The effect of exogenous angiotensin on superficial and deep glomeruli in the rat kidney

Hornych, Helena; Beaufils, M.; Richet, G

doi:10.1038/ki.1972.117

Cited by 95 publications

(33 citation statements)

References 15 publications

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“…The specific role of AII in volume homeostasis has been related to the capacity to regulate aldosterone release (7,26) and has been proposed to regulate the rate of glomerular filtration through its intrarenal release via tubulo-glomerular feedback (27)(28)(29)(30)(31)(32)(33)(34). Specific quantitative observations on the effects of AII on the glomerular permeability coefficient have not been previously described, although previous studies have speculated that AII might reduce glomerular capillary radius (9,10). This effect might be mediated by activation of contractile properties of the mesangial cell (35).…”

Section: Resultsmentioning

confidence: 84%

“…Therefore, the biologic activity of AIl, has been well defined for both vascular smooth muscle and the adrenal cortex in prior studies. Hornych et al have recently demonstrated that both pressor and subpressor quantities of Asn-1, Val-5 AII produced significant constriction of glomerular capillaries of the rat, as evaluated by scanning microscopy (9). Also, investigations by Sraer et al, utilizing isolated glomeruli, have shown a reduction in glomerular diameter when glomeruli were suspended in solutions containing Asn-1, Val-5 AII (10).…”

Section: Introductionmentioning

confidence: 95%

See 1 more Smart Citation

Angiotensin II effects upon the glomerular microcirculation and ultrafiltration coefficient of the rat.

Blantz¹,

Konnen²,

Tucker³

1976

J. Clin. Invest.

398

159

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A B S T R A CT The effects of both synthetic and biologically produced angiotensin II (AII) upon the process of glomerular filtration were examined in the plasma-expanded (2.5% body wt) Munich-Wistar rat, by micropuncture evaluation of pressures, nephron plasma flow (rpf) and filtration rate (sngfr). Plasma expansion was chosen as a control condition because (a) response to AII was uniform and predictable, (b) endogenous generation of AII was presumably suppressed, and (c) the high control values for rpf permitted accurate determination of values for the glomerular permeability coefficient (LPA) before and during AII infusion. With subpressor quantities of synthetic Asn-1, Val-5 AII (< 5 ng/100 g body wt/min), sngfr fell from 47.7 in the control group to 39.8 nl/min/g kidney (P < 0.005). The rpf fell to 60% of control values (P < 0.001). Measurement of glomerular capillary (Pa) and Bowman's space (P.) hydrostatic pressures in surface glomeruli with a servo-nulling device permitted evaluation of the hydrostatic pressure gradient (AP = Pa-P0). AP increased from 38.1+±1.2 in control to 45.9±1.3 mm Hg after Asn-1, Val-5 AII and essentially neutralized the effect of decreased rpf in sngfr. The sngfr then fell as a result of a decrease in LPA from 0.063+0.008 in control to 0.028±0.004 nl/s/g kidney/mm Hg after Asn-1, Val-5 AII (P < 0.02).Lower doses of Asp-1, Ile-5 AII (< 3 ng/100 g body wt/min) had no effect on sngfr, rpf, AP, and afferent and efferent vascular resistance, but significantly elevated systemic blood pressure, suggesting peripheral ef- fects on smooth muscle at this low dose. LPA was 0.044+ 0.007 nl/s/g kidney/mm Hg after low-dose Asp-1, Ile-5 AII, and 0.063±0.008 in the control group (0.2 > P > 0.1). Higher, equally pressor doses of native AII (5 ng/ 100 g body wt/min) produced effects almost identical to similar quantites of synthetic Asn-1, Val-5 AII upon rpf, AP, sngfr, and renal vascular resistance. LPA again fell to 0.026±0.004 nl/s/g kidney/mm Hg, a value almost identical to that after the synthetic AI. Paired studies with Asp-1, Ile-5 AII also demonstrated a consistent reduction in LPA.Both synthetic (Asn-1, Val-5 AII) and native AII (Asp-1, Ile-5 AII) produce a reduction in LpA, presumably by direct action on the glomerular capillary or mesangium, where no smooth muscle cells are present. Although quantitative differences in peripheral vascular effects of the two forms of AII are demonstrated, the effects on LPA occur at similar doses of both agents in the plasma-expanded rat. A third major physiologic action for AII is postulated that requires an effector cell in the glomerulus that differs from those previously demonstrated for vascular smooth muscle and the adrenal glomerulosa.

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Section: Resultsmentioning

confidence: 84%

Section: Introductionmentioning

confidence: 95%

Angiotensin II effects upon the glomerular microcirculation and ultrafiltration coefficient of the rat.

