[The hyper- and hypoalgesic effects of human and animal blood serum proteins]

The protein fractions precipitated by ammonium sulfate from the bovine, human and Greenland's seal blood sera enhanced the pain sensitivity of mice, rats and rabbits. The proteins fraction of the seal blood serum was divided in six subfractions by ion-exchange chromatography. One of these subfractions clearly showed hyperalgesic properties, while the others had an opposite effect. The collagenase hydrolysate of the same protein fraction had an analgetic activity. The results of this and previous studies suggest the occurrence of one more nociception-regulating protein-peptide system in mammals.