Experimentelle Untersuchungen in vivo und in vitro über die Wirkung von Autoabgasen und Kohlenmonoxid auf den Kreislauf von Säugetieren

Abstract

Experiments on the effect of exhaust gases and carbomonoxide on the circulation in animalsExhaust gases and carbon monoxide cause an increase of the blood flow of 400/0 in the brain of the cat. CO also has an increasing effect (20%) in the hind leg, where exhaust gases diminish the flow (50 ~ Although exhaust gases and CO (if not significantly) lower the average blood pressure, the flow does not follow in the same sense, so that peripheral resistance decreases or increases according to the experimental conditions.The rabbit also shows different reactions in the brain and hind leg after inhalation of exhaust gases, but this time in a reverse sense. While inhalation of exhaust gases produces a strong decrease in the hind leg of the cat, there is a significant reduction of flow (40 ~ in the rabbit's brain. This corresponds to the diminution of blood pressure and is contrary to all other measurements after inhalation of exhaust gases and CO. The peripheral resistance therefore remains unchanged.The heart frequency of the cat shows an increasing tendency after inhalation of exhaust gases and CO, but never a significant variation. The rabbit's heart frequency even shows a reverse reaction, namely a permanent falling tendency. The respiration frequency of both animals remains unchanged during all experiments. These results correspond to the investigations mentioned in the introduction, which led to a diminution of blood pressure after experimental inhalation of CO. On the contrary CO cannot be the determining factor oft the resulting, disturbances. It is supposed that the diminution of the peripheral resistance after inhalation of CO is due to the refusal of the vasoconstrictory nerve impulses. Exhaust gases, on the contrary, seem to influence directly the muscle cells of the blood vessels.