title: [K+, H+ and Ca++ concentrations in the perivascular fluid as a factor in the regulation of the lumina of the vessels of the pia mater].
abstract: The author separed the vascular vessels of pia mater with a size of 20-150 microns in cats under penthobarbital narcosis. The perivascular area of the vessels was perfused by an artificial fluid with varying concentrations of potassium, hydrogen and calcium. The local contraction of the smooth vascular musculature was induced by stimulation  with rectangular impulses by means of electrodes introduced by micromanipulators in immediate vicinity of a vessel. The changes were recorded by means of microphotographic images of the vessels. It was established that the contraction of the vessels was observed when there was a lack of potassium or at concentration of 100 meq/l. There was no change at 2,5-3,0 and at 50-60 meq/l of potassium. Vasodilatation was found at 10-20 meq/l. Electrical stimulation caused stronger contraction of the vessel, when there was a lack of potassium in comparison with the norm (2,7 meq/l). The increase of potassium caused a reduction of the dimensions of the effect due to electrical stimulation. The vascular dilatation, induced by 10-20 meq/l of potassium was not affected by the increase of the calcium concentration (6-9 meq/l) in artificial fluid. The vasodilatation, induced by an increase of hydrogen, was abolished by raising the concentration of calcium in the artificial fluid. The obtained results were discussed.
mesh_terms: D000818:Animals; D001808:Blood Vessels / Q000502:physiology*; D001826:Body Fluids / Q000502:physiology*; D002118:Calcium / Q000502:physiology*; D002413:Cations, Divalent; D002414:Cations, Monovalent; D002415:Cats; D004106:Dilatation; D004558:Electric Stimulation; D004594:Electrophysiology; D006859:Hydrogen / Q000502:physiology*; D010841:Pia Mater / Q000098:blood supply*; D011188:Potassium / Q000502:physiology*
chemical_list: D002413:Cations, Divalent; D002414:Cations, Monovalent; D006859:Hydrogen; D011188:Potassium; D002118:Calcium
vernacular_title: Kontsentratsiite na K+, H+ i Ca++ v perivaskularnata technost kato faktor v regulatsiiata na prosveta na sudovete na pia mater