Invertebrate model for study of macromolecular regulators of mucus secretion.

Large molecules which consistently stimulate hypersecretion in individual mucus-secretory sells in an 
animal system (the marine invertebrate Sipunculus) have been found in human 
serum and urine. This activity is heat-evoked in serum, heat-labile in 
urine. Heat-stable and heat-evoked factors were also found respectively in saliva 
and tears. The serum and urine factors withstood freeze-thawing. Activity of 
both factors was destroyed by pronase, and activity of the urine 
factor was destroyed by trypsin. After incubation with alphaamylase the factor 
in urine induced production of a very aberrant type of secretion. 
