HYPERALGESIC AND HYPOALGESIC EFFECTS OF H UMAN AND ANIMAL BLOOD-SERUMPROTEINS

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 or the seat blood ser um was divided in six subfractions by ion-exchange chromatography. One of these subfractions clearly showed hyperalgesic properties, while t he others had an opposite effect. The collagenase hydrolysate of the s ame protein fraction had an analgetic activity. The results of this an d previous studies suggest the occurrence of one more nociception-regu lating protein-peptide system in mammals.