Abstract: Central interleukin 1 (IL 1) plays very important roles in mediating the neural, endocrine, and behavioral responses to stressors. Furthermore, cardiovascular and endocrine responses to interleukin 1β are similar to stress. To test the roles of central IL 1 in hypertension induced by stress (footshock or conditional fear emotional stress), intracerebral ventricular (ICV) injection of IL 1β or IL 1ra was performed on male Sprague Dawley rats. We observed that: 1) ICV injection of interleukin 1β induced pressor responses. 2) Hypertension induced by interleukin 1β was blocked by ICV injection of an IL 1 antagonist, IL 1ra. 3) ICV injection of IL 1ra attenuate the pressor response induced by footshock but intravenous injection of IL 1ra did not significantly reduce this response. 4) The hypertensive response to conditioned fear stimuli was reversed by ICV injection of IL 1ra. These results suggested that the pressor response induced by footshock or conditioned fear emotional stimuli is mediated by central interleukin 1.

Key words: hypertension, interleukin 1, interleukin 1 receptor antagonist, footshock, conditioned fear emotional stimuli