[Participation of different groups of afferent fibers of mesenteric nerves in vasomotor reflexes].

The dependence of the magnitude and character of vasomotor reflexes on the amplitude of mesenteric nerve tetanic stimulation was studied in experiments with cats anesthetized with urethane and chloralose. A comparison of the stimulus amplitude reflex magnitude curves with the previously obtained data on electrical excitability of various groups of mesenteric nerves afferent fibres revealed that there are 3 groups of "vasomotor" afferents in mesenteric nerves: "fast" Adelta-fibres (conduction velocity above 8 m/s) the impulses of which evoke depressor or small pressor reflexes; "slow" Adelta-fibres (conduction velocity below 8 m/s) the impulses of which evoke pressor reflexes or interacting with impulses of lower-threshold "fast" Adelta-fibres, either decrease depressor reflexes evoked by impulses of these fibres or increase pressor reflexes evoked by these fibres impulses; C-fibres the impulses of which increase pressor reflexes evoked by impulses of "slow" Adelta-fibres.