Eosinophil chemotactic response to rat CGRP-1 is increased after exposure to trypsin or guinea-pig lung particulate fraction.
Calcitonin Gene-Related Peptide (CGRP) immunoreactive nerve fibres innervate the vasculature and epithelia of the peripheral airways of the guinea-pig lung. Guinea-pig eosinophils exhibit a concentration-dependent chemotactic response to rat Calcitonin Gene-Related Peptide-1 (rCGRP-1). The sequence rCGRP-1-(32-35) (valyl-glycyl-seryl-glutamic acid), which is identical to an eosinophil chemotactic factor of anaphylaxis (ECF-A) previously purified from guinea-pig lung (Goetzl, E. J. and Austen, F. (1975) Proc. Natl. Acad. Sci. USA 72, 4123-4127), was both more potent and more effective than rCGRP-1 in the chemotaxis assay. Products of rCGRP-1 tryptic digestion exhibited increased chemotactic activity compared to the intact peptide. Exposure of rCGRP-1 to a particulate fraction of guinea-pig lung also elevated its chemotactic activity, increasing the resultant potency by one hundred-fold. Resolution of pure and digested peptides by reverse-phase h.p.l.c. revealed evidence of endopeptidase activity in the lung particulate fraction. Elution times of rCGRP-1 cleavage fragments differed mostly from those of tryptic digestion.
Manley
H C
HC
Department of Zoology, University of Bristol.
Haynes
L W
LW
D000818:Animals; D015740:Calcitonin Gene-Related Peptide; D002630:Chemotactic Factors / Q000502:physiology*; D002631:Chemotactic Factors, Eosinophil / Q000502:physiology*; D002634:Chemotaxis, Leukocyte; D002851:Chromatography, High Pressure Liquid; D004804:Eosinophils / Q000502:physiology*; D006168:Guinea Pigs; D008168:Lung / Q000294:innervation* / Q000502:physiology; D009479:Neuropeptides / Q000302:isolation & purification / Q000502:physiology*; D014357:Trypsin / Q000494:pharmacology
D002630:Chemotactic Factors; D002631:Chemotactic Factors, Eosinophil; D009479:Neuropeptides; D014357:Trypsin; D015740:Calcitonin Gene-Related Peptide