Research article

Vasodilative effects of prostaglandin E₁ derivate on arteries of nerve roots in a canine model of a chronically compressed cauda equina

Masayoshi Shirasaka^{* 1} , Bunji Takayama^{* 2} , Miho Sekiguchi^{* 2} , Shin-ichi Konno^{* 2} and Shin-ichi Kikuchi^{* 2}

¹Department of Pharmacy, Fukushima Medical University Hospital, 1-Hikarigaoka, Fukushima City, Fukushima 960-1295, Japan

²Department of Orthopaedic Surgery, Fukushima Medical University School of Medicine, 1-Hikarigaoka, Fukushima City, Fukushima 960-1295, Japan

author email corresponding author email* Contributed equally

BMC Musculoskeletal Disorders 2008, 9:41doi:10.1186/1471-2474-9-41

Published:	8 April 2008

Abstract

Background

Reduction of blood flow is important in the induction of neurogenic intermittent claudication (NIC) in lumbar spinal canal stenosis. PGE₁ improves the mean walking distance in patients with NIC type cauda equina compression. PGE₁ derivate might be effective in dilating blood vessels and improving blood flow in nerve roots with chronically compressed cauda equina. The aim of this study was to assess whether PGE₁ derivate has vasodilatory effects on both arteries and veins in a canine model of chronic cauda equina compression.

Methods

Fourteen dogs were used in this study. A plastic balloon inflated to 10 mmHg was placed under the lamina of the 7th lumbar vertebra for 1 week. OP-1206-cyclodextrin clathrate (OP-1206-CD: prostaglandin E₁ derivate) was administered orally. The blood vessels of the second or third sacral nerve root were identified using a specially designed surgical microscope equipped with a video camera. The diameter of the blood vessels was measured on video-recordings every 15 minutes until 90 minutes after the administration of the PGE₁ derivate.

Results

We observed seven arteries and seven veins. The diameter and blood flow of the arteries was significantly increased compared with the veins at both 60 and 75 minutes after administration of the PGE₁ derivate (p < 0.05). Blood flow velocity did not change over 90 minutes in either the arteries or veins.

Discussion

The PGE₁ derivate improved blood flow in the arteries but did not induce blood stasis in the veins. Our results suggest that the PGE₁ derivate might be a potential therapeutic agent, as it improved blood flow in the nerve roots in a canine model of chronic cauda equina compression.