vecuronium to induce histamine release from lung and skin mast cells.(ABSTRACT TRUNCATED AT 250 WORDS)