Angiographic diagnosis of venous invasion with reference to liver metastasis of carcinoma of the colon

Angiography using Prostaglandin E1 was performed on thirty one cases with carcinoma of the colon in order to define the degree of venous invasion. Venous findings (occlusion and/or encasement) were classified into three groups: AG-V2, above mentioned venous findings up to marginal vein; AG-V1, these findings up to the vein of vasa recta; AG-V0, no distinct findings on the vein. 1) When angiographic findings were compared to histological findings of subserosal venous invasion, the results of AG-V2, AG-V1 and AG-V0 showed a positive correlation of 91.7%, 46.2% and 16.7%, respectively. 2) The angiographic findings were also correlated with the degree of fibrosis around carcinoma of the colon. 3) The incidence rate of liver metastasis in a group of AG-V2 was 50%. In AG-V1 it was 30.8% and in AG-V0 0%. 4) In the course of the postoperative follow-up, liver metastasis appeared in 2 cases of AG-V2 and AG-V1, respectively. The finding may suggest the existence of the liver metastases at the time of operation.     

High resolution localization of angiotensin II receptors in rat renal medulla.

The cellular localization of angiotensin II (Ang II) receptors in the inner stripe of the outer medulla of the rat kidney was investigated by using high resolution light and electron microscopic autoradiography. Fresh tissue blocks from the inner stripe of the outer medulla were incubated with 125I-[Sar1, Ile8] Ang II and prepared for microscopic autoradiography. At the light microscopic level, 125I-[Sar1, Ile8] Ang II was found to penetrate into the tissue and to bind specifically to sites outlining renal tubules and vasa recta bundles. Electron microscopic autoradiography revealed that silver grains were detected over interstitial cells located between the tubules and components of the vasa recta bundles, but no silver grains were detected overlying the cells of the thin descending or thick ascending limbs of the loop of Henle, the collecting ducts, the vasa recta, or other blood vessels. These interstitial cells contained abundant endoplasmic reticulum, microfilaments, occasional lipid droplets and extensive cytoplasmic processes which closely related to the basement membranes of the vasa recta and loops of Henle. The cells therefore closely resemble type 1 interstitial cells. Since Ang II binding sites are absent in the inner medulla, the cells labelled by this technique must be a subset of type 1 interstitial cells, distinct from the typical lipid-laden interstitial cells most abundant in the inner medulla. These findings demonstrate that type 1 interstitial cells are the primary sites for a high density of Ang II receptors located in the inner stripe of the outer medulla.     

Anti-B7-1 blocks mononuclear cell adherence in vasa recta after ischemia

BACKGROUND: Blocking the costimulatory pathway by CTLA-4 Ig, reactive with both B7-1 and B7-2 costimulatory molecules, protects the kidney during acute ischemia/reperfusion injury. This study investigated whether and how B7-1 and/or B7-2 proteins are involved in renal ischemia/reperfusion injury (IRI). METHODS: Uninephrectomized rats were submitted to warm renal ischemia (30 min) and received control monoclonal antibody (mAb; 17E3), anti-B7-1 (3H5), anti-B7-2 (24F), a combination of anti-B7-1/B7-2, or CTLA-4 Ig. Renal function, morphology, and the kinetics of inflammatory cells were studied for a ten-day period. Binding sites of the injected antibodies were detected by secondary staining with anti-mouse Ab. RESULTS: Compared with controls, acute renal failure (ARF) in the anti-B7-1 group was attenuated both functionally and morphologically. Anti-B7-1/B7-2 and CTLA-4 Ig also were protective in IRI. ARF was not altered by anti-B7-2 treatment. Two hours after reperfusion, B7-1 was expressed along the endothelial cells of the ascending vasa recta. Expression of B7-1 increased over time during the first 24 hours and decreased thereafter. Two hours after reperfusion, adherence/accumulation of T cells and monocytes/macrophages was found in the vasa recta of the ischemic kidney. Anti-B7-1-treated animals had fewer T cells and monocytes/macrophages in the vasa recta compared with controls. Leukocyte accumulation in these vessels after anti-B7-2 treatment was not different from IRI controls. CONCLUSION: These observations strongly support the key role of the B7-1 protein in the protection of renal IRI through inhibition of T cell and monocyte adherence at the level of the ascending vasa recta.     

