endothelin-1 and Pain--Postoperative

Pain induced by surgery is a dynamic symptom, which may be quite variable even in the same surgical procedures. The purpose of this study was to investigate the analgesic effect of far infrared rays on the patients during the postoperative period of total knee arthroplasty (TKA). The selection and application of analgesic methods after the orthopedic surgery are therefore valuable for advanced studies.. The quasi-experimental design with a total five consecutive days of far infrared ray (FIR) thermal therapy was employed in this study.. The study involved 41 participants assigned by register code entry on computer to either the intervention or the control group.. The FIR pads were applied on the acupoints of ST37 (Shang Chu Hsu), ST38 (Tiao Kou), ST39 (Hsia Chu Hsu), and ST40 (Feng Lung) of the patients involved in the experimental group from the third day to the fifth day after the TKA.. The analgesic effect was evaluated via the pain intensity of the numeric rating scale (NRS) level and serum concentration of interleukin-6 (IL-6) and endothelin-1 (ET-1).. The FIR showed that the significant effects are on relieving pain and lowering the levels of IL-6 and ET-1. The results cannot only be the reference for the postoperative pain relief of TKA, but it can also be the database of another clinical application.. This study demonstrated that the FIR can lower the NRS of pain and thus reduce the discomfort experienced by the patient. Findings indicated that effective application of FIR decreased the serum level of IL-6 and ET-1, which represent the subjective indicator of pain.

Topics: Acupuncture Points; Aged; Aged, 80 and over; Analgesia; Arthroplasty, Replacement, Knee; Endothelin-1; Female; Hot Temperature; Humans; Hyperthermia, Induced; Infrared Rays; Interleukin-6; Knee; Knee Joint; Male; Middle Aged; Outcome Assessment, Health Care; Pain Measurement; Pain, Postoperative; Range of Motion, Articular; Severity of Illness Index

Endothelin-1 is known to be a potent vasoconstrictor. Administration of endothelin-1 to the central nervous system (CNS) induces antinociceptive effects. Nociceptive stimuli affect dorsal root ganglion (DRG) neurons and neurons/astrocytes/microglia in the dorsal horn of the spinal cord. Surgical incision in the plantar aspect of the rat hindpaw is a model for postoperative pain, and withdrawal thresholds reportedly decrease around the incision. We hypothesized that intrathecal endothelin-1 would have antinociceptive effects in this model, and affect DRG neurons and microglia/neurons in the dorsal horn. Intrathecal endothelin-1 partially restored the withdrawal threshold (which was decreased by plantar incision). BQ-123, and BQ-788 (specific endothelin ET(A)- and ET(B)-receptor antagonists, respectively) attenuated the increase in withdrawal threshold induced by endothelin-1. Phosphorylation of extracellular signal-regulated kinase (ERK) in DRG neurons and microglial activation/ERK phosphorylation in the dorsal horn were observed following the incision. Endothelin-1 decreased the incision-induced increase in the numbers of phosphorylated ERK-positive neurons in DRG and activated microglia in the dorsal horn, without affecting the numbers of phosphorylated ERK-positive neurons in the dorsal horn. BQ-123 or BQ-788 partially suppressed these endothelin-1-induced alterations. Our results show that the pain threshold, which is decreased by surgical stimuli, is partially restored by intrathecal endothelin-1 through both endothelin ET(A)- and ET(B)- receptors in DRG neurons and microglia in the spinal cord. Endothelin-1 administration to the CNS may be worth considering as a new candidate for the treatment of postoperative pain and to mitigate prolonged periods of pain.

Topics: Analgesics; Animals; Behavior, Animal; Disease Models, Animal; Endothelin-1; Extracellular Signal-Regulated MAP Kinases; Flavonoids; Ganglia, Spinal; Injections, Spinal; Male; Microglia; Oligopeptides; Pain Measurement; Pain Threshold; Pain, Postoperative; Peptides, Cyclic; Phosphorylation; Piperidines; Posterior Horn Cells; Protein Kinase Inhibitors; Rats; Rats, Sprague-Dawley; Receptor, Endothelin A; Receptor, Endothelin B; Time Factors