[Assessment of the influence of pharmacologic substances on pressor vasomotor reflexes in anesthetized animals]

Causes accounting for differing results of experiments during studies on the effects of morphine and chlordiazepoxide upon the intensity of pressor vasomotor reflexes provoked by an electric stimulation of afferent fibers in the tibial nerve were investigated in tests set up on urethan and chloralose anesthetized animals. With this purpose in view the relationship between the amplitude of the vasomotor reflexes and the intensity of electric stimulation, as well as the nature of the drugs action upon the vasomotor reflexes, depending on the stimulation parameters adopted during their registration, were studied. The intensity and the nature of changes of the pressor vasomotor reflexes are shown to depend not only on the properties of the test drugs, but also upon the intensity of electric stimulation employed in the experiment during registration of the reflexes. The most adequate procedure for investigating the effect of pharmaceutics on the intensity of vasomotor reflexes, e. g. a study into the influence exerted by drugs on the threshold of the reflexes origination, is proposed.