Pain, 21 (1985) 357-367 Elsevier 357 PAI 00740 Elevation of Pain Threshold by Vaginal Stimulation in Women Beverly Whipple and Barry R. Komisaruk Institute of Animal Behavior, Rutgers-The State University, 101 Warren Street, Newark, NJ 07102 (U.S.A.) (Received 2 August 1984, accepted 26 November 1984) zyxwvutsrqponmlkjihgfedcbaZY Summary In 2 studies with 10 women each, vaginal self-stimulation significantly increased the threshold to detect and tolerate painful finger compression, but did not signifi- cantly affect the threshold to detect innocuous tactile stimulation. The vaginal self-stimulation was applied with a specially designed pressure transducer assembly to produce a report of pressure or pleasure. In the first study, 6 of the women perceived the vaginal stimulation as producing pleasure. During that condition, the pain tolerance threshold increased significantly by 36.8% and the pain detection threshold increased significantly by 53%. A second study utilized other types of stimuli. Vaginal self-stimulation perceived as pressure significantly increased the pain tolerance threshold by 40.3% and the pain detection threshold by 47.4%. In the second study, when the vaginal stimulation was self-applied in a manner that produced orgasm, the pain tolerance threshold and pain detection threshold in- creased si~ificantly by 74.6% and 106.7% respectively, while the tactile threshold remained unaffected. A variety of control conditions, including various types of distraction, did not significantly elevate pain or tactile thresholds. We conclude that in women, vaginal self-stimulation decreases pain sensitivity, but does not affect tactile sensitivity. This effect is apparently not due to painful or non-painful distraction. Introduction Previous studies in this laboratory have shown that vaginal stimulation (VS) in rats blocks behavioral responses to noxious stimulation (e.g. leg withdrawal to foot pinch ]lS], vocalization to tail shock [16], and tail flick away from radiant heat [24]). VS was far more effective than a standard analgesic dose of morphine sulfate (2 0304-3959/85/$03.30 0 1985 Elsevier Science Publishers B.V. (Biomedical Division)