Factors influencing the altered pain perception in the spontaneously hypertensive rat

摘要: Summary Recent studies have demonstrated a hypoalgesia in hypertensive subjects. This study reports and evaluates factors responsible for the expression of hypoalgesic behavior by genetically rats Okamoto-Aoki strain (SHR) as compared to normotensive age-matched Wistar-Kyoto (WKY). Analgesiometric assays were conducted hot plate method. SHR's was reversed subcutaneously administered naloxone. The intravenous administration naloxone did not alter arterial pressure heart rate either SHR or WKY. Subcutaneous peripherally acting ganglionic blocker hexamethonium bromide at dose which lowered mean blood thus decreased tonic baroreceptor stimulation, concomitantly induced hyperalgesia Denervation sinoaortic baroreceptors failed SHR. right vagal nerve trunk with associated cardiopulmonary afferents resulted reduction produced hyperalgesic WKY sham operated controls over 4 week period. These data suggest possible physiological role afferent systems concomitant regulation resting responsiveness aversive environmental stimuli. A discussion interaction between pain regulatory potential substrates onset maintenance hypertension is provided.