RFamide (RFa)-related peptides modulate pain processing in the mammalian CNS. The effects of these peptides are generally considered as 'anti-opioid'. They also decrease the rate of desensitization of acid-sensing ionic channels (ASICs), putative nociceptors in dorsal root ganglia neurons [C. Askwith et al. (2000) Neuron, 26, 133-141]. We have tested the role of mollusc-derived peptide, FMRFa (Phe-Met-Arg-Phe-amide) and its synthetic analogues in peripheral nociception. Here we demonstrate that RFa-related peptides powerfully excite the majority of C-fibres in the skin-nerve preparation of rat: 76% of 55 tested fibres with the conduction velocity below 2 m/s responded with long-lasting discharges to the application of peptides (20 microm). When injected subcutaneously in vivo (mice), they initiate nociceptive behaviour. We confirm the data on humans [S. Ugawa et al. (2002) J. Clin. Invest., 110, 1185-1190]: the activation of C-fibres by acid is inhibited by channel blocker of ASICs, amiloride. However, there is no correlation in the sensitivity of C-fibres to RFa peptides, protons and amiloride: 74% of tested RFa-sensitive C-fibres were insensitive to protons and in 67% of cases the response to peptides was insensitive to amiloride. Thus, powerful excitatory/algogenic action of RFa-related peptides cannot be interpreted solely in terms of their interaction with ASICs. The peptides do not activate any conductance in the somatic membrane of dorsal root ganglion neurons of rats and probably affect still unidentified molecular target(s) responsible for nociceptive signalling.
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http://dx.doi.org/10.1111/j.1460-9568.2004.03607.x | DOI Listing |
Calcif Tissue Int
September 2024
Department of Endocrinology, Seth GS Medical College and KEM Hospital, Acharya Donde Marg, Parel, Mumbai, Maharashtra, 400012, India.
Int J Hyperthermia
June 2023
Center of Minimally Invasive Treatment for Tumor, Department of Medical Ultrasound, Shanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China.
Purpose: Secondary hyperparathyroidism (SHPT) is a frequently encountered problem in patients with end-stage renal disease (ESRD) prior to renal transplantation (RTP), and the successful management of SPHP currently is challenging. In this study, we aimed to investigate the effectiveness of radiofrequency ablation (RFA) for SHPT as a bridge to RTP and to evaluate post-transplantation outcomes.
Methods: Patients with SHPT receiving RFA treatment were retrospectively reviewed, and those underwent RTP after ablation were enrolled.
Biomed Res Int
August 2018
Department of Radiation Oncology, Tianjin Medical University Cancer Institute and Hospital, Key Laboratory of Cancer Prevention and Therapy, Tianjin 300060, China.
Background: This study investigated the changes of circulating histones following radiofrequency ablation (RFA) in lung cancer patients and their impact on systemic inflammation.
Methods: Serial blood samples were obtained from a total of 65 primary and metastatic lung cancer patients undergoing RFA at 2 time points: pre-RFA and post-RFA within 48 h. Circulating histones, myeloperoxidase (MPO), and multiple inflammatory cytokines were measured.
Scand J Clin Lab Invest
November 2015
a Department of Oncology , First Hospital of Qinhuangdao, Qinhuangdao, Hebei Province, P.R. China.
Background: Radiofrequency ablation (RFA) has been increasingly accepted for the treatment of hepatocellular carcinoma (HCC). However, RFA has been associated with an obvious systemic inflammatory response, but little is known about the underlying mechanisms. Circulating histones are recently identified as pivotal inflammatory mediators.
View Article and Find Full Text PDFNeurosci Res
August 2006
Bogomoletz Institute of Physiology, Bogomoletz Str. 4, 01024 Kiev, Ukraine.
RFa-related peptides play a significant role in the processing of pain in the CNS of mammals. Recently it has been found that, when applied subcutaneously, these peptides elicit a powerful algogenic effect. The question arises whether this peripheral effect can be connected with the ability of RFa-related peptides to decrease the rate of desensitization of acid sensing ionic channels (ASICs) expressed in primary sensory neurons.
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