f-13640 and Spinal-Cord-Injuries

Spinal cord injury (SCI) above the lumbosacral level results in lower urinary tract dysfunction, including (1) detrusor hyperreflexia, wherein bladder compliance is low, and (2) a lack of external urethral sphincter (EUS) control, leading to detrusor-sphincter dyssynergia (DSD) with poor voiding efficiency. Experimental studies in animals have shown a dense innervation of serotonergic (5-HT) fibers and multiple 5-HT receptors in the spinal reflex circuits that control voiding function. Here, we investigated the efficacy of NLX-112 (a.k.a. befiradol or F13640), in regulating lower urinary tract function after T8 contusive SCI in rats. NLX-112 is a very potent, highly-selective, and fully efficacious 5-HT

Topics: Animals; Dose-Response Relationship, Drug; Electromyography; Female; Piperidines; Pyridines; Rats; Rats, Sprague-Dawley; Receptor, Serotonin, 5-HT1A; Serotonin 5-HT1 Receptor Agonists; Spinal Cord Injuries; Urethra; Urinary Bladder Diseases; Urinary Bladder, Neurogenic; Urinary Bladder, Overactive; Urinary Tract; Urination; Urodynamics

The selective, high-efficacy 5-HT(1A) receptor agonist, (3-chloro-4-fluoro-phenyl)-[4-fluoro-4-[[(5-methyl-pyridin-2-ylmethyl)-amino]-methyl]piperidin-1-yl]-methanone (F 13640) has been reported to produce long-term analgesia in rodent models of chronic nociceptive and neuropathic pain; it also preempts allodynia following spinal cord injury. Here, rats underwent spinal cord injury, fully developed allodynia, and were infused with saline or 0.63 mg/day of F 13640 for 56 days. Infusion was then discontinued, and further assessments of allodynia (vocalization threshold to von Frey filament stimulation, responses to brush and cold) were conducted for another 70 days. F 13640-induced analgesia persisted during this post-treatment period. The data offer initial evidence that high-efficacy 5-HT(1A) receptor activation produces an unprecedented curative-like action on pathological pain.

Topics: Analgesics; Animals; Behavior, Animal; Cold Temperature; Female; Infusions, Intravenous; Pain; Pain Measurement; Pain Threshold; Piperidines; Pyridines; Rats; Rats, Sprague-Dawley; Serotonin 5-HT1 Receptor Agonists; Spinal Cord Injuries; Touch; Vocalization, Animal

Central neuropathic pain after spinal cord injury (SCI) presents a challenging clinical problem with limited treatment options. [(3-chloro-4-fluoro-phenyl)-[4-fluoro-4-([(5-methyl-pyridin-2-ylmethyl)-amino]-methyl)piperidin-1-yl]]-methadone (F 13640) is a recently discovered very-high-efficacy, selective 5-HT1A receptor agonist that produces a remarkably powerful, central analgesia through unprecedented neuroadaptive mechanisms. In a rat model of spinal cord injury pain, we previously found that chronic infusion of F 13640 alleviated pain-like behaviors. Here, we report that infusion of 0.63 mg/day of F 13640 for 8 weeks starting 24 h before the induction of injury significantly attenuates the development of chronic allodynia-like behavior in rats sustaining a photochemically-induced, ischaemic injury of the dorsal laminae of the L3-L5 segments of the spinal cord. Importantly, the preemptive effect of F 13640 persisted for 2 months after treatment was discontinued. The data warrant the study of the possible effects of the early administration of F 13640 in patients sustaining spinal cord injury.

Topics: Animals; Behavior, Animal; Cold Temperature; Female; Motor Activity; Pain; Pain Measurement; Pain Threshold; Photochemistry; Physical Stimulation; Piperidines; Pyridines; Rats; Rats, Sprague-Dawley; Receptor, Serotonin, 5-HT1A; Serotonin Receptor Agonists; Spinal Cord Injuries; Time Factors; Vocalization, Animal