P-selectin-dependent macrophage migration into the tubulointerstitium in unilateral ureteral obstruction

BACKGROUND: Interstitial infiltration of macrophages (M?) is one of the main causal factors for the tubulointerstitial injury. However, precise mechanisms of M? infiltration into tubulointerstitium have not been fully explored. The purposes of this study were to assess the role of selectins in the acute infiltration of M? in rats with unilateral ureteral obstruction (UUO) and to evaluate the role of vasa recta, that is, whether they facilitate massive influx of M? into the interstitium by functioning as specialized vessels. METHODS: To evaluate the role of selectins in M? infiltration into tubulointerstitium, the expression of selectins and L-selectin ligands was examined by immunohistochemistry and immunoelectron microscopy. The functional role of P-selectin in vasa recta was studied by Stamper-Woodruff assay, in vivo p-M? migration assay and in vivo blocking experiments with the monoclonal antibody (mAb) ARP2-4. RESULTS: Selective expression of P-selectin was detected in vasa recta as early as one hour after UUO, and the expression increased thereafter for 96 hours. In contrast, endothelial expression of L-selectin ligands and E-selectin were not detectable. In the Stamper-Woodruff assay on kidney sections of rats with UUO, the adhesion of isolated rat peritoneal M? (p-M?) to vasa recta was significantly inhibited by the mAb ARP2-4 (P-selectin blocker; P < 0.01), but not by mAb ARE-5 (E-selectin blocker) or rLECIg (rat L-selectin chimeric protein). In the in vivo transfer experiments with fluorescein-labeled p-M? into rats 48 hours after UUO, labeled p-M? had accumulated around vasa recta at three minutes and had infiltrated predominantly into the outer medulla at 180 minutes. The number of labeled p-M? was reduced when the rats were pretreated with ARP2-4 (P < 0.01). Finally, ARP2-4 (10 mg/kg), injected 15 minutes before UUO, reduced the number of infiltrated M? (P < 0.01). CONCLUSION: The results suggest that vasa recta, which express P-selectin, contribute to massive infiltration of M? into the interstitium by functioning as specialized post-capillary venules.     

采用多排螺旋CT评价肠系膜动脉栓塞致急性肠缺血的实验研究

目的评估多排螺旋CT（MDCT）检测动脉堵塞性急性肠缺血（ABI）的早期征象及其动态演化规律。方法12只巴马猪,随机分成4组,每组3只。经股动脉穿刺、插管行肠系膜上动脉（SMA）造影．用明胶海绵和血凝块栓塞其部分空肠和同肠分支。,于术前和术后3、6、9及12h用MDCT进行平扫和增强后动脉、静脉和延迟3期扫描,并用容积再现（VR）、最大强度投影（MIP）和薄层最大强度投影（TSMIP）技术进行肠系膜帆管重建。与DSA对比,观察CT血管造影（CTA）显示肠系膜血管正常解剖、SMA栓塞、肠系膜和肠道结构变化,比较栓塞后各时间点的动态变化。结果12只实验猪均显示ABI病理改变．随时间延长,缺血呈进行性加重。CTA显示全部57支栓塞粗管：34支未栓塞血管巾．CTA显示29支通畅．5支中断：CTA对栓塞血管的敏感性和特异性分别为100％和85．3％。TSMIP显示栓塞远端梳状分支血管和毛刷状密集直血管消失．以此标准,TSMIP正确定性24个栓塞肠段中23个和1全部12个正常肠段．敏感性和特异性分别为95．8％和100％。术后各时间点栓塞Ⅸ和非柃塞区肠壁强化值的差异均有统计学意义（P〈0．05）．．术后3h栓塞区三期的强化值均较术前明显降低,差异具有统计学意义（P〈0．001）：随栓塞时间延长肠壁强化呈减低趋势。栓塞3h后12只猪中有10只出现肠腔扩张、积液,且随时间延长程度加重。结论MDCT及CTA诊断动脉堵塞性ABI的早期直接征象为SMA血管中断．远端梳状或毛刷状密集直血管消失和肠段强化减弱：间接征象为肠腔扩张及积液：且这些征象具有一定的动态演化规律。     

