{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,26]],"date-time":"2025-10-26T21:18:54Z","timestamp":1761513534513,"version":"3.44.0"},"reference-count":36,"publisher":"BMJ","issue":"2","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["Heart"],"accepted":{"date-parts":[[1999,2,22]]},"published-print":{"date-parts":[[1999,8,1]]},"abstract":"<jats:sec>\n                  <jats:title>OBJECTIVE<\/jats:title>\n                  <jats:p>To determine whether changes in plasma concentrations of \u03b2 endorphins alter angina threshold and peripheral pain threshold in patients with stable angina.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>DESIGN<\/jats:title>\n                  <jats:p>Latin square design comparison of angina thresholds by exercise treadmill test and peripheral pain thresholds using a radiant heat source in eight patients with stable angina under control conditions, after stimulation of pituitary \u03b2 endorphin release by ketoconazole, after suppression of pituitary \u03b2 endorphin release by dexamethasone, and after blockade of opioid receptors by intravenous naloxone.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>RESULTS<\/jats:title>\n                  <jats:p>An approximately fivefold increase in circulating concentrations of \u03b2 endorphins was found after administration of ketoconazole (mean (SEM): 13.9 (1.2) <jats:italic>v<\/jats:italic> 73.8 (6.2) pg\/ml; p\u2009&lt;\u20090.05), which was associated with an increase in peripheral pain threshold to a radiant heat source (time to onset of pain perception 72 (19)<jats:italic>v<\/jats:italic> 123 (40) seconds; p\u2009&lt;\u20090.05), but no significant difference in angina threshold. A reduction in circulating concentrations of \u03b2 endorphins after pretreatment with dexamethasone was statistically non-significant (13.9 (1.2)<jats:italic>v<\/jats:italic> 9.0 (1.5) pg\/ml; NS) and was not associated with any change in either peripheral pain or angina thresholds. No effects were seen after blockade of opioid receptors by previous administration of intravenous naloxone.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>CONCLUSIONS<\/jats:title>\n                  <jats:p>Increased plasma concentrations of \u03b2 endorphins alter peripheral pain threshold but not angina threshold in patients with stable angina pectoris.<\/jats:p>\n               <\/jats:sec>","DOI":"10.1136\/hrt.82.2.204","type":"journal-article","created":{"date-parts":[[2014,10,22]],"date-time":"2014-10-22T15:31:45Z","timestamp":1413991905000},"page":"204-209","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":17,"title":["Effect of raised plasma \u03b2 endorphin concentrations on peripheral pain and angina thresholds in patients with stable angina"],"prefix":"10.1136","volume":"82","author":[{"given":"N F","family":"Jarmukli","sequence":"first","affiliation":[{"name":"Cardiology Section, VA Medical Center, Salem, and University of Virginia Health Sciences Center, Charlottesville, Virginia, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"J","family":"Ahn","sequence":"additional","affiliation":[{"name":"Cardiology Section, VA Medical Center, Salem, and University of Virginia Health Sciences Center, Charlottesville, Virginia, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"A","family":"Iranmanesh","sequence":"additional","affiliation":[{"name":"Cardiology Section, VA Medical Center, Salem, and University of Virginia Health Sciences Center, Charlottesville, Virginia, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"D C","family":"Russell","sequence":"additional","affiliation":[{"name":"Cardiology Section, VA Medical Center, Salem, and University of Virginia Health Sciences Center, Charlottesville, Virginia, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[1999,8,1]]},"reference":[{"key":"2025092013184466000_82.2.204.1","unstructured":"Braunwald E (1997) Heart disease: a textbook of cardiovascular medicine (WB Saunders, Philadelphia), 5th ed."},{"key":"2025092013184466000_82.2.204.2","doi-asserted-by":"publisher","DOI":"10.1016\/0002-8703(82)90352-0"},{"key":"2025092013184466000_82.2.204.3","doi-asserted-by":"publisher","DOI":"10.1161\/01.CIR.32.1.138"},{"key":"2025092013184466000_82.2.204.4","unstructured":"Ruch TC (1955) Pathophysiology of pain. in Textbook of physiology. ed Fulton JF (WB Saunders, Philadelphia), p 358."},{"key":"2025092013184466000_82.2.204.5","doi-asserted-by":"publisher","DOI":"10.1126\/science.150.3699.971"},{"key":"2025092013184466000_82.2.204.6","doi-asserted-by":"publisher","DOI":"10.1016\/0033-0620(92)90031-T"},{"key":"2025092013184466000_82.2.204.7","doi-asserted-by":"publisher","DOI":"10.1016\/0006-8993(93)91433-S"},{"key":"2025092013184466000_82.2.204.8","doi-asserted-by":"publisher","DOI":"10.1152\/jn.1993.70.1.200"},{"key":"2025092013184466000_82.2.204.9","doi-asserted-by":"publisher","DOI":"10.1016\/0304-3959(94)90055-8"},{"key":"2025092013184466000_82.2.204.10","doi-asserted-by":"publisher","DOI":"10.1038\/nm0995-910"},{"key":"2025092013184466000_82.2.204.11","unstructured":"Mehler WR (1962) The anatomy of the so-called \u201cpain tract\u201d in man: an analysis of the course and distribution of the ascending fibers of the fascilculus anterolateralis. in Basic research in paraplegia. eds French JD Porter RW (Thomas, Springfield), p 26."},{"key":"2025092013184466000_82.2.204.12","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(94)92755-3"},{"key":"2025092013184466000_82.2.204.13","unstructured":"Fields HL Basbaum AI (1984) Endogenous pain control mechanisms. in Textbook of pain. eds Wall PD Melzack Z (Churchill Livingstone, Edinburgh), pp 143\u2013152."},{"key":"2025092013184466000_82.2.204.14","unstructured":"Fields HL (1981) An endorphin-mediated analgesia system; 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