[The cardiovascular response to gradual increase of intracranial pressure in experiments on animals (author's transl)].
Experiments were performed on dogs to examine the cardiovascular response (Cushing' reflex) to slow increase of intracranial pressure (ICP) by means of an epidural balloon. In contrast to the acute increase in ICP, a slow but constant increase of the cardiac output (CO) was observed, followed later by a short and steep increase of blood pressure, in various experiments with different ICP. In the range of ICP from 30 to 100 mm Hg a linear relation existed between the ICP and CO. The experiments indicate that with the slow ICP increase the so-called cardiovascular response does not occur, or only occurs rudimentarily, in contrast to a swift ICP-increase. It seems therefore obvious that a suppression of the cardiovascular reaction occurs which is dependent on the sympathicoadrenergic system by the parasympathetic fibers. The reflex mechanism is discussed. The release mechanism of the circulation reaction is not specifically dependent on pressure but is the consequence of a nonspecific lesion of the circulation centre in the medulla oblongata.
D000818:Animals; D002302:Cardiac Output; D002319:Cardiovascular System / Q000503:physiopathology*; D004285:Dogs; D005260:Female; D006973:Hypertension / Q000209:etiology; D007427:Intracranial Pressure; D008297:Male; D008526:Medulla Oblongata; D010275:Parasympathetic Nervous System / Q000503:physiopathology; D012018:Reflex; D013997:Time Factors
Cardiovasculäre Veränderungen bei der langsamen schrittweisen Erhöhung des intrakraniellen Druckes im Tierversuch.