Intestinal Intramural Vascular Anastomoses

Introduction: Present surgical techniques are rarely relying on intestinal intramural vascular anastomoses; however, this could open new limits in reconstructive surgery. Our aim was to study the efficacy of the antimesenteric and the longitudinal intramural vascular anastomoses in a porcine model. Material and Methods: Five minipigs were used. Antimesenteric anastomoses: jejunal loops were detubularized by cutting along the antimesenteric line (Control), in the middle between the mesenteric and antimesenteric border (Group 1) and close to the mesenteric line (Group 2). Mucosal microcirculation (red blood cell velocity, perfusion rate) was recorded with orthogonal polarization spectral imaging (Cytoscan A/R) at the long edge of the detubularized bowel. Longitudinal anastomoses: records were made on a continuous jejunal loop following antimesenteric incision, detubularization, and subsequent ligation of 2, 4, and 6 neighboring vasa recta in the middle of the loop. The same study was repeated on the free end of completely divided jejunal segments with ligation of 2, 4, or 6 vasa recta. Results: Antimesenteric anastomoses: There was no statistically significant difference in red blood cell velocity and perfusion rate between Control and Groups 1 and 2. Longitudinal anastomoses: The red blood cell velocity dropped significantly, while the perfusion rate did not change significantly after ligation of 4 vasa recta in the continuous loop. In the loop with a free end, however, both parameters decreased significantly after ligation of four vessels. Conclusion: It is safe to rely on antimesenteric intramural anastomoses but strong limitation of longitudinal intramural vascular anastomoses should be considered in intestinal reconstructions.     

The medullary microcirculation

Like other regional circulations, the medullary circulation supplies oxygen and other primary substrates to the medulla and removes carbon dioxide and other waste metabolites. It also acts as a countercurrent exchanger and simultaneously removes water reabsorbed from the renal tubule to preserve mass balance. Our present understanding of how the medulla serves both these functions at the same time is illustrated in Figure 3. Blood leaves the efferent arteriole with an elevated plasma protein concentration as a consequence of glomerular filtration, and flows down descending vasa recta within a vascular bundle. The increased interstitial osmotic-concentration coupled with a finite capillary reflection coefficient for small solutes causes additional water to be extracted so that at the termination of descending vasa recta, the plasma protein concentration exceeds that in the systemic circulation by approximately twofold. Solute, urea more than sodium chloride, also enters descending vasa recta. As blood flows through the interconnecting capillary plexus and up ascending vasa recta, transcapillary oncotic and osmotic pressure differences combine to cause capillary uptake of fluid. There is also simultaneous loss of urea such that the medullary trapping of urea is very effective. Countercurrent exchange of sodium chloride, however, appears to be less efficient and as a consequence, not only water but sodium chloride is removed from the medulla. Antidiuretic hormone reduces medullary blood flow, both directly by its vasoconstrictor (V1-receptor mediated) effect and indirectly by its antidiuretic (V2-receptor mediated) effects. Prostaglandins are able to enhance medullary blood flow by counteracting vasoconstrictive influences.(ABSTRACT TRUNCATED AT 250 WORDS)     

Urea and renal function in the 21st century: insights from knockout mice

Since the turn of the 21st century, gene knockout mice have been created for all major urea transporters that are expressed in the kidney: the collecting duct urea transporters UT-A1 and UT-A3, the descending thin limb isoform UT-A2, and the descending vasa recta isoform UT-B. This article discusses the new insights that the results from studies in these mice have produced in the understanding of the role of urea in the urinary concentrating mechanism and kidney function. Following is a summary of the major findings: (1) Urea accumulation in the inner medullary interstitium depends on rapid transport of urea from the inner medullary collecting duct (IMCD) lumen via UT-A1 and/or UT-A3; (2) as proposed by Robert Berliner and colleagues in the 1950s, the role of IMCD urea transporters in water conservation is to prevent a urea-induced osmotic diuresis; (3) the absence of IMCD urea transport does not prevent the concentration of NaCl in the inner medulla, contrary to what would be predicted from the passive countercurrent multiplier mechanism in the form proposed by Kokko and Rector and Stephenson; (4) deletion of UT-B (vasa recta isoform) has a much greater effect on urinary concentration than deletion of UT-A2 (descending limb isoform), suggesting that the recycling of urea between the vasa recta and the renal tubules quantitatively is less important than classic countercurrent exchange; and (5) urea reabsorption from the IMCD and the process of urea recycling are not important elements of the mechanism of protein-induced increases in GFR. In addition, the clinical relevance of these studies is discussed, and it is suggested that inhibitors that specifically target collecting duct urea transporters have the potential for clinical use as potassium-sparing diuretics that function by creation of urea-dependent osmotic diuresis.     

