Details

Autor(en) / Beteiligte

• Kameoka, Hiroshi
• Shiraiwa, Yasuo
• Fukaya, Yasuo
• Yokota, Takashi
• Shishido, Keiichi
• Yamaguchi, Osamu

Titel

Effect of Naloxone on the Bladder Activity of Rabbits with Acute Spinal Injury

Ist Teil von

• International journal of urology, 1998-11, Vol.5 (6), p.588-594

Ort / Verlag

Oxford, UK: Blackwell Publishing Ltd

Erscheinungsjahr

1998

Link zum Volltext

Quelle

Wiley Online Library Journals Frontfile Complete

Beschreibungen/Notizen

• Background: Naloxone enhances bladder activity in patients with chronic spinal cord injury. However, there are few reports on naloxone for bladder morbidity in acute spinal cord injury. Methods: We performed a prospective, controlled study of the effects of naloxone on bladder function in rabbits with and without surgical transection of the spinal cord at the 10th thoracic vertebra. Acute and chronic stages of injury were defined according to bladder function. Naloxone was given intravenously at both stages, and intrathecally at the acute stage. Bladder activity was monitored by cystometry. Blood concentrations of methionine‐enkephalin were measured by radioimmunoassay. Results: Spinal cord injuries were acute 1 or 2 days after surgery, and chronic after 1 or 2 weeks. Bladder capacity significantly decreased after 0.01 mg of intravenous naloxone in uninjured control rabbits, and after 0.03 mg of intravenous naloxone in rabbits with chronic‐phase injuries. During the acute‐injury phase, 0.3 mg of intravenous naloxone, or 0.02 mg of intrathecal naloxone, was necessary to evoke the micturition reflex. No significant changes in blood enkephalin levels were seen before or after spinal cord injury. Conclusion: In rabbits with acute spinal cord injury, intrathecal naloxone evoked the micturition reflex at a much lower dose than did intravenous naloxone. Intrathecal naloxone promises to become a new therapy for the acute stage of spinal cord injury for active recovery of bladder function, and could replace current therapy.