No abstract available.
Rabbits*

No abstract available.
Rabbits*

No abstract available.
Rabbits*

No abstract available.
Rabbits*

No abstract available.
Rabbits*

PURPOSE: The aim of this study was to evaluate the effectiveness and indication of radiofrequency ablation(RFA) using renal VX2 tumors by implantation of VX2 tumor cells under the renal capsule in rabbits. MATERIALS AND METHODS: Ten rabbits were injected with 30-40microliter VX2 tumor cells(1.2x10(7) viable cells/ml) under the renal capsule of the right kidney by right subcostal incision. On the 14th day after the tumor cells were implanted, we checked for the development of renal tumors, and the sizes and shapes(exophytic or central) of the tumors by the use of computed tomography. We performed RFA in the renal VX2 tumors with a 17G StarBurst electrode through kidney exposure. After the first and third day following RFA, renal function was checked. On the third day, we performed CT and harvested the kidneys for gross and microscopic evaluation. RESULTS: We confirmed the development of renal VX2 tumors in nine cases. Tumor shapes were exophytic in seven cases and central in two cases; the mean size of the tumors was 2.1 cm(range, 1.1-3.8cm). In all tumors, RFA was performed. From the use of enhanced CT after RFA on the third day, all of the lesions treated with RFA showed no enhancement. From the pathological findings, coagulative necroses were seen on all of the lesions treated with RFA. The necrotized tumor size after RFA was not different statistically as measured by CT and a pathological examination (p=0.833) CONCLUSIONS:: In centrally located renal tumors, we experienced thermal injury in pelvocalyceal systems. RFA is an effective method for nephron sparing surgery as the tumor cells completely disappear and there is preserved renal function and the procedure is easy to apply. We suggest that the RFA method for exophytic renal tumors is more effective than other procedures.
Rabbits ; Animals

Experiments were carried out on adult rabbit without disease in anterior half-part of both eyes, weight 1.5 - 2 kg. Sulfuric acid 30% with dose 100 mcL can penetrate quickly to anterior chamber, reduce significantly the aqueous humor pH level within 90 minutes after burning and damage seriously to iris and anterior surface of lens. However, the aqueous humor pH level was normalized gradually by the body.
burns ; Rabbits

Roles of the nonclipped kidney in the development and maintenance of the high blood pressure in two- kidney, one clip hypertension remain to be defined. It has been known that the pathophysiology of hypertension is different by the presence or absence of the contralateral kidney in renal hypertension. The present study was undertaken to evaluate the effects of intrarenal norepinephrine in the nonclipped kidney exposed to the high blood pressure. Experiments were performed in 7-day two-kidney, one clip Goldblatt hypertensive and sham-operated normotensive rabbits. The basal levels of renal plasma flow and urine flow, and urinary excretion of electrolytes were higher in the nonclipped kidney of two-kidney, one clip Goldblatt hypertensive than in the corresponding kidney of sham-operated normotensive rabbits. Intrarenal infusion of norepinephrine increased renal perfusion resistance, and decreased renal hemodynamics and renal excretory function in a dose-dependent manner in both hypertensive and normotensive rabbits. The renal hemodynamics and excretory responses to intrarenal norepinephrine infusion were attenuated in two-kidney, one clip Goldblatt hypertensive rabbits. The changes by norepinephrine infusion of the renal excretory function were closely correlated with those in glomerular filtration rate or renal plasma flow. These results suggest that the impaired vascular reactivity in the nonclipped kidney is one of the early changes appeared in the course of multifactorial derangements in renal hypertension and that the impairment may be an adaptive response of the kidney to high blood pressure.
Rabbits ; Animals

Renin-angiotensin system is associated with development of diabetic nephropathy. Hyperglycemia is known as a primary etiologic factor about it. Thus, we investigated the effect of high glucose on angiotensin II(ANG II) binding in the primary cultured rabbit renal proximal tubule cells(PTCs). 25 mM glucose(48 hr incubation) induces inhibition of ANG II binding. The high glucose-induced inhibition of ANG II binding was recovered by the removal of glucose, suggesting the role of glucose specificity. High glucose-induced inhibition of ANG II binding was blocked by mepacrine and AACOCF3, phospholipase A2(PLA2) inhibitors. Indomethacin, a cyclooxygenase inhibitor, significantly prevented high glucose-induced inhibition of ANG II binding. However, nordihydroguaiareic acid(NDGA), a lipoxygenase inhibitor, and econazole, a cytochrome P450 epoxygenase inhibitor, did not block the effect of high glucose. This result suggest that cyclooxygenase metabolites of arachidonic acid(AA) released by high glucose are involved in the high glucose-induced inhibition of ANG II binding. Next, we examined the involvement of PKC in the effect of high glucose. Staurosporine, bisindolylmaleimide I, protein kinase C(PKC) inhibitors, and PD 98059, a p44/42 mitogen activated protein kinase(MAPK) inhibitor, significantly blocked high glucose- induced increase of [3H]-AA release and inhibition of ANG II binding. Indeed, 25 mM glucose increased PKC activity from cytosolic to particulate fraction and phosphorylation of p44/42 MAPK. In addition, high glucose increased phosphorylation of p44/42 MAPK and its activation was significantly blocked by PKC inhibitor. In conclusion, high glucose partially inhibits ANG II binding via PKC-MAPK-PLA2 signal pathway in the PTCs.
Rabbits ; Animals

The author carried out an experimentation to clarify a possible pathogenesis of renal papillary necrosis induced by an univisceral Shwartzman reaction. The experimental animals were healthy white rabbits in weighing between 1.7 kg and 3.0 kg. Under the condition of ureterostomy, animals were pretreated with 0.5 cc of 50% ethyl alcohol and followed by administration of 0.2 ~ 1.5 mg endotoxin (E. coli 026 : B6, bacto lipopolysaccharide B. Difco, U.S.A.) as preparation in the renal pelvis. And then sacrificed at 10 minutes, 30 minutes, 1 hour, 2 hours, 6 hours and 24 hours after intravenous injection of 0.2 mg or 0.6 mg endotoxin through the ear veins, subjection to examine light and electron microscopically. The obtained results were summarized as follows: Papillary necrosis was developed in 88% among 18 cases excluding 6 cases died before sacrification. There were two types of necrosis, namely papillary and medullary type, but the former and combined forms of both types were the most common findings. Initial main target site of injury in renal papilla induced by endotoxiin was the endothelium of vasa recta and then followed by the Henle's loop, interstitial cell and collecting tubule respectively. Vascular injuries such as swelling and detachment of endothelium were observed since 10 minutes after endotoxin injection. Henle's loop showed stratification of basement membrane without consistent features with time lapses and initially observed fatty vaculoes at 1 hour after endotoxin injection were more eminent in 24 hours group. Main changes of interstitial cells were decrease of lipid droplets while increase of fatty vacuoles; the latter were initially observed in 1 hour group and more eminent in 24 hours group. Collecting tubule showed many fatty vacuoles especially in 24 hours group. It is thought that emergence of fatty vacuoles seems to be a kind of immature lipid droplets to compensate the increased demand of PC release due to continuous ischemic condition. In conclusion, it is thought that ischemic injury due to the vascular changes is pathogenic mechanism producing renal papillary necrosis. Endotoxin induced univisceral Shwartzman reaction in the kidney may be a good experimental model in studying renal papillary necrosis.
Rabbits ; Animals