PHARMACOLOGICAL CHARACTERIZATION OF LATEX EXTRACTS BY ISOLATED GUINEA-PIG TRACHEAL TISSUE

Latex manufacturing workers are exposed to a heterogeneous aerosol of organic compounds. Previous studies of latex workers involved in glove production indicate that these individuals are at risk of developing respiratory symptoms and impaired lung function. The effect of latex e xtracts on isolated guinea pig tracheal smooth muscles was studied usi ng latex water-soluble extracts obtained at different stages of the in dustrial process. Latex extracts were prepared as a 1:10 (w/v) solutio n. Dose-related contractions of nonsensitized guinea pig trachea were demonstrated using two latex extracts (latex 1 and latex 2). Latex I w as prepared from the native latex and latex 2 from a processed form of latex which was relatively free of soluble proteins, Pharmacologic st udies were performed by pretreating guinea pig tracheal tissue with dr ugs known to modulate smooth muscle contraction: atropine, indomethaci n, pyrilamine, nordihydroguaiacetic acid, acivicin, trimethobenzoic ac id and capsaicin, Constrictor effects of the dust extracts were inhibi ted by a wide variety of these agents, Atropine consistently and strik ingly reduced the contractile effects of these extracts. This observat ion may suggest an interaction of the extracts with parasympathetic ne rves or more directly with muscarinic receptors, Inhibition of contrac tion by blocking other mediators was less effective and varied with th e dust extract. Pretreatment with capsaicin did not change the constri ctor effects of latex 1 but enhanced the effects of latex 2. Depletion of neuropeptides, however, did not reduce the constrictor effect, We suggest that latex extracts cause dose-related airway smooth muscle co nstriction by nonimmunological mechanisms involving a variety of airwa y mediators and possibly cholinergic receptors, This effect is not dep endent on the presensitization of guinea pigs.