Ultraviolet irradiation of cerebrospinal fluid stimulates compensatory processes in cats with a unilaterally damaged central nervous system

Abstract

Portions of cerebrospinal fluid (CSF) withdrawn from cats operated upon for unilateral removal of the motor neocortex were exposed to ultraviolet (UV) radiation and then returned to the cats to e~aluate the effects of irradiation on the recovery of voluntary movements by the affected limb and the activity of CSF peptide and protein neurohumoral factors durin~ tilt. i~o>toperative period. The exposure of CSF to UV radiation substantially acceleratcd ~,,rnpensatory processes (the recovery of motor functions) in the animals and activated t~',~, t~,,~y'nthesis of neurohumoral factors. Key Words: central m,r~,,,.~ ~vstem; ultraviolet radiation; cerebrospinal fluid; motor disordersAs demonstrated in numerous studies, p~'pttdc tactots displaying lateral tropism to moto: ct'v, tcrs of the spinal cord and activating their actl~zt~ appear in the central nervous system early in ttw c(v.~rsc of compensatory processes that develop attcr unilateral injuries to the motor analyzer [31 Sub~t.qtwntly these factors lose their activity by forming" cort:picxes with the emerging high-molecular protet:', factors (binding factors), some of which arc immtir:o~,lobulins [4]. Attempts to stimulate compensatt,~ processes by administering peptide factors or ~mmu-nomodulators during the acute posttraumatic period have produced encouraging results 15.71. Continuing the quest for agents capable of stimulatin~ compensatory processes should undoubtedly be on the list of research priorities.In this study, cerebrospinal fluid (CSF) withdrawn from cats operated upon for unilateral removal of the motor neocortex was exposed to ultraviolet (UV) radiation and then returned to the cats to evaluate the effects of CSF irradiation on the recovery of voluntary movements by the affect- MATERIALS AND METHODSIn 9 male cats, the cortical representation of the right hind limb (motor neocortex) was removed as previously described [1], after which CSF was collected from an occipital cistern (approximately 0.5 ml per kg body weight) and exposed for 2 rain to UV radiation predominantly of 254 nm in a quartz cuvette 10 cm-' in area, the radiation flux density being 2 mW/cm2; the CSF was then returned to the animal. The irradiation procedure was repeated on postoperative days 3, 5, and 8. The control group consisted of 6 male cats that differed from the test animals only in that their CSF was not irradiated after being placed in a cuvette for 2 min. In both groups, CSF samples were taken from the occipital cistern on days 3,5,8, 11, 14, 17, and 21 to determine the activity of peptide and protein factors. In view of the species nonspecificity of the neurohumoral factors under study [2], CSF from operated cats was tested for its ability to induce postural asymmetry in recipient rats before and after heat