Urea transporters and renal function: lessons from knockout mice

PURPOSE OF REVIEW: Gene knockout mice have been created for the collecting duct urea transporters UT-A1 and UT-A3, the descending thin-limb urea transporter UT-A2 and the descending vasa recta isoform, UT-B. In this brief review, the new insights in our understanding of the role of urea in the urinary concentrating mechanism and kidney function resulting from studies in these mice are discussed. RECENT FINDINGS: The major findings in studies on urea transporter knockout mice are as follows: rapid transport of urea from the inner medulla collecting duct lumen via UT-A1 or UT-A3 is essential for urea accumulation in the inner medullary interstitium; inner medulla collecting duct urea transporters are essential in water conservation by preventing urea-induced osmotic diuresis; an absence of inner medulla collecting duct urea transport does not prevent the concentration of sodium chloride in the inner medulla interstitium; deletion of the vasa recta isoform UT-B has a much greater effect on urinary concentration than deleting the descending limb isoform UT-A2. SUMMARY: Multiple urea transport mechanisms within the kidney are essential for producing maximally concentrated urine.     

Papillary necrosis associated with calyceal arteritis.

The renal papilla has a double blood supply - from both the vasa recta and the calyceal arteries. The importance of the latter supply is not established. A case of polyarteritis associated with papillary necrosis is reported, in which the calyceal vessels, supplying the area, show acute necrotizing arteritis and occlusion. The pathophysiological and clinical implications are discussed.     

Clinical and genetic features of vascular Ehlers-Danlos syndrome

Vascular Ehlers Danlos syndrome (EDS) is a rare autosomal dominant inherited disorder of connective tissue resulting from mutation of the COL3A1 gene encoding type III collagen. Affected individuals are prone to serious vascular, intestinal, and obstetrical complications. Complications are rare during infancy but occur in up to 25% of affected persons before the age of 20 and 80% before the age of 40. Median survival is 48 years. Arterial rupture accounts for most deaths. Intestinal perforation, usually involving the colon, are less fatal. Pregnancy is a high risk for women with EDS. As for many rare orphan diseases, delayed and/or improper diagnosis can lead to inadequate or inappropriate treatment and management. Diagnosis is based on clinical findings including specific facial features, thin translucent skin, propensity to bleeding, and rupture of vessels and/or viscera. Diagnosis can be confirmed either by biochemical assays showing qualitative or quantitative abnormalities in type III collagen secretion or by molecular biology studies demonstrating mutation of the COL3A1 gene. Varied molecular mechanisms have been observed with different mutations in each family. No correlation has been established between genotype and phenotype. Diagnosis should be suspected in any young person presenting with arterial or visceral rupture, carotid dissection, or colonic perforation. There are currently no specific treatments for EDS.     

胸腰段最长肌表面滋养血管的解剖学特征及其术中保护

 目的 探讨胸腰段最长肌表面滋养血管的解剖学特征及在胸腰椎骨折后路经肌间隙入路手术中对其进行保护的作用。方法 采用骶棘肌肌间隙入路经后路椎弓根钉棒系统复位固定治疗胸腰椎骨折并获得完整随访的患者97例,于术中观察胸腰段最长肌表面滋养血管的走行和分布,应用特殊手术器械和技术对血管进行保护。评估术后第3天、1个月、6个月及拆除内固定术后1个月的疼痛视觉模拟评分（visual analogue scale,VAS）及术前、术后6个月的胸腰段最长肌MRI影像。结果 共观察97例194条最长肌402个椎弓根间区域的最长肌表面血管分布。402个区域中,94.3%的表面滋养血管呈束状,5.7%的区域中血管呈团状。在束状血管分布的379个区域中,血管束位于椎弓根区者占9.8%、椎弓根间上区76.0%、椎弓根间中区12.4%、椎弓根间下区1.8%;87.3%的血管束得以完整保留,12.7%的血管束以电凝烧灼处理。术中出血量为（21±9.3） ml。术后第3天、1个月、6个月及拆除内固定术后1个月VAS分别为（3.3±1.6）分、（2.1±1.4）分、（1.2±0.7）分、（1.1±0.7）分。术后6个月,经电凝烧灼处理的胸腰段最长肌在MRI上呈脂肪化改变。结论 胸腰段最长肌表面滋养血管一般呈束状,多位于椎弓根间上区。术中保护滋养血管能减轻对最长肌的损伤,减少术后肌肉脂肪化变性。     

