Abstract
1 Collagen degradation products (CDP) resulting from bacterial collagenase digestion were fractionated by gel filtration and their biological activities in rats were estimated. 2 CDP induced the following kinin-like effects: increase in permeability of skin blood vessels, contraction of the isolated intestine of the rat, depression of locomotor activity and of motor coordination. 3 The most active CDP fraction was CDP III containing peptides of mol. wt. < 1000 D with a high percentage of hydroxyproline. 4 As compared with bradykinin, CDP III was less active in the skin permeability test and was 15,000 to 20,000 fold less effective in induction of isolated intestine contraction. 5 Depression of the CNS induced by 30 microgram of CDP III administered into the brain ventricle was similar to that observed after 4 microgram of bradykinin given by the same route. 6 CDP III prolonged the duration of sleep evoked by thiopentone and enhanced the threshold of convulsion induced by pentazol. 7 The activity of CDP in comparison to other low molecular weight peptides is discussed.