Effect of succinylcholine, diazepam, and dantrolene on the urethral pressure profile of anesthetized, healthy, sexually intact male cats.
Effects of the neuromuscular blocking agent succinylcholine (n = 9), the centrally acting skeletal muscle relaxant diazepam (n = 11), and the directacting skeletal muscle relaxant dantrolene sodium (n = 8) on the urethral pressure profile were evaluated in anesthetized, healthy, sexually intact, adult male cats. Intravenous administration of succinylcholine (0.075 mg/kg of body weight) significantly decreased mean absolute pressure in the prostatic and post-prostatic/penile intraurethral segments by -9.5 and -6.5 mm of Hg, respectively (P = 0.0002 and P = 0.0006, respectively). Dantrolene (1.0 mg/kg, IV) significantly decreased mean prostatic and postprostatic/penile intraurethral segmental pressures by -3.5 and -2.8 mm of Hg, respectively (P = 0.005 and P = 0.0181, respectively). Diazepam (0.8 mg/kg, IV) did not significantly alter mean intraurethral segmental pressures. None of the drugs caused a change in segmental lengths of the urethra. These results indicate that skeletal muscle makes a substantial contribution to intraurethral tone in anesthetized, healthy, sexually intact male cats and that skeletal muscle relaxation may be successful in reducing prostatic and post-prostatic/penile urethral segmental tone in male cats. These results also suggest that dantrolene sodium may be valuable for the pharmacologic management of urethral disorders in male cats.
Straeter-Knowlen
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Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman 99164.
Marks
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Speth
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Wirth
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Knowlen
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D000768:Anesthesia, General / Q000662:veterinary; D000818:Animals; D002415:Cats / Q000502:physiology*; D003620:Dantrolene / Q000494:pharmacology*; D003975:Diazepam / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D011312:Pressure; D013390:Succinylcholine / Q000494:pharmacology*; D014521:Urethra / Q000187:drug effects* / Q000502:physiology
D003620:Dantrolene; D013390:Succinylcholine; D003975:Diazepam