New trypsin inhibitors are present in the coelomic fluid of the earthworm Lumbricus terrestris. 
Proteinase-inhibiting components of the coelomic fluid of the earthworm Lumbricus terrestris were examined.  Inhibition of proteinases of serine, aspartate and thiol families was tested.  Very strong inhibition was observed only in the case of trypsin.  Additional data suggest that the inhibition is related to proteins of molar mass of 42 kDa and 20 kDa, respectively.  These two proteins are present in the coelomic fluid in several forms which differ in their isoelectric points.