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

<p>Abstract</p> <p>Background</p> <p>Reduction of blood flow is important in the induction of neurogenic intermittent claudication (NIC) in lumbar spinal canal stenosis. PGE₁improves the mean walking distance in patients with NIC type cauda equina compression. PGE₁derivate 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 PGE₁derivate has vasodilatory effects on both arteries and veins in a canine model of chronic cauda equina compression.</p> <p>Methods</p> <p>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 E₁derivate) 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 PGE₁derivate.</p> <p>Results</p> <p>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 PGE₁derivate (p < 0.05). Blood flow velocity did not change over 90 minutes in either the arteries or veins.</p> <p>Discussion</p> <p>The PGE₁derivate improved blood flow in the arteries but did not induce blood stasis in the veins. Our results suggest that the PGE₁derivate might be a potential therapeutic agent, as it improved blood flow in the nerve roots in a canine model of chronic cauda equina compression.</p

An immunohistochemical study of the antinociceptive effect of calcitonin in ovariectomized rats

<p>Abstract</p> <p>Background</p> <p>Calcitonin is used as a treatment to reduce the blood calcium concentration in hypercalcemia and to improve bone mass in osteoporosis. An analgesic effect of calcitonin has been observed and reported in clinical situations. Ovariectomaized (OVX) rats exhibit the same hormonal changes as observed in humans with osteoporosis and are an animal model of postmenopousal osteoporosis. The aim of this study to investigate antinociceptive effect of calcitonin in OVX rats using the immunohistochemical study.</p> <p>Methods</p> <p>We assessed the antinociceptive effects of calcitonin in an ovariectomized (OVX) rat model, which exhibit osteoporosis and hyperalgesia, using the immunohistochemical method. Fifteen rats were ovariectomized bilaterally, and ten rats were received the same surgery expected for ovariectomy as a sham model. We used five groups: the OVX-CT (n = 5), the sham-CT (n = 5), and the OVX-CT-pcpa (n = 5) groups recieved calcitonin (CT: 4 U/kg/day), while OVX-vehi (n = 5) and the sham-vehi (n = 5) groups received vehicle subcutaneously 5 times a week for 4 weeks. The OVX-CT-pcpa-group was given traperitoneal injection of p-chlorophenylalanine (pcpa; an inhibitor of serotonin biosynthesis) (100 mg/kg/day) in the last 3 days of calcitonon injection. Two hours after 5% formalin (0.05 ml) subcutaneously into the hind paw, the L5 spinal cord were removed and the number of Fos-immunoreactive (ir) neurons were evaluated using the Mann-Whitney-U test.</p> <p>Results</p> <p>The numbers of Fos-ir neurons in the OVX-CT and sham-CT groups were significantly less than in the OVX-vehi and sham-vehi groups, respectively (p = 0.0090, p = 0.0090). The number of Fos-ir neurons in the OVX-CT-pcpa-group was significantly more than that of the OVX-CT-group (p = 0.0283), which means pcpa inhibits calcitonin induced reduction of c-Fos production.</p> <p>Conclusion</p> <p>The results in this study demonstrated that 1) the increase of c-Fos might be related to hyperalgesia in OVX-rats. 2) Calcitonin has an antinociceptive effect in both OVX and sham rats. 3) The central serotonergic system is involved in the antinociceptive properties of calcitonin.</p

Vasodilative effects of prostaglandin Ederivate on arteries of nerve roots in a canine model of a chronically compressed cauda equina-1

<p><b>Copyright information:</b></p><p>Taken from "Vasodilative effects of prostaglandin Ederivate on arteries of nerve roots in a canine model of a chronically compressed cauda equina"</p><p>http://www.biomedcentral.com/1471-2474/9/41</p><p>BMC Musculoskeletal Disorders 2008;9():41-41.</p><p>Published online 8 Apr 2008</p><p>PMCID:PMC2358890.</p><p></p

Vasodilative effects of prostaglandin Ederivate on arteries of nerve roots in a canine model of a chronically compressed cauda equina-3

6α-CD (p < 0.05).<p><b>Copyright information:</b></p><p>Taken from "Vasodilative effects of prostaglandin Ederivate on arteries of nerve roots in a canine model of a chronically compressed cauda equina"</p><p>http://www.biomedcentral.com/1471-2474/9/41</p><p>BMC Musculoskeletal Disorders 2008;9():41-41.</p><p>Published online 8 Apr 2008</p><p>PMCID:PMC2358890.</p><p></p

Vasodilative effects of prostaglandin Ederivate on arteries of nerve roots in a canine model of a chronically compressed cauda equina-0

6α-CD (p < 0.05).<p><b>Copyright information:</b></p><p>Taken from "Vasodilative effects of prostaglandin Ederivate on arteries of nerve roots in a canine model of a chronically compressed cauda equina"</p><p>http://www.biomedcentral.com/1471-2474/9/41</p><p>BMC Musculoskeletal Disorders 2008;9():41-41.</p><p>Published online 8 Apr 2008</p><p>PMCID:PMC2358890.</p><p></p