Regional blood volume changes of the lungs in response to the vegetative nerves stimulation

Significant regional differences in the values of blood volume change response within one lobe of the lung upon the cervic sympathetic and parasympathetic nerves electrical stimulation have been demonstrated through the use of regional lung electroplethysmography method under the conditions of a minimal surgical trauma in dogs, cats, and rabbits kept in a supine position. The vascular component of the reaction has been isolated. It consists in blood volume increase in the lungs during the vagus stimulation and blood volume decrease during the sympathetic nerves stimulation. This response is very well manifested in central portions of the lung lobes and decreases progressively in peripheral direction. Blood volume changes due to different body positions relative to the gravitation direction have been demonstrated. Mechanisms of regional differences in blood volume changes have been discussed. The gravitation factor has been suggested to be also responsible for the formation of the neurogenic vasomotoric reaction in lungs.