TY - JOUR T1 - Role of <em>µ</em>, <em>κ</em>, and <em>δ</em> Opioid Receptors in Tibial Inhibition of Bladder Overactivity in Cats JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 228 LP - 234 DO - 10.1124/jpet.115.226845 VL - 355 IS - 2 AU - Zhaocun Zhang AU - Richard C. Slater AU - Matthew C. Ferroni AU - Brian T. Kadow AU - Timothy D. Lyon AU - Bing Shen AU - Zhiying Xiao AU - Jicheng Wang AU - Audry Kang AU - James R. Roppolo AU - William C. de Groat AU - Changfeng Tai Y1 - 2015/11/01 UR - http://jpet.aspetjournals.org/content/355/2/228.abstract N2 - In α-chloralose anesthetized cats, we examined the role of opioid receptor (OR) subtypes (µ, κ, and δ) in tibial nerve stimulation (TNS)-induced inhibition of bladder overactivity elicited by intravesical infusion of 0.25% acetic acid (AA). The sensitivity of TNS inhibition to cumulative i.v. doses of selective OR antagonists (cyprodime for µ, nor-binaltorphimine for κ, or naltrindole for δ ORs) was tested. Naloxone (1 mg/kg, i.v., an antagonist for µ, κ, and δ ORs) was administered at the end of each experiment. AA caused bladder overactivity and significantly (P &lt; 0.01) reduced bladder capacity to 21.1% ± 2.6% of the saline control. TNS at 2 or 4 times threshold (T) intensity for inducing toe movement significantly (P &lt; 0.01) restored bladder capacity to 52.9% ± 3.6% or 57.4% ± 4.6% of control, respectively. Cyprodime (0.3–1.0 mg/kg) completely removed TNS inhibition without changing AA control capacity. Nor-binaltorphimine (3–10 mg/kg) also completely reversed TNS inhibition and significantly (P &lt; 0.05) increased AA control capacity. Naltrindole (1–10 mg/kg) reduced (P &lt; 0.05) TNS inhibition but significantly (P &lt; 0.05) increased AA control capacity. Naloxone (1 mg/kg) had no effect in cyprodime pretreated cats, but it reversed the nor-binaltorphimine–induced increase in bladder capacity and eliminated the TNS inhibition remaining in naltrindole pretreated cats. These results indicate a major role of µ and κ ORs in TNS inhibition, whereas δ ORs play a minor role. Meanwhile, κ and δ ORs also have an excitatory role in irritation-induced bladder overactivity. ER -