Pain
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Clinical Trial Controlled Clinical Trial
Pain sensitivity, mood and plasma endocrine levels in man following long-distance running: effects of naloxone.
The effects of intense exercise on pain perception, mood, and plasma endocrine levels in man were studied under naloxone and saline conditions. Twelve long-distance runners (mean weekly mileage = 41.5) were evaluated on thermal, ischemic, and cold pressor pain tests and on mood visual analogue scales (VAS). Blood was drawn for determination of plasma levels of beta-endorphin-like immunoreactivity (BEir), growth hormone (GH), adrenocorticotrophic hormone (ACTH), and prolactin (PRL). ⋯ Plasma levels of BEir, ACTH, GH, and PRL were significantly increased post-run. The results show that long-distance running produces hypoalgesia and mood elevation in man. The effects of naloxone implicate endogenous opioid neural systems as mechanisms of some but not all of the run-induced alterations in mood and pain perception.
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A psychophysical analysis of acupuncture analgesia was carried out in which low back pain patients made visual analogue scale (VAS) responses both to their chronic pain and to different levels of experimental heat pain (5 sec exposures to 43-51 degrees C) before and after electroacupuncture. VAS (sensory) responses to chronic pain, direct temperature matches to chronic pain, and VAS (sensory) responses to experimental pain were reduced in an internally consistent manner 1-2 h after treatment. The magnitude of this analgesic response was similar for dermatomes within the region of chronic pain and acupuncture needle placement (lower back) as well as for dermatomes remote from needle placement and chronic pain (forearm). ⋯ VAS sensory and VAS affective analgesic responses to electroacupuncture treatment showed a delayed onset (1-24 h) to maximum effect and a duration of 10-14 days. Cumulative sensory and affective analgesic effects were observed at the end of 4 months of biweekly acupuncture treatments. The results of this analysis reveal the unique spatial and temporal properties of electroacupuncture analgesia and the extent to which it is mediated by at least two different mechanisms.