STRUCTURAL BASES OF GASTROINTESTINAL MOTILITY CHANGES IN PARKINSON'S DISEASE: STUDY IN RATS.

BACKGROUND: Gastrointestinal disorders are frequently reported in patients with Parkinson's disease whose disorders reduce the absorption of nutrients and drugs, worsening the clinical condition of patients. However, the mechanisms involved in modifying gastrointestinal pathophysiology have not yet been fully explained. AIM: To evaluate its effects on gastrointestinal motility and the involvement of the vagal and splanchnic pathways. METHODS: Male Wistar rats (250-300 g, n = 84) were used and divided into two groups. Group I (6-OHDA) received an intrastriatal injection of 6-hydroxydopamine (21 µg/animal). Group II (control) received a saline solution (NaCl, 0.9%) under the same conditions. The study of gastric emptying, intestinal transit, gastric compliance and operations (vagotomy and splanchnotomy) were performed 14 days after inducing neurodegeneration. Test meal (phenol red 5% glucose) was used to assess the rate of gastric emptying and intestinal transit. RESULTS: Parkinson's disease delayed gastric emptying and intestinal transit at all time periods studied; however, changes in gastric compliance were not observed. The delay in gastric emptying was reversed by pretreatment with vagotomy and splanchnotomy+celiac gangliectomy, thus suggesting the involvement of such pathways in the observed motor disorders. CONCLUSION: Parkinson's disease compromises gastric emptying, as well as intestinal transit, but does not alter gastric compliance. The delay in gastric emptying was reversed by truncal vagotomy, splanchnotomy and celiac ganglionectomy, suggesting the involvement of such pathways in delaying gastric emptying.

Structural bases of gastrointestinal motility changes in parkinson's disease: study in rats / Bases estruturais das alterações da motilidade gastrintestinal na doença de parkinson: estudo em ratos

ABSTRACT Background: Gastrointestinal disorders are frequently reported in patients with Parkinson's disease whose disorders reduce the absorption of nutrients and drugs, worsening the clinical condition of patients. However, the mechanisms involved in modifying gastrointestinal pathophysiology have not yet been fully explained. Aim: To evaluate its effects on gastrointestinal motility and the involvement of the vagal and splanchnic pathways. Methods: Male Wistar rats (250-300 g, n = 84) were used and divided into two groups. Group I (6-OHDA) received an intrastriatal injection of 6-hydroxydopamine (21 µg/animal). Group II (control) received a saline solution (NaCl, 0.9%) under the same conditions. The study of gastric emptying, intestinal transit, gastric compliance and operations (vagotomy and splanchnotomy) were performed 14 days after inducing neurodegeneration. Test meal (phenol red 5% glucose) was used to assess the rate of gastric emptying and intestinal transit. Results: Parkinson's disease delayed gastric emptying and intestinal transit at all time periods studied; however, changes in gastric compliance were not observed. The delay in gastric emptying was reversed by pretreatment with vagotomy and splanchnotomy+celiac gangliectomy, thus suggesting the involvement of such pathways in the observed motor disorders. Conclusion: Parkinson's disease compromises gastric emptying, as well as intestinal transit, but does not alter gastric compliance. The delay in gastric emptying was reversed by truncal vagotomy, splanchnotomy and celiac ganglionectomy, suggesting the involvement of such pathways in delaying gastric emptying.

RESUMO Racional: Distúrbios gastrintestinais são frequentemente relatados em pacientes com doença de Parkinson cujos distúrbios reduzem a absorção de nutrientes e fármacos, agravando o quadro clínico dos pacientes. No entanto, os mecanismos envolvidos na alteração da fisiopatologia gastrintestinal ainda não foram totalmente elucidados. Objetivo: Avaliar os seus efeitos sobre a motilidade gastrintestinal e o envolvimento das vias vagal e esplâncnica. Métodos: Ratos Wistar machos (250-300 g, n=84) foram utilizados e divididos em dois grupos. O grupo I (6-OHDA) recebeu injeção intraestriatal de 6-hidroxidopamina (21 µg/animal). O grupo II (controle) recebeu solução salina (NaCl, 0,9%) nas mesmas condições. O estudo do esvaziamento gástrico, trânsito intestinal, complacência gástrica e operações (vagotomia e esplancnotomia) foram realizadas 14 dias após a indução da neurodegeneração. Refeição teste (vermelho de fenol+glicose 5%) foi utilizada para avaliar a taxa de esvaziamento gástrico e o trânsito intestinal. Resultados: A doença de Parkinson retardou o esvaziamento gástrico e o trânsito intestinal em todos os tempos estudados; porém, alterações da complacência gástrica não foram observadas. O retardo do esvaziamento gástrico foi revertido por pré-tratamento com vagotomia e esplancnotomia+gangliectomia celíaca, sugerindo assim, o envolvimento de tais vias nos distúrbios motores observados. Conclusão: A doença de Parkinson compromete o esvaziamento gástrico, bem como o trânsito intestinal, mas não altera a complacência gástrica. O retardo do esvaziamento gástrico foi revertido pela vagotomia troncular, esplancnotomia e gangliectomia celíaca, sugerindo o envolvimento de tais vias no retardo do esvaziamento gástrico.