Atrial natriuretic peptide and furosemide effects on hydraulic pressure in the renal papilla

Atrial peptides (ANP) have been shown to preferentially increase blood flow to juxtamedullary nephrons and to augment vasa recta blood flow. To determine the effect of this alteration in intrarenal blood flow distribution on pressure relationships in inner medullary structures and their significance as a determinant of ANP-induced natriuresis, we measured hydraulic pressures in vascular and tubule elements of the renal papilla exposed in Munich-Wistar rats in vivo during an euvolemic baseline period and again during an experimental period. Rats in Group 1 received intravenous infusion of rANP administered as a 4 micrograms/kg prime and 0.5 microgram/kg/min continuous infusion, and were maintained euvolemic by plasma replacement. Infusion of ANP resulted in significant natriuresis, diuresis and increase in inulin clearance. Within 90 seconds of initiation of this systemic infusion, vasa recta hydraulic pressures were markedly increased and exceeded the small pressure increment occurring in loops of Henle and collecting ducts. Infusion of furosemide in Group 2 rats at a dosage which reproduced the increase in urine flow in Group 1 was associated with small and equivalent increases in both vascular and tubule elements, indicating that the differential pressure response observed in Group 1 was not due to increased tubule fluid flow rates, but was rather a specific ANP-induced vascular effect. Group 3 rats received an infusion of ANP in a setting where its whole kidney hemodynamic effects were prevented. This resulted in a marked blunting of natriuresis and diuresis, and obliteration of the pressure differential between vasa recta and tubules observed in Group 1.(ABSTRACT TRUNCATED AT 250 WORDS)     

Role of aquaporin water channels in kidney function studied using transgenic mice

Several aquaporin (AQP) water transporting proteins are expressed in mammalian kidney: AQP1 in plasma membranes of proximal tubule, thin descending limb of Henle, and descending vasa recta; AQP2 in collecting duct luminal membrane; AQP3 and AQP4 in collecting duct basolateral membrane; AQP6 in intercalated cells; and AQP7 in the S3 segment of proximal tubule. To define the role of aquaporins in renal physiology, we have generated and characterized transgenic null mice deficient in AQP1, AQP3, and AQP4, individually and in combinations, as well as AQP2 mutant mice, in which the T126M mutation causing human nephrogenic diabetes insipidus was introduced. AQP1-deficient mice are polyuric and unable to concentrate their urine in response to water deprivation or vasopressin administration. AQP1 deletion greatly reduces osmotic water permeability in proximal tubule, thin descending limb of Henle, and descending vasa recta, resulting in defective proximal tubule fluid absorption and medullary countercurrent exchange. Mice lacking AQP3 have low basolateral membrane water permeability in cortical collecting duct and excrete large quantities of dilute urine. Mice lacking AQP4 have low water permeability in inner medullary collecting duct, but manifest only a mild defect in maximum urinary concentrating ability. These data, taken together with phenotype analyses of brain, lung, and gastrointestinal organs, support the paradigm that aquaporins facilitate rapid near-isosmolar transepithelial fluid absorption/secretion, as well as rapid vectorial water movement driven by osmotic gradients. The renal phenotype data in aquaporin knockout mice suggests the utility of aquaporin blockers as novel aquaretic-diuretic agents. Received: March 19, 2001 / Accepted: March 22, 2001     

The effect of aminoglutethimide on steroid synthesis of the adrenal gland and its use in prostate cancer

Following the hypothesis of depressing adrenal androgens in patients with relapsed prostatic carcinoma using Aminoglutethimide (AG), we performed a prospective study during three years, beginning in 1983. Twenty orchiectomized men aged 61-83 (mean 77) with progressive prostate carcinoma stage D2 (T0-4 Nx M1) were included. They received 4 x 250 mg AG and 50 mg cortisone daily. Overall response, according to NPCP-criteria, was 30% after 3 months (1 patient with partial remission and 5 patients stable), and at the end of trial 1 patient (5%) remained stable and 7 (65%) had progression. Laboratory controls of adrenal androgens did not show any significant change of androstenedione and DHEA-S within 3 months, and there was even an average rise of testosterone from 1 to 2 nmol/l. AG seems to be only of small advantage in secondary treatment of advanced prostatic carcinoma. But it is possible that aromatase inhibitors could be useful in treating BPH because of their influence on peripheral oestrogens.     

MSCTA肠系膜下动脉成像的临床应用

目的探讨多层螺旋CT血管造影（MSCTA）在肠系膜下动脉（IMA）成像中的临床应用价值。方法选择因直肠或左半结肠癌和血管性病变行MSCTA检查的患者75例，采用容积再现（VR）血管生长技术（AV）进行血管重建，观察肿瘤供血动脉及IMA狭窄或闭塞后的侧支循环情况。结果35例直肠癌患者中，显示肿瘤供血动脉：直肠上动脉35、直肠下动脉29例、骶正中动脉6例、乙状结肠动脉4例；7例乙状结肠癌由乙状结肠动脉供血；3例直肠乙状结肠交界区癌中，1例乙状结肠动脉供血，2例乙状结肠动脉和直肠上动脉供血；2例降结肠癌由左结肠动脉供血；5例脾曲癌由左结肠动脉升支和中结肠动脉左支供血。23例IMA狭窄或闭塞患者均有Riolan动脉弓侧支循环形成。结论MSCTA能清楚显示IMA参与肿瘤供血及准确评价其狭窄或闭塞后侧支循环形成情况。     

Aquaporins in endothelia

Aquaporin-1 (AQP1) water channels are expressed widely in microvascular endothelia outside of the central nervous system, including renal vasa recta and tumor microvessels, as well as in non-vascular endothelia in pleura, peritoneum, cornea, and lymphatics. In kidney, AQP1-facilitated water transport in outer medullary descending vasa recta is likely an important component of the urinary concentrating mechanism. However, in most vascular endothelia outside of kidney, it remains uncertain whether AQP1 expression and high water permeability are physiologically important. AQP1 in non-vascular endothelia at the inner corneal surface is involved in the maintenance of corneal transparency. Recently, a new role of AQP1 in endothelial cell migration was discovered in analyzing the cause of defective tumor angiogenesis in AQP1-deficient mice. AQP1 facilitates endothelial cell migration by a mechanism that may involve facilitated water transport across cell protrusions (lamellipodia). AQP1 inhibitors may thus have aquaretic and antiangiogenic activity.     

Pulmonary and systemic aneurysms in a case of widespread arteritis.

A patient in whom asthma preceded the development of multiple pulmonary and systemic artery aneurisms died after dissection of the aorta. At necropsy he was found to have widespread arteritis of unknown aetiology affecting many large and medium-sized pulmonary and systemic vessels as well as a few microscopic ones. Endarteritis obliterans was present in some of the vasa vasorum. The clinical and histopathological findings are discussed in relationship to other known causes of arteritis, and it is concluded that this condition has not previously been described.     

Divergent regulation of circulating and intrarenal renin-angiotensin systems in response to long-term blockade

BACKGROUND/AIMS: Long-term treatment with angiotensin-converting enzyme (ACE) inhibitors or angiotensin (Ang) II type I (AT(1)) receptor blockers can improve kidney function and attenuate the progressive decline in kidney function associated with age. In this study in Wistar rats medicated for 22 months, we determined the effects of enalapril (10 mg/kg/day) and losartan (30 mg/kg/day) treatment, in comparison with vehicle (tap water), on renal AngII receptor density and circulating and urinary components of the renin-angiotensin system (RAS). METHODS: Kidney sections were incubated with [(125)I-sarcosine(1)-threonine(8)]AngII (0.6 nM) for Ang receptor density, and Ang peptides were determined using radioimmunoassays. RESULTS: Receptor density was approximately 50% higher in vasa recta, glomeruli, and tubulointerstitium in enalapril-treated rats and lower in vasa recta and glomeruli in losartan-treated relative to vehicle-treated rats. Losartan and enalapril treatment elevated plasma levels of AngI and Ang-(1-7) while AngII increased only in losartan-treated rats. In contrast, both treatments were associated with a reduction in urinary excretion of all three Ang peptides as compared with control rats. CONCLUSION: The reduction in urinary Ang peptides with losartan and enalapril treatment suggests that blockade of intrarenal AngII may be an important mechanism underlying the renoprotection seen with such treatments.