bq-123 and Neoplasms

To research the impact and mechanism of endothelin receptor A inhibitor BQ-123 combined with electroacupuncture on tibia cancer pain in rats.. Sprague-Dawley (SD) rats were randomly divided into sham group (SHAM group) and bone cancer pain model group (BCP group). The behavior of SD rats was measured. The histology of the right tibia was observed by hematoxylin-eosin (HE) staining. The remaining rats were randomly divided into model, BQ-123, electroacupuncture, and BQ-123+ electroacupuncture group. Behavioral tests were performed, and mechanical pain threshold (MWT) and thermal pain threshold (TWL) were measured. The expressions of. In the BCP group, bone structure was severely damaged, local tissue swelling was obvious, bone trabecula was missing, and bone cortex was discontinuous. The optical density of Glial fibrillary acidic protein (GFAP) and CD11b immunoreactive signal in BCP group was significantly increased, and most of the ETAR of endothelin receptor was comapped with NeuN, and a small part of GFAP was comapped with CD11b, but no comapped with CD11b. The AS score of BQ-123+ electroacupuncture group was significantly lower than that of BQ-123 group and electroacupuncture group (. BQ-123 may inhibit the activation of PI3K/Akt signal path combined with electroacupuncture to alleviate the effects of tibia cancer pain in rats.

Topics: Animals; Cancer Pain; Electroacupuncture; Humans; Neoplasms; Peptides, Cyclic; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Rats; Rats, Sprague-Dawley; Receptor, Endothelin A; Tibia

Cancer patients with bone metastases often suffer breakthrough pain. However, little progress has been made in the treatment of breakthrough pain and its associated mechanism(s) in the patient with cancer due to lacking of resembling and predictive animal models. We previously have demonstrated that endothelin-1 plays an important role in breakthrough cancer pain. In the present study, we have established an animal model of breakthrough cancer pain induced by endothelin-1. The animal model of breakthrough cancer pain is strictly followed the definition and meets the characteristics of breakthrough pain. The model is reliable, reproducible and easy to be produced. To our knowledge, this is the first report for establishing such an animal model. In addition, we also found that a selective ETA receptor antagonist BQ-123 could reverse endothelin-1 induced breakthrough pain. We further studied the characteristics of pain behaviors such as hind limb use score and voluntary wheel running as well as the electrophysiology of sciatic nerve fibers with the model. The murine model shows high resemblance compared to the breakthrough cancer pain in the patients with cancer clinically. It provides a platform for further study of the pathogenesis of breakthrough cancer pain and targeted intervention.

Topics: Action Potentials; Analgesics, Opioid; Animals; Breakthrough Pain; Cell Line, Tumor; Disease Models, Animal; Endothelin A Receptor Antagonists; Endothelin-1; Hindlimb; Male; Mice, Inbred C57BL; Morphine; Motor Activity; Neoplasm Transplantation; Neoplasms; Nerve Fibers; Peptides, Cyclic; Sciatic Nerve

Primary and metastatic cancers that effect bone are frequently associated with pain. Sensitization of primary afferent C nociceptors innervating tissue near the tumor likely contributes to the chronic pain and hyperalgesia accompanying this condition. This study focused on the role of the endogenous peptide endothelin-1 (ET-1) as a potential peripheral algogen implicated in the process of cancer pain. Electrophysiological response properties, including ongoing activity and responses evoked by heat stimuli, of C nociceptors were recorded in vivo from the tibial nerve in anesthetized control mice and mice exhibiting mechanical hyperalgesia following implantation of fibrosarcoma cells into and around the calcaneus bone. ET-1 (100 microM) injected into the receptive fields of C nociceptors innervating the plantar surface of the hind paw evoked an increase in ongoing activity in both control and tumor-bearing mice. Moreover, the selective ETA receptor antagonist, BQ-123 (3 mM), attenuated tumor-evoked ongoing activity in tumor-bearing mice. Whereas ET-1 produced sensitization of C nociceptors to heat stimuli in control mice, C nociceptors in tumor-bearing mice were sensitized to heat, and their responses were not further increased by ET-1. Importantly, administration of BQ-123 attenuated tumor-evoked sensitization of C nociceptors to heat. We conclude that ET-1 at the tumor site contributes to tumor-evoked excitation and sensitization of C nociceptors through an ETA receptor mediated mechanism.

Topics: Animals; Behavior, Animal; Cell Line, Tumor; Electrophysiology; Endothelin A Receptor Antagonists; Endothelins; Fibrosarcoma; Hot Temperature; Hyperalgesia; Male; Mice; Mice, Inbred C3H; Neoplasm Transplantation; Neoplasms; Nerve Fibers, Unmyelinated; Neural Conduction; Neurons, Afferent; Nociceptors; Peptides, Cyclic; Peripheral Nervous System Diseases

In this study we investigated the role of endothelin-1 (ET-1) and its peripheral receptor (ET-A) in carcinoma-induced pain in a mouse cancer pain model. Tumors were induced in the hind paw of female mice by local injection of cells derived from a human oral squamous cell carcinoma (SCC). Significant pain, as indicated by reduction in withdrawal thresholds in response to mechanical stimulation, began at four days after SCC inoculation and lasted to 28 days, the last day of measurement. Intra-tumor expression of both ET-1 mRNA and ET-1 protein were significantly upregulated compared to normal tissue, and local administration of the ET-A receptor selective antagonist, BQ-123 (100 microM) significantly elevated withdrawal thresholds, indicating the induction of an antinociceptive effect. These findings support the suggestion that ET-1 and ET-A receptors contribute to the severity of carcinoma-induced soft tissue cancer pain.

Topics: Analgesics, Opioid; Animals; Behavior, Animal; Cell Line, Tumor; Culture Media; Endothelin A Receptor Antagonists; Enzyme-Linked Immunosorbent Assay; Fluorescent Antibody Technique; Humans; Immunohistochemistry; Mice; Mice, Nude; Morphine; Neoplasms; Pain; Pain Measurement; Pain Threshold; Peptides, Cyclic; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger