Quercetin as a nephroprotector after warm ischemia: histomorphometric evaluation in a rodent model

ABSTRACT Purpose: To quantitatively evaluate the possible long-term protective effects of quercetin during renal warm ischemia. Materials and Methods: Male rats were allocated into 4 groups: sham (S), sham quercetin (SQ), ischemia (I), and ischemia quercetin (IQ). Groups SQ and IQ received quercetin (50mg/kg) before and after surgery. Groups I and IQ had their left renal vessels clamped for 60 minutes. All animals were euthanized four weeks after the procedure, and serum urea and creatinine levels were measured. Renal weight and volume, cortex-non-cortex area ratio (C-NC), cortical volume (CV), glomerular volumetric density (Vv[glom]), volume-weighted glomerular volume (VWGV) and number of glomeruli per kidney (N[glom]) were evaluated by stereological methods. Results were considered statistically significant when p <0.05. Results: Serum urea levels in group I increased by 10.4% in relation to group S, but no differences were observed among the other groups. The C-NC of group I was lower than those of all other groups, and group IQ had similar results to sham groups. The Vv[glom] and N[glom] of group I were lower than those of group S (33.7% and 28.3%, respectively) and group IQ had no significant difference compared to the S group. Conclusions: Quercetin was effective as a nephroprotective agent in preventing the glomerular loss observed when the kidney was subjected to warm ischemia. This suggests that this flavonoid may be used preventively in kidney surgery, when warm ischemia is necessary, such as partial nephrectomy.

Anatomical background of ovine kidney for use as animal model: analysis of arterial segmentation, proportional volume of each segment and arterial injury after cranial pole partial nephrectomy

ABSTRACT Objective To study the arterial segments of ovine kidney, present a proportional volume analysis of each kidney arterial segment, and analyze arterial injuries caused by simulated partial nephrectomy of cranial pole. Materials and Methods Forty-eight ovine kidneys injected with polyester resin into the renal arteries and collecting system were used in this study. Eighteen kidneys were used to study the arterial segments and the proportional volume of each renal segment. Other 30 kidneys were submitted to superior pole resection at a distance of 1.0cm, 0.5cm, or exactly at the cranial hilar edge, just before the resin hardening. These endocasts were used to evaluate the arterial injuries caused by these different resection planes. Results Ovine renal artery divided into two (ventral and dorsal) or three segmental arteries. Dorsal segment presented higher proportional volume than ventral segment. For kidneys with three segments, the third segment was on the caudal region (caudo-ventral or caudo-dorsal segment) and presented the lowest proportional volume. None of the resected kidneys (at 1.0, 0.5 or at the cranial hilar edge) presented injury of arterial branches that irrigate non-resected region. Conclusion The segmental distribution of renal artery, the proportional volume of each segment and arterial injuries after cranial pole resection in ovine kidneys are different from what is observed in human kidneys. Meanwhile, ovine kidneys show a primary segmental division on anterior and posterior, as in humans, but different from swine. These anatomical characteristics should be considered when using ovine as animal models for renal experimental and/or training procedures.

Stereological study of the elastic fiber and smooth muscle cell system in the bovine and buffalo penis / Estereologia do sistema elástico e das células musculares lisas no pênis fibroelástico zebuino e bubalino

Samples of ten penises of Mediterranean buffaloes and ten penises of Red Sindhi cattle were used. The thickness of the tunica albuginea (TA), distribution of smooth muscle cells (SMC) and volume density (Vv) of elastic system fibers in TA, corpus cavernosum (CC) and corpus spongiosum (CS) were evaluated. The Vv of elastic system fibers in buffalo and bovine penis was respectively 4.07% ±0.88% and 3.36% ±1.21% in TA; 17.32% ±2.21% and 13.14% ±1.27% (CC), 26.58% ±4.31% and 31.36% ±3.67% (CS). The CC of buffalo presented higher Vv of elastic fibers than bovine, while in the CS the Vv of elastic fibers in buffaloes was smaller than in cattle. The TA thickness showed a significant difference among the species studied. The arrangement of SMC in the bovine penises and in the water buffalo suggests that this pattern is common to animals that have fibroelastic penises.

O pênis dos zebuinos e bubalinos são classificados como do tipo fibroelástico, sendo grande parte de sua rigidez conferida pelas fibras colágenas e elásticas presentes na matriz extracelular. Embora alguns estudos tenham abordado estes componentes em bovinos europeus, os dados na literatura sobre zebuínos e bubalinos são escassos. Nós avaliamos a espessura da túnica albugínea, a distribuição das células musculares lisas e a densidade volumétrica (Vv) das fibras do sistema elásticona túnica albugínea, no corpo cavernoso e esponjoso do pênis de animais jovens adultos inteiros.Foram utilizados 10 fragmentos de pênis de búfalos da raça Mediterrâneo e 10 fragmentos de pênis de bovinos da raça Red Sindi. Os fragmentos de pênis foram processados de acordo com a técnica histológica de rotina para inclusão em parafina e corados pela Fucsina Resorcina de Weigert, Picro Sirius Red, Tricrômio de Gomori e anticorpo anti α actina. As fibras elásticas foram determinadas em 25 campos aleatórios de cada fragmento, utilizando o sistema teste modelo M42. A Vv das fibras do sistema elástico no pênis do búfalo e bovino foram(média e desvio padrão respectivamente) de 4,07% ±0,88 e 3,36% ±1,21 na túnica albugínea; 17,32% ±2,21 e 13,14% ±1,27 no corpo cavernoso; 26,58% ±4,31 e 31,36% ±3,67 no corpo esponjoso, respectivamente. Houve diferença na Vv das fibras elásticas entre as duas espécies, no corpo cavernoso e no corpo esponjoso. Na espessura da túnica albugínea houve diferença significativa entre o búfalo Mediterrâneo (1,4mm ±0,11) e o bovino Red Sindi (1,76mm ±0,23). Nas duas espécies, as fibras musculares lisas foram encontradas apenas associadas ao endotélio de revestimento dos seios cavernosos. Com base nestes resultados, podemos concluir que existem diferenças na proporção entre os componentes da matriz extracelular nas espécies estudadas, fato que deve ser considerado nos procedimentos clínicos e cirúrgicos veterinários e continua a ser investigado.

Does prolonged pneumoperitoneum affect the kidney? Oxidative stress, stereological and electron microscopy study in a rat model

Purpose: Pneumoperitoneum (Pp) at 12 to 15 mmHg in rats is associated with kidney damage. However, Pp at 8 mmHg is now known to best correlate to working pressures used in humans. Thus the aim of this work was to study the kidney of rats submitted to prolonged Pp at 8 mmHg. Materials and Methods: Rats were divided into a Sham group (n = 14), submitted to anesthesia, and a Pp group (n = 14), submitted to Pp at 8 mmHg, followed by deflation. In both groups, 7 animals were immediately killed and their kidneys were used for oxidative stress analyses. The remaining 7 rats in each group were evaluated after 6 weeks for the number of glomeruli and podocyte morphology. Results: For all analyzed parameters Sham and Pp groups presented no statistical difference. Conclusion: When submitted to adequate Pp pressures (8 mmHg), no kidney damage occurs in rats. .