n-Formyl-methionyl-leucyl-phenylalanine (FMLP) is present in cotton dust and contracts isolated airway and cardiovascular smooth muscle.
Fedan-JS; Castranova-V; Ma-JH; Mo-CG; Frazer-DG
Cotton dust: proceedings of the Fourteenth Cotton Dust Research Conference, beltwide cotton research conferences, January 12-13, 1990, Las Vegas, Nevada. Jacobs RR, Wakelyn PJ, Domelsmith LN, eds. Memphis, TN: The National Cotton Council of America, 1990 Jan; :105-106
The effects of n-formyl-L-methionyl-leucine-phenylalanine (FMLP) and cotton dust on respiratory and cardiac smooth muscle function were studied in-vitro. Samples of DB-1/88 cotton dust were extracted with acetone and the dust samples and extracts were analyzed for FMLP and oxidized FMLP (FMoxLP). Open ring tracheal explants and aortic cardiac smooth muscle strips prepared from male guinea-pigs were incubated with FMLP or aqueous DB-1/88 dust extracts in the presence or absence of methacholine or phenylephrine. Muscle contractile activity was measured. A similar experiment was performed with neutrophils harvested from human blood donors. The cotton dust contained 103.2 micrograms per gram (microg/g) FMLP and 649.0microg/g FMoxLP. The acetone extracts contained 3.2 milligrams per gram (mg/g) FMLP and 6.0mg/g FMoxLP. FMLP induced tracheal and cardiac muscle contractions in a dose dependent manner. The concentrations inducing half maximal contractile activity were 91 and 14 nanomolar, respectively. Methacholine and phenylephrine desensitized both muscle preparations toward FMLP. The cotton dust extracts over the concentration range 0.1 to 3mg per milliliter (ml) caused a significant induction of contractile activity in both muscle preparations in the presence or absence of FMLP. The contractions occurred in muscle preparations desensitized by methacholine or phenylephrine. Neutrophils at concentration 10(7)/ml caused a maximal contraction in the tracheal explants. The authors conclude that FMLP in inhaled cotton dust may be involved in byssinosis by inducing contractions in the pulmonary vasculature and airway smooth muscle by a direct contractile effect and indirectly by recruitment of inflammatory cells.
Peptides; Cotton-dust; In-vitro-studies; Dose-response; Muscle-contraction; Blood-cells; Laboratory-animals;
Jacobs-RR; Wakelyn-PJ; Domelsmith-LN
Cotton dust: proceedings of the Fourteenth Cotton Dust Research Conference, beltwide cotton research conferences, January 12-13, 1990, Las Vegas, Nevada