title: Studies on the permeability of potassium ions across the dura and arachnoid mater of the rat spinal cord.
abstract: A combined impounder-surface K+ electrode was developed to measure change in K+ ion concentration of the cerebrospinal fluid (CSF) across the dura and arachnoid maters. To determine whether K+ permeability of the rat dura and arachnoid maters is due to an intrinsic permeability, a study was conducted using an atraumatic laminectomy model. Dorsal laminectomy was performed at T7-8, T12, and L1. Artificial CSF containing 4.2 mM, 24.2 mM, or 54.2 mM of K+ was administered by anterograde subdural infusion into the subarachnoid space from the proximal laminectomy site (T7-8), with effluent overflow at the distal laminectomy site (L1). K+ concentration on the dorsal aspect of the central laminectomy site (T12) was measured. It was found that changes in K+ concentrations of the infused solution were detected by the epidural surface electrode. This suggests that the intact rat spinal cord dura and arachnoid maters may be permeable to K+ in this laminectomy model. This study supports the use of the combined impounder-K+ electrode for measuring changes in K+ ion concentration of the CSF that can result from spinal cord trauma and ischemia.
authors.affiliation: Section of Surgery, Veterinary Hospital of the University of Pennsylvania VHUP, School of Veterinary Medicine, Philadelphia.
authors.forename: K K
authors.initials: KK
authors.lastname: Sadanaga
authors.forename: S T
authors.initials: ST
authors.lastname: Ohnishi
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism; D000818:Animals; D001099:Arachnoid / Q000033:anatomy & histology / Q000378:metabolism*; D004396:Coloring Agents; D004388:Dura Mater / Q000033:anatomy & histology / Q000378:metabolism*; D004566:Electrodes; D007268:Injections, Epidural; D008297:Male; D010477:Perfusion; D010539:Permeability; D011188:Potassium / Q000134:cerebrospinal fluid / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013116:Spinal Cord / Q000033:anatomy & histology / Q000378:metabolism*; D013346:Subarachnoid Space / Q000033:anatomy & histology / Q000378:metabolism
chemical_list: D004396:Coloring Agents; D011188:Potassium