Substanz P-Gehalt und permeabilitätserhöhende Wirkung in verschiedenen Gehirngebieten

Summary

1. Four parts of human brain were extracted by successive ammonium sulphate and acetic acid-ether precipitations. The resulting extracts contained substance P but were found to be free of other substances which are known to influence capillary permeability (acetyl choline, adrenergic amines, histamine, serotonin, ATP, ADP, AMP).

2. The extracts were tested for substance P activity on the guinea pig's ileum and for activity in increasing capillary permeability on the rabbit's skin. The substance P content was found to be 719 units/g in substancia nigra, 120 units/g in basal ganglia, 34 units/g in cortex, < 2 units/g in cerebellum. Equal increase in capillary permeability was produced by extracts corresponding to 40–50 mg of substancia nigra, 200–300 mg of basal ganglia, 300–400 mg of cortex, 600–800 mg of cerebellum. This shows a close relation between substance P content and effectiveness in increasing capillary permeability in four parts of brain.

3. Since extracts of these four parts with equal activity in increasing permeability contained different amounts of substance P, other material capable of increasing capillary permeability must be present. This becomes appearent especially when larger quantities of the extracts had to be injected. By means of paper chromatography a separation could be achieved in intestinal but not in brain extracts.

4. It seems to be possible that substance P enables those parts of the brain which are rich in it to have particularly high rates of exchange, either potential or permanent, between the capillaries and the surrounding tissue.