N-Domain angiotensin I-converting enzyme expression in renal artery of Wistar, Wistar Kyoto, and spontaneously hypertensive rats.

One of the most intriguing features in kidney transplantation is the finding that kidneys from hypertensive rats can transfer arterial hypertension on transplantation into normotensive rats. Some evidence also suggest that, in humans undergoing renal transplantation, the genotype of the donor kidney determines the blood pressure in the recipient. The renin-angiotensin-aldosterone system is the major etiological candidate in hypertension because it plays an important role in the control of cardiovascular homeostasis. Angiotensin-converting enzyme (ACE) cleaves the C-terminal from angiotensin I as well as from bradykinin. Thus, by generating the potent vasoconstrictor angiotensin II and by degrading the vasodepressor bradykinin, ACE is considered to play a role in blood pressure regulation. We have previously described the presence of N-domain ACE in urine of Wistar (W), Wistar Kyoto (WKY), and spontaneously hypertensive rats (SHR), all of which can hydrolyze the vasodilator peptide Angiotensin 1-7 and also the N-Acetyl-Ser-Asp-Lys-Pro, two peptides described as specific for N-domain ACE. These findings suggest that the 90 kd ACE isoform found in urine and in tissues of SHR is a possible genetic marker of hypertension. Based on the fact that the renal artery has an important role in the control of renal blood flow, we evaluated the presence of N-domain ACE in the renal artery of hypertensive and normotensive rats. Using Western blotting techniques on the renal arteries of W and WKY rats, we detected the 190-kd ACE (similar to somatic ACE) and also the 65-kd ACE previously described in urine and renal tissue as N-domain ACE. The 65-kd and 90-kd isoforms of ACE were also detected in renal arteries in SHR rats. Further studies are required to understand the role of 90-kd enzyme described as a possible local marker of hypertension, its contribution in angiotensin catabolism, and whether this abnormal form of the enzyme has any link with the development and transfer of hypertension after transplantation.

Evaluation of equine corneal endothelium after exposure to 0. 05% brilliant blue - an in vitro study / Avaliação do endotélio corneano de equinos após contato com o corante azul brilhante 0, 05% - estudo in vitro

The aim of this study was to evaluate the immediate effects of 0.05% brilliant blue on corneal endothelium of horses. Thirty-eight corneas of 19 horses, male or female, of different ages were studied. Corneas were randomly divided into two groups. Group 1: Corneal endothelium was covered with 0.3mL of brilliant blue 0.05% for 60 seconds followed by rinsing with a balanced salt solution. Group 2: Corneal endothelium was covered with BSS for 60 seconds. The corneas were excised with an 8mm trephine and prepared to analyze posterior endothelial surface using a light microscope (24 corneas) and a scanning electron microscope (14 corneas). The equine posterior corneal endothelium surface observed by optical microscopy and scanning electron microscopy revealed a continuous layer of polygonal cells of uniform size and shape in both the control and treatment groups. Due to non-normal residuals at ANOVA mean comparison, a generalized linear model was utilized at 5% level of significance. The chi-square test stated that treatment and control group were not different statistically. The 0.05% brilliant blue did not cause damage to equine corneal endothelium.(AU)

Objetivou-se avaliar os efeitos imediatos de uma solução de 0,05% de azul brilhante sobre o endotélio da córnea de equinos. Trinta e oito córneas de 19 cavalos, machos ou fêmeas, de diferentes idades foram estudadas. As córneas foram divididas aleatoriamente em dois grupos. Grupo 1: O endotélio corneano foi perfundido com 0,3mL de azul brilhante 0,05% durante 60 segundos seguido por irrigação com uma solução salina balanceada. Grupo 2: O endotélio corneano foi perfundido com BSS durante 60 segundos. As córneas foram posteriormente excisadas com trépano de 8mm e preparadas para análise endotelial utilizando um microscópio óptico (24 córneas) e um microscópio eletrônico de varredura (14 córneas). A análise da superfície posterior do endotélio da córnea equina observada por microscopia óptica e microscopia eletrônica de varredura revelou uma camada contínua de células poligonais de tamanho e forma uniformes tanto no grupo controle quanto no grupo tratamento. Devido aos resíduos não normais na comparação da média de ANOVA, utilizou-se um modelo linear generalizado com nível de significância de 5%. Evidenciou-se com o teste qui-quadrado que não houve diferença estatística entre o grupo controle e o grupo tratamento. O azul brilhante de 0,05% não causou dano ao endotélio corneano de equinos.(AU)