The effects of intra-cerebroventricular administered rocuronium on the central nervous system of rats and determination of its epileptic seizure-inducing dose / Efeitos da administração intracerebroventricular de rocurônio sobre o sistema nervoso central de ratos e determinação da dose indutora de crise epiléptica

Abstract Background: The aim of this study was to investigate the effects of intracerebroventricularly administered rocuronium bromide on the central nervous system, determine the seizure threshold dose of rocuronium bromide in rats, and investigate the effects of rocuronium on the central nervous system at 1/5, 1/10, and 1/100 dilutions of the determined seizure threshold dose. Methods: A permanent cannula was placed in the lateral cerebral ventricle of the animals. The study was designed in two phases. In the first phase, the seizure threshold dose of rocuronium bromide was determined. In the second phase, Group R 1/5 (n = 6), Group 1/10 (n = 6), and Group 1/100 (n = 6) were formed using doses of 1/5, 1/10, and 1/100, respectively, of the obtained rocuronium bromide seizure threshold dose. Results: The rocuronium bromide seizure threshold value was found to be 0.056 ± 0.009 µmoL. The seizure threshold, as a function of the body weight of rats, was calculated as 0.286 µmoL/kg-1. A dose of 1/5 of the seizure threshold dose primarily caused splayed limbs, posturing, and tremors of the entire body, whereas the dose of 1/10 of the seizure threshold dose caused agitation and shivering. A dose of 1/100 of the seizure threshold dose was associated with decreased locomotor activity. Conclusions: This study showed that rocuronium bromide has dose-related deleterious effects on the central nervous system and can produce dose-dependent excitatory effects and seizures.

Resumo Justificativa: O objetivo deste estudo foi investigar os efeitos do brometo de rocurônio administrado intracerebroventricularmente sobre o sistema nervoso central, determinar a dose do limiar convulsivo de rocurônio em ratos e investigar os efeitos de rocurônio no sistema nervoso central em diluições de 1/5, 1/10 e 1/100 da dose do limiar convulsivo determinada. Métodos: Uma cânula permanente foi colocada no ventrículo lateral do cérebro dos animais. O estudo foi projetado em duas fases. Na primeira, a dose do limiar convulsivo do brometo de rocurônio foi determinada. Na segunda, o Grupo R 1/5 (n = 6), o Grupo 1/10 (n = 6) e Grupo 1/100 (n = 6) foram formados com doses de 1/5, 1/10 e 1/100, respectivamente, da dose do limiar convulsivo de brometo de rocurônio obtida. Resultados: Descobrimos que o valor do limiar convulsivo de brometo de rocurônio é 0,056 ± 0,009 µmoL. O limiar convulsivo, como uma função do peso corporal dos ratos, foi calculado como 0,286 µmoL/kg-1. Uma dose de 1/5 da dose do limiar convulsivo causou principalmente abertura postural dos membros e tremores em todo o corpo, enquanto uma dose de 1/10 da dose do limiar convulsivo causou agitação e tremores. Uma dose de 1/100 da dose do limiar convulsivo foi associada à diminuição da atividade locomotora. Conclusões: Este estudo mostrou que o brometo de rocurônio tem efeitos deletérios relacionados com a dose sobre o sistema nervoso central e pode produzir efeitos excitatórios dependentes da dose e convulsões.

Suprachoroidal drainage of aqueous humour with a novel implant: Suprajet / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To evaluate the efficacy and safety of a new implant, Suprajet ( VSY Biotechnology, Istanbul, Turkey ) , which is developed for supraciliary and suprachoroidal drainage of aqueous humour. ·METHODS: Five rabbits were included in the study. One Suprajet shunt was implanted in one eye of each rabbit. Implantation was performed by a superior clear corneal incision through the anterior chamber into the suprachoroidal space. Proximal end of the implant was placed in the iris root resting against the scleral spur, distal end was placed in the suprachoroidal space. Rabbits were followed for 4wk. Preoperative and postoperative intraocular pressure ( IOP ) levels were measured with Tonopen AVIA. At last follow-up visit animals were sacrificed and eyes were enucleated. Macroscopic and histopathologic evaluation of the eyes were made. ·RESULTS:Mean preoperative IOP was 18. 6±6. 1 mmHg. Mean postoperative IOP was 8. 4 ± 1. 1 mmHg, at one week. At the 2nd week of the follow-up period one rabbit died. Thereafter, only 4 rabbits were followed. Mean postoperative IOP was 11. 0 ± 2. 8 mmHg at the 2nd week, 9. 50±3. 1 mmHg at the 3rd week and 11. 3 ±3. 3 mmHg at 4th week after the operation. When mean preoperative IOP was compared with the postoperative IOP values, only the IOP at the first week was found as significantly lower ( P=0. 042). There was no statistically significant difference between mean preoperative IOP level and mean IOP level at 2, 3 and 4wk postoperatively (P=0. 66, P=0. 66 and P=0. 102, respectively). As an intraoperative complication, minimal hyphema was noted in three eyes during the surgery. However, the next day hyphema cleared completely. Macroscopic evaluation of the enucleated material showed that in one eye the distal end of the implant was in the vitreous instead of suprachoroidal space, in the other 3 eyes the distal end of the implant was noted in the suprachoroidal space. In all eyes, proximal end of the implant was localized in the anterior chamber angle. Histopathologic evaluation of the enucleated eyes showed deposition of irregular collagen bundles and fibroplasia including numerous fibroblastic and histiocytic cells around the implant. ·CONCLUSION: This preliminary animal study showed that implantation of Suprajet in glaucoma is a promising procedure. Further studies are needed to evaluate its efficacy and safety profile.