Papel do nervo renal na isquemia e reperfusão renal aguda em ratos
Data
2022-10-07
Autores
Marreiros, Ana Caroline [UNIFESP]
Orientadores
Campos Junior, Ruy Ribeiro de [UNIFESP]
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Estudos anteriores demonstram que a isquemia e reperfusão (IR) pode ocorrer
em algumas condições fisiopatológicas e procedimentos cirúrgicos. A lesão por
IR é uma das principais causas de complicações clínicas, porém não há um
tratamento padronizado. Os rins possuem vasta inervação aferente e eferente,
foi sugerido em estudos anteriores que a atividade nervosa simpática renal está
aumentada após a IR, alguns acreditam que a neuroinflamação possa contribuir
para ativação simpática sustentada. O presente estudo teve como objetivo
avaliar a participação das fibras aferentes renais na IR. Todos os experimentos
foram aprovados pelo CEUA da UNIFESP (n:1567290421). Dois grupos de ratos
Wistar (peso entre 150 e 180 gramas) foram utilizados divididos: 1) Grupo
Controle (n =8); 2) Grupo deaferentado renal (n=6). A IR foi induzida pela
obstrução total do fluxo sanguíneo para o rim esquerdo por um pinçamento da
artéria renal durante 60 min, seguido de reperfusão por 120 min. Parâmetros
cardiovasculares e de atividade nervosa vasomotora simpática renal (ANSr) e
esplâncnica (ANSe) foram registrados, além de coleta de sangue da artéria
femoral em dois tempos, antes da isquemia e após 120 min de reperfusão com
objetivo de realizar a contagem total e diferencial das populações de leucócitos.
A isquemia renal aumentou a ANSr (20 min: 0,07 ± 0,04* ΔUA), tal aumento pode
ser explicado pelo acionamento das fibras aferentes uma vez que a retirada
seletiva das aferências renais promoveu simpatoinibição para o território renal
durante a IR (180 min: -73 ± 32* Δspikes/s), assim como queda da PAM e
bradicardia mais expressiva que o grupo controle, porém não houve alterações
na ANSe, reforçando a importância da ANSr para manutenção da PA. Quanto a
contagem de leucócitos não foram observadas diferenças significativas entre os
grupos, somente um aumento importante nas populações de neutrófilos e
diminuição de linfócitos após a reperfusão em ambos os grupos, ou seja, a
inflamação está presente em ambos os grupos, porém é necessário a aferência
para passagem do estímulo. Os resultados mostram que aferentes renais são
fundamentais para a resposta simpatoexcitatória preferencial para o território
renal durante a IR aguda.
Further studies and surgical procedures. Injury due to the main causes there is no treatment for complications, but for the main causes. The rinses have vast inferences in favor of previous studies that the renal sympathetic nerve activity is increased after IR, may contribute to the neuroinflammation being compatible with sympathetic neuroinflammation. The present study aimed to evaluate the participation of the afferent fibers in the RI. All experiments were approved by the CEUA of UNIFESP (n:1567290421). Two groups of Wistar rats (weight between 150 and 180 grams) were used: 1) Control Group (n =8); 2) Renal deafferentate group (n=6). IR was induced by total obstruction of blood flow to the left by renal darim clamping for 60 min, followed by reperfusion for 120 min. Cardiomyopathies and renal sympathetic vasomotor (rSNA) and splanchnic (sSNA) activity were recorded, in addition to femoral arterial blood collection in two, before ischemia and after 120 min of reperfusion in order to perform the total count and the timing of leukocyte populations. Renal ischemia increased rSNA (20 min: 0.07 ± 0.04* ΔUA), such increase can be explained by the activation of fibers during afferents, since the selective selection of renal afferents promoted sympathoinization to the renal territory at IR ( 180 min: -73 ± 32* Δspikes/s), as well as the decrease in MAP and more expressive bradycardia than the control, but there were no changes in sSNA, reinforcing the importance of rSNA for BP maintenance. As for the leukocyte count, no significant differences were observed between the groups, only an important difference in the populations of neutrophils and lymphocytes after reperfusion in both groups, that is, inflammation is in both groups, but it is necessary for both to have an afference for stimulus passage. The results of the preferential phase show that renal afferents are fundamental for the renal sympathoexcitatory response during the IR territory.
Further studies and surgical procedures. Injury due to the main causes there is no treatment for complications, but for the main causes. The rinses have vast inferences in favor of previous studies that the renal sympathetic nerve activity is increased after IR, may contribute to the neuroinflammation being compatible with sympathetic neuroinflammation. The present study aimed to evaluate the participation of the afferent fibers in the RI. All experiments were approved by the CEUA of UNIFESP (n:1567290421). Two groups of Wistar rats (weight between 150 and 180 grams) were used: 1) Control Group (n =8); 2) Renal deafferentate group (n=6). IR was induced by total obstruction of blood flow to the left by renal darim clamping for 60 min, followed by reperfusion for 120 min. Cardiomyopathies and renal sympathetic vasomotor (rSNA) and splanchnic (sSNA) activity were recorded, in addition to femoral arterial blood collection in two, before ischemia and after 120 min of reperfusion in order to perform the total count and the timing of leukocyte populations. Renal ischemia increased rSNA (20 min: 0.07 ± 0.04* ΔUA), such increase can be explained by the activation of fibers during afferents, since the selective selection of renal afferents promoted sympathoinization to the renal territory at IR ( 180 min: -73 ± 32* Δspikes/s), as well as the decrease in MAP and more expressive bradycardia than the control, but there were no changes in sSNA, reinforcing the importance of rSNA for BP maintenance. As for the leukocyte count, no significant differences were observed between the groups, only an important difference in the populations of neutrophils and lymphocytes after reperfusion in both groups, that is, inflammation is in both groups, but it is necessary for both to have an afference for stimulus passage. The results of the preferential phase show that renal afferents are fundamental for the renal sympathoexcitatory response during the IR territory.