Study of Correction of Somatic Pain under the Conditions of Experimental Pathology of Multiple Sclerosis

The purpose of the study was to experimentally substantiate the ways of pharmacological correction of somatic pain syndrome in conditions of the experimental equivalent of multiple sclerosis through a comparative system analysis and the use of complex methodological approaches. Materials and methods. To study multiple sclerosis, we used an experimental model with autoimmune mechanisms of inflammatory demyelination – a model of experimental allergic encephalomyelitis. To assess the antinociceptive activity of painkillers, we used the method of electrical stimulation of the rats’ tail root. The activity of the enzyme prostaglandin H-synthetase was also determined. Results and discussion. A comparative analysis of the analgesic activity indicators of combinations of methylprednisolone with analgesics under the condition of the formed experimental allergic encephalomyelitis showed that their antinociceptive potential (taking into account the basic therapy with methylprednisolone) decreased in the series meloxicam > lornoxicam ≈ ketorolac ≈ paracetamol > celecofenacoxib ≈ sodium diclofupene ≈ diclofupene ≈ diclofupene. Accordingly, the maximum effect on the threshold of nociception under these experimental conditions was exerted by meloxicam and lornoxicam. The combined administration of methylprednisolone with diclofenac sodium, celecoxib and meloxicam reduced the activity of prostaglandin N-synthetase in the brain structures by 49.8% (p <0.05), 50.4% (p <0.05) and 51% (p <0.05), respectively, compared with the indicators of the control group. The same drugs markedly reduced the activity of prostaglandin N-synthetase in the spinal cord by 23.9% (p <0.05) (Methylprednisolone + diclofenac), by 34% (p <0.05) (Methylprednisolone + celecoxib) and by 47.4% (p <0.05) (Methylprednisolone + meloxicam) compared with the control group. Our analysis of the analgesic activity of antidepressants and anticonvulsants as means of correcting nociceptive pain in experimental allergic encephalomyelitis found that their antinociceptive potential was inferior to the severity of the analgesic effect of nonsteroidal anti-inflammatory drugs. Conclusion. Among the studied non-steroidal anti-inflammatory drugs, antidepressants and anticonvulsants, the maximum therapeutic efficacy as a means of correcting nociceptive pain in experimental allergic encephalomyelitis against the background of basic methylprednisolone therapy was shown by meloxicam, which gives grounds to recommend it as the analgesic of choice for eliminating somatic pain syndromes

Efficiency of Experimental Allergic Encephalomyelitis Modeling as an Experimental Model of Multiple Sclerosis

The purpose of the study was the most adequate modeling of multiple sclerosis in the form of autoimmune allergic encephalomyelitis for further use in the study of experimental equivalents of neurodegenerative conditions. Materials and methods. The article highlights the results of the formation of experimental allergic encephalomyelitis, for the induction of which homologous brain homogenates were used, which in terms of encephalitogenicity ranks first among other drugs (homologous, heterogeneous brain and spinal cord homogenates). An encephalitogenic mixture was injected into the connective tissue of the base of the animal's tail at the rate of 0.1 ml per 100 g of body weight. Results and discussion. Experimental allergic encephalomyelitis reproducible by intradermal administration of a homogenate of the brain, spinal cord and peripheral nerves with a Freund's stimulator belongs to a true autoimmune disease of the nervous system and is an experimentally reproducible model of multiple sclerosis. According to the experimental data obtained, the state of the animals showed that the rats of the experimental group lost body weight, had a number of pathological neurological symptoms, which manifested on average from 10-12 days. The increase in symptoms continued for an average of 7 days and was not very stable. Experimental animals had paresis, manifestations of ataxia, walking disorders and urinary and fecal incontinence, lethargy, which corresponded to 1-2 degrees of the rating scale in 13 animals. In 7 rats, paresis of the hind limbs and loss of tail tone were expressed (grade 3). Most of the rats recovered spontaneously within 6-8 days after the onset of clinical manifestations (18-20 days after immunization). According to the requirements of the experiment, during the paralytic stage, the rats had free access to food and water. In addition, our experimental studies on the formation of experimental allergic encephalomyelitis were confirmed morphologically using electron microscopy. Conclusion. The use of this technique for the formation of experimental allergic encephalomyelitis made it possible to obtain a simulated pathological state of multiple sclerosis in the form of experimental allergic encephalomyelitis and can be used in further studies to identify the corresponding patterns, the degree and nature of changes in the immune and nervous systems of the body during the reproduction of an experimental pathological state. The data obtained can serve as a basis for further studies of drugs and their combinations in order to improve and rationalize the pharmacotherapy of multiple sclerosis