Identification of epidermal growth factor in mouse abdominal effusion.

Epidermal growth factor (mEGF)-like immunoreactive material(s) was identified in mouse abdominal effusion (approximately 2.1 ng/mg protein) by our enzyme immunoassay (EIA) for mEGF. This material(s) and mEGF from the submaxillary glands of male mice were virtually equivalent with respect to the molecular weight and the antigenicity. Also, on isoelectric focusing analysis, the mEGF-like material(s) identified in abdominal effusion gave a major peak at pH 4.2 and a minor one at pH 4.5. These results demonstrate that the mEGF-like material(s) found in abdominal effusion is a molecule identical to mouse submaxillary gland EGF. Further we found that sialoadenectomy did not cause a marked decrease in the level of mEGF in abdominal effusion, suggesting that the source of mEGF found in abdominal effusion is other than the submaxillary glands.