Blantz¹,

Konnen²,

Tucker³

1976

J. Clin. Invest.

398

159

View full text Add to dashboard Cite

show abstract

“…It can also be considered that a low proximal tubular reabsorption will result in an increased delivery of filtrate to the macula densa, which, by a feedback mechanism, will result in a decrease in glomerular filtration rate (38)(39)(40). It is of interest to note in this regard, that plasma levels of renin were found to be markedly elevated in newborns (41,42) and that angiotensin was found recently to induce selectively vasoconstruction of the glomerular capillaries of the superficial nephrons (43). Furthermore, indirect and direct methods have documented a high intrarenal vascular resistance in the immediate newborn period and a steep fall thereafter (5,6,23,44).…”

Section: Methodsmentioning

confidence: 99%

Functional and Morphologic Maturation of the Superficial Nephrons RELATIONSHIP TO TOTAL KIDNEY FUNCTION

Spitzer¹,

Brandis²

1974

J. Clin. Invest.

141

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A B S T R A C T The functional and morphologic pattern of superficial nephron development was studied in guinea pigs ranging in age between 2 h and 38 days. Concomitent measurements of total kidney function and glomerular counts were also performed.Superficial nephron glomerular filtration rate was found to increase from 0.92 to 19.32 nl/min. The filtration rate of the entire kidney rose from 0.19 to 1.31 ml/ min. During the first 15 days of life the average rate of increase in glomerular filtration rate per nephron (0.48 nl/min-day), obtained by dividing the increase in total kidney glomerular filtration rate by glomerular number, was more than twice the observed rate of increase in the superficial nephrons (0.21 nl/min-day). During the remainder of the first month, the increase in superficial nephron glomerular filtration rate (0.97 nl/min-day) was greater than the average increase for all nephrons (0.71 nl/min-day). Thus, the initial increase in total kidney glomerular filtration rate was primarily a consequence of the activity of the deep nephrons, whereas during the ensuing period the superficial nephrons appeared to be the sole contributors to the change in total kidney glomerular filtration rate.The increase in superficial nephron glomerular filtration rate was found to correlate closely with the increase in proximal tubular length. Functional glomerulotubular balance was maintained throughout the entire period of renal maturation.

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“…In this respect, it is of interest that glomerular volume did not increase with enalapril in the control group (3SE). Previous studies in the rat have shown that angiotensin-induced changes in glomerular volume vary with nephron population and with the dose of angiotensin infused (15,16). Since angiotensinmediated vasoconstriction is enhanced in the obstructed compared to the intact kidney (4), it is not surprising that glomerular volume also differs.…”

Section: Is[iicts Of Cpuo On Normal Renal Growth Since Kidney Weightmentioning

confidence: 99%

Morphologic Correlates of Renal Growth Arrest in Neonatal Partial Ureteral Obstruction

et al. 1987

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ABSTRACT. To investigate the morphologic correlates of decreased renal blood flow and growth arrest resulting from chronic partial ureteral obstruction in the neonate, guinea pigs were subjected to unilateral ureteral constriction within the first 2 days of life and were studied at 3 and 8 wk of age. Severity of histologic changes in the obstructed and intact contralateral kidney was assessed by light microscopy. Morphometric glomerular measurements were made using a computerized tracing device. Since contralateral nephrectomy or administration of angiotensin converting enzyme inhibitor (enalapril) result in increased blood flow to the obstructed kidney, morphologic changes were also examined in separate groups of animals subjected to these maneuvers, and were compared to appropriate controls. Ipsilateral chronic partial ureteral obstruction resulted in decreased glomerular volume ( p < 0.0001) and increased glomerular crowding associated with tubular dilatation and progressive glomerular sclerosis, tubular atrophy, and interstitial fibrosis. The intact contralateral kidney underwent hypertrophy with increase in glomerular volume ( p < 0.0001) and decreased glomerular density.Contralateral nephrectomy prevented the decrease in glomerular volume in the obstructed kidney and resulted in decreased glomerular density and reduced tubular atrophy at 3 wk of age. Enalapril prevented the decrease in glomerular volume at 3 wk of age, but glomerular and tubular changes progressed and were unaffected by enalapril at 8 wk. Left kidney glomerular volume was directly related to renal blood flow ( r = 0.71, p < 0.05). We conclude that renal growth arrest due to chronic partial ureteral obstruction in the neonatal guinea pig is related at least in part to renal ischemia which contributes to progressive parenchymal damage. Ischemia is mediated initially by angiotensin I1 and by endogenous renal growth factor(s) controlled by functional renal mass. (Pediatr Res 21: 338-346, 1987) Abbreviations CPUO, chronic partial ureteral obstruction RBF, renal blood flow PAS, periodic acid-Schiff Obstructive nephropathy remains an important cause of renal insufficiency in infancy and childhood (I).

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The effect of exogenous angiotensin on superficial and deep glomeruli in the rat kidney

Cited by 95 publications

References 15 publications

Angiotensin II effects upon the glomerular microcirculation and ultrafiltration coefficient of the rat.

Angiotensin II effects upon the glomerular microcirculation and ultrafiltration coefficient of the rat.

Functional and Morphologic Maturation of the Superficial Nephrons RELATIONSHIP TO TOTAL KIDNEY FUNCTION

Morphologic Correlates of Renal Growth Arrest in Neonatal Partial Ureteral Obstruction

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