Study on the Specific Expression of Infrared Radiation Temperature on the Body Surface of Acupoint in Rats with Chronic Myocardial Ischemic Injury

Abstract

Background: Infrared thermal imaging technology was used to observe the changes in infrared radiation temperature at acupoints in rats caused by chronic myocardial ischemia injury.

Objective: This study aims to compare the difference of body surface infrared radiation temperature information of three groups of acupoints: bilateral Neiguan (PC6), bilateral Yanglingquan (GB33), and bilateral Sham Acupoints (SA) in the pathological state of myocardial ischemia injury, and to explore the relationship between acupoints and viscera state.

Methods: SPF adult Wistar male rats (n = 20) were randomly divided into a control (CTL; n = 10) and an isoproterenol group (ISO; n = 10). Chronic myocardial injury was induced in rats by subcutaneous injection of isoproterenol hydrochloride for 14 d. On the second day after the establishment of the model, the serum levels of cardiac troponin (cTnI) and creatine kinase isoenzyme (CK-MB) were measured by enzyme-linked immunosorbent assay (ELISA). The morphological changes of the myocardial tissue in the two groups were observed by hematoxylin-eosin (HE) staining and their pathological scores were evaluated, which was then used to determine the myocardial ischemic injury. Two days before and after the establishment of the model, the electrocardiograms (ECG) of the two groups of rats were recorded by the (ECG) data acquisition system, and the infrared thermal imaging platform was used to detect the temperature of the six acupoints.

Results: 1. After subcutaneous injection of isoproterenol hydrochloride for 14 days, the ST segment of the ECG decreased in the ISO group compared with that of the CTL group; 2. Myocardial tissue injury was serious in the ISO group compared to the CTL group; 3. Serum cTn-I and CK-MB were significantly increased (P <0 01) in the ISO group, compared to that in the CTL group; 4. The infrared radiation temperature on the body surface of bilateral Neiguan (PC6) acupoints decreased significantly in the ISO group, compared to that of the CTL group.

Conclusion: Infrared thermal imaging technology can be used to detect the changes in the energy state of acupoints. Chronic myocardial ischemic injury can cause a decrease in IR temperature on the body surface of bilateral Neiguan (PC6) acupoints, suggesting that visceral diseases can lead to changes in the energy metabolism of acupoints.

Keywords: Acupoints; acupoint sensitization; acupuncture; chronic myocardial ischemia; infrared thermal imaging; neiguan (PC6).