EFFECT OF CHRONIC RENAL DYSFUNCTION ON THE PERMEABILITY OF THE COLON TO WATER AND ELECTROLYTES: EXPERIMENTAL STUDY IN RATS.

BACKGROUND: Renal insufficiency is a disease that affects several organs by provoking hypervolemia and uremia. The disease reaches more than 500 million people worldwide and few studies bring their influence on the gastrointestinal tract. AIM: To evaluate the influence of 5/6 nephrectomy-induced hypervolemia on colonic permeability to water and electrolytes. METHOD: Sixty male Wistar rats weighing between 280-300 g were divided into three groups: 3, 7 and 14 days after nephrectomy, each one having a false-operated/control and partially nephrectomized. For colonic permeability they were submitted to colonic perfusion with a solution of Tyroad containing phenolphthalein. Differences among the concentrations of Na+, K+ and Cl- were used to calculate the rate of colonic permeability for the electrolytes. Phenolphthalein concentrations were used to evaluate the rate of secretion and water absorption. RESULTS: The colonic secretion of water and electrolytes occurred expressively in the group seven days after nephrectomy. Hemodynamic and biochemical assessments determined the progression of renal failure in all three groups and polyethylene glycol was shown to be effective in reversing the secretory capacity of the colon. CONCLUSION: Hypervolemia established after 7 days post-nephrectomy 5/6 caused marked colonic secretion for water and electrolytes. The organism presents progressive colonic secretion as the blood volume increases; on the other hand, polyethylene glycol was able to revert this secretory framework of the colon to water and electrolytes by reversing the hypervolemia.

Effect of chronic renal dysfunction on the permeability of the colon to water and electrolytes: experimental study in rats / Efeito da disfunção renal crônica sobre a permeabilidade do cólon para água e eletrólitos: estudo experimental em ratos

ABSTRACT Background: Renal insufficiency is a disease that affects several organs by provoking hypervolemia and uremia. The disease reaches more than 500 million people worldwide and few studies bring their influence on the gastrointestinal tract. Aim: To evaluate the influence of 5/6 nephrectomy-induced hypervolemia on colonic permeability to water and electrolytes. Method: Sixty male Wistar rats weighing between 280-300 g were divided into three groups: 3, 7 and 14 days after nephrectomy, each one having a false-operated/control and partially nephrectomized. For colonic permeability they were submitted to colonic perfusion with a solution of Tyroad containing phenolphthalein. Differences among the concentrations of Na+, K+ and Cl- were used to calculate the rate of colonic permeability for the electrolytes. Phenolphthalein concentrations were used to evaluate the rate of secretion and water absorption. Results: The colonic secretion of water and electrolytes occurred expressively in the group seven days after nephrectomy. Hemodynamic and biochemical assessments determined the progression of renal failure in all three groups and polyethylene glycol was shown to be effective in reversing the secretory capacity of the colon. Conclusion: Hypervolemia established after 7 days post-nephrectomy 5/6 caused marked colonic secretion for water and electrolytes. The organism presents progressive colonic secretion as the blood volume increases; on the other hand, polyethylene glycol was able to revert this secretory framework of the colon to water and electrolytes by reversing the hypervolemia.

RESUMO Racional: A insuficiência renal é doença que afeta diversos órgãos por provocar hipervolemia e quadro urêmico ao organismo. A doença atinge mais de 500 milhões de pessoas em todo o mundo, e poucos estudos trazem sua influência sobre o trato gastrointestinal. Objetivo: Avaliar a influência da hipervolemia induzida pela nefrectomia 5/6 sobre a permeabilidade colônica para água e eletrólitos. Método: Foram utilizados 60 ratos machos Wistar, pesando entre 280-300 g divididos em três grupos: 3, 7 e 14 dias de pós-nefrectomia. Cada grupo foi formado por um controle e outro parcialmente nefrectomizado. Para os estudos de permeabilidade colônica, os animais foram submetidos à perfusão colônica com solução de Tyroad contendo fenolftaleína por 60 min. Diferenças entre as concentrações de Na+, K+, e Cl- foram utilizadas para calcular a taxa de permeabilidade colônica para os eletrólitos e as de fenolftaleína para avaliar a taxa de secreção e absorção de água. Resultados: A secreção colônica de água e eletrólitos ocorreu de forma expressiva no grupo 7 dias pós-nefrectomia. Avaliações hemodinâmicas e bioquímicas determinaram a evolução da insuficiência renal nos três grupos e o polietilenoglicol mostrou-se eficaz na reversão da capacidade secretora do cólon. Conclusão: O quadro de hipervolemia estabelecido a partir dos sete dias pós-nefrectomia 5/6 provocou acentuada secreção colônica para água e eletrólitos. O organismo apresenta secreção colônica progressiva a medida que aumenta a volemia sanguínea; por outro lado, o polietilenoglicol foi capaz de reverter esse quadro secretor do cólon para água e eletrólitos por reverter o quadro hipervolêmico.