Details

Autor(en) / Beteiligte

• WIESE, Ashley J
• RATHBUN, Michael
• LAPPI, Douglas A
• RUSSELL, Brian
• YAKSH, Tony L
• BUTT, Mark T
• MALKMUS, Shelle A
• RICHTER, Philip J
• OSBORN, Kent G
• QINGHAO XU
• VEESART, Samantha L
• STEINAUER, Joanne J
• HIGGINS, Denise

Titel

Intrathecal Substance P-Saporin in the Dog: Distribution, Safety, and Spinal Neurokinin-1 Receptor Ablation

Ist Teil von

• Anesthesiology (Philadelphia), 2013-11, Vol.119 (5), p.1163-1177

Ort / Verlag

Hagerstown, MD: Lippincott Williams & Wilkins

Erscheinungsjahr

2013

Quelle

MEDLINE

Beschreibungen/Notizen

• Neurokinin-1 receptors (NK1-rs) located on superficial dorsal horn neurons are essential for integration of nociceptive input. Intrathecal injection of substance P-saporin (SP-SAP) leads to local loss of spinal NK1-r (+) neurons suggesting its potential as a therapeutic agent for chronic pain. The authors determined, in a canine model, effects of lumbar intrathecal SP-SAP. Distribution of SP-SAP and Saporin was determined in plasma, lumbar cerebrospinal fluid, and tissue. Safety of intrathecal SP-SAP was determined in four groups (six dogs each) administered 0 (0.9% saline), 1.5, 15, or 150 µg SP-SAP through lumbar intrathecal catheters. Behavioral, physiologic, and biochemical variables were assessed. Spinal tissues were collected at 7 and approximately 90 days, or earlier if significant morbidity developed, and analyzed for NK1-r (+) neuron loss and histopathology. SP-SAP and Saporin were detectable in lumbar cerebrospinal fluid for up to 4 and 24 h, respectively. Animals receiving intrathecal saline, 1.5, or 15 µg of SP-SAP showed no persistent neurologic deficits. Three animals receiving 150 µg of SP-SAP developed pelvic limb paraparesis and were euthanized prematurely. Immunohistochemistry and in situ hybridization cell counts confirmed a significant reduction in NK1-r (+) in superficial dorsal horn neurons from lumbar spinal cord after intrathecal administration of 15 and 150 µg of SP-SAP. A significant loss of NK1-r neurons in the lumbar ventral horn occurred only with 150-µg SP-SAP. Intrathecal 15-µg SP-SAP reduced dorsal, but not ventral, NK1-r (+) neurons at the spinal level of delivery with minimal side effects, whereas 150-µg SP-SAP resulted in motor neuron toxicity.