THE INFLUENCE OF CORAMINE ON CIRCULATORY CAROTID SINUS REFLEXES

¹ Ciba Research Laboratories

1. The blood-pressure-decreasing carotid sinus pressure reflex is weakened in urethanised rabbits under the influence of Coramine. An essential increase in the so-called residual blood-pressure is to be regarded as a sign of the increase in tone of the peripheral circulation.

2. Both in the urethanised rabbit and in the urethanised cat the blood-pressure-raising carotid occlusion reflex shows a larger rise in blood-pressure under the effect of Coramine than before its administration. This is also to be regarded as a sign of the peripheral vascular tonic effect. This result is obtained both with intact and severed aortic nerves.

3. Coramine produces in animals whose aortic nerve has been severed a larger rise in blood-pressure than in the intact animal.

4. The effect of Coramine on the carotid sinus itself can be excluded for the results reported. Coramine is capable only in high concentration of influencing the presso-receptors locally.