Hemoglobin α-derived peptides VD-hemopressin (α) and RVD-hemopressin (α) are involved in electroacupuncture inhibition of chronic pain.

Introduction: Knee osteoarthritis (KOA) is a chronic degenerative bone metabolic disease that primarily affects older adults, leading to chronic pain and disability that affect patients' daily activities. Electroacupuncture (EA) is a commonly used method for the treatment of chronic pain in clinical practice. Previous studies indicate that the endocannabinoid system is involved in EA analgesia, but whether endocannabinopeptide VD-hemopressin (α) and RVD-hemopressin (α) derived from hemoglobin chains are involved in EA analgesia is unclear.

Activation of 5-HT Receptors in the Ventrolateral Orbital Cortex Produces Anti-Anxiodepressive Effects in a Rat Model of Neuropathic Pain.

The comorbidity of anxiety and depression frequently occurs in patients with neuropathic pain. The ventrolateral orbital cortex (VLO) plays a critical role in mediating neuropathic pain and anxiodepression in rodents. Previous studies suggested that 5-HT receptors in the VLO are involved in neuropathic pain.

Activation of 5-HT receptor in the ventrolateral orbital cortex produces antinociceptive effects in rat models of neuropathic and inflammatory pain.

The ventrolateral orbital cortex (VLO) is identified as an integral component of the endogenous analgesic system comprising a spinal cord - thalamic nucleus submedius - VLO - periaqueductal gray (PAG) - spinal cord loop. The present study investigates the effects of 5-HT receptor activation in the VLO on allodynia induced by spared nerve injury and formalin-evoked flinching behavior and spinal c-Fos expression in male SD rats, and further examines whether GABAergic modulation is involved in the effects evoked by VLO 5-HT receptor activation. We found an upregulation of 5-HT receptor expression in the VLO during neuropathic and inflammatory pain states.

5-HT Receptor Is Involved in Electroacupuncture Inhibition of Chronic Pain in the Spinal Cord.

Knee osteoarthritis (KOA) is a common and disabling condition characterized by attacks of pain around the joints, and it is a typical disease that develops chronic pain. Previous studies have proved that 5-HT, 5-HT, and 5-HT receptors in the spinal cord are involved in electroacupuncture (EA) analgesia. The 5-HT receptor plays antinociceptive role in the spinal cord.