title: Ameliorative effects of amiloride and pralidoxime in chronic constriction injury and vincristine induced painful neuropathy in rats.
abstract: The present study was designed to investigate the ameliorative effects of clinically available drugs, with Na+/Ca2+ and Na+/H+ exchange inhibitory actions, in chronic constriction injury and vincristine induced painful neuropathy in rats. Sciatic nerve ligation and vincristine treatment (50 microg/kg for 10 days) was employed to induce neuropathy in rats. Paw pressure, von Frey hair, acetone drop, and tail heat immersion tests were performed to assess degree of mechano-hyperalgesia, mechano-allodynia, cold chemical allodynia and spinal thermal sensation respectively. Axonal degeneration of sciatic nerve was assessed histopathologically. The levels of thio-barbituric acid reactive species, reduced glutathione, and total calcium were determined to assess biochemical alterations. Amiloride (15 mg/kg i.p.), Na+/Ca2+ and Na+/H+ exchange inhibitor, and pralidoxime (20 mg/kg i.p.), Na+/Ca2+ exchange inhibitor, were administered for 10 consecutive days starting from the day of surgery or vincristine administration. Sciatic nerve ligation and vincristine treatment resulted in significant axonal degeneration, development of mechano-hyperalgesia, mechano-allodynia, cold chemical allodynia and spinal heat hyperalgesia and also resulted in rise in thio-barbituric acid reactive species, total calcium and decrease in reduced glutathione levels. Administration of amiloride and pralidoxime attenuated chronic constriction injury and vincristine induced axonal degeneration and reduction of nociceptive threshold along with reduction in calcium levels and oxidative stress. The observed anti-nociceptive effects of amiloride and pralidoxime may possibly be attributed to inhibition of Na+/Ca2+ and Na+/H+ exchangers with subsequent decrease in Ca2+ ions and oxidative stress.
authors.affiliation: Department of Pharmaceutical Sciences and Drug Research, Punjabi University, Patiala-147002, India.
authors.forename: Arunachalam
authors.initials: A
authors.lastname: Muthuraman
authors.forename: Amteshwar Singh
authors.initials: AS
authors.lastname: Jaggi
authors.forename: Nirmal
authors.initials: N
authors.lastname: Singh
authors.forename: Dhandeep
authors.initials: D
authors.lastname: Singh
mesh_terms: D000584:Amiloride / Q000627:therapeutic use*; D000818:Animals; D000972:Antineoplastic Agents, Phytogenic; D001369:Axons / Q000473:pathology; D002118:Calcium / Q000378:metabolism; D002801:Cholinesterase Reactivators / Q000627:therapeutic use*; D003080:Cold Temperature; D003251:Constriction, Pathologic / Q000188:drug therapy* / Q000473:pathology; D004232:Diuretics / Q000627:therapeutic use*; D005260:Female; D006358:Hot Temperature; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects; D010147:Pain Measurement / Q000187:drug effects; D010523:Peripheral Nervous System Diseases / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology; D010812:Physical Stimulation; D011220:Pralidoxime Compounds / Q000627:therapeutic use*; D011312:Pressure; D051381:Rats; D017208:Rats, Wistar; D020426:Sciatic Neuropathy / Q000473:pathology; D019831:Sodium-Calcium Exchanger / Q000037:antagonists & inhibitors; D017923:Sodium-Hydrogen Exchangers / Q000037:antagonists & inhibitors; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014750:Vincristine
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D002801:Cholinesterase Reactivators; D004232:Diuretics; D011220:Pralidoxime Compounds; D019831:Sodium-Calcium Exchanger; D017923:Sodium-Hydrogen Exchangers; D017392:Thiobarbituric Acid Reactive Substances; D014750:Vincristine; D000584:Amiloride; C028797:pralidoxime; D002118:Calcium