Microinjection study of p-aminohippurate excretion by rat kidneys

Baines, A. D.; Cw, Gottschalk; Lassiter, WE

doi:10.1152/ajplegacy.1968.214.4.703

Cited by 30 publications

(11 citation statements)

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“…The presumed carrier appears to be located at the luminal membrane since direct recovery was increased with urate loading. Systemic loading of rats with PAH, which is known to undergo bidirectional transport in the proximal tubule (6,16,17), demonstrated competition between urate and PAH in the proximal tubule. Urate recovery following proximal microinjection in PAHloaded rats was increased, but recovery after distal injection was unchanged.…”

Section: Discussionmentioning

confidence: 99%

“…In some rats probenecid (100 mg/kg body weight) or pyrazinoic acid (10,50, or 100 mg/kg body weight) was slowly infused (5-8 min) into the femoral vein 30-40 min before the abdominal surgery. In another group of rats a 1% solution of sodium p-aminohippurate (PAH) in saline was continuously infused during the experiment, after an appropriate priming dose (6).…”

Section: Methodsmentioning

confidence: 99%

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Urate-2-14C transport in the rat nephron

Kramp¹,

Lassiter²,

Gottschalk³

1971

J. Clin. Invest.

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A B S T R A C T Intrarenal transport of urate-2-1'C was studied in anesthetized rats using the microinjection technic. During saline diuresis, small volumes of urate-2-14C (0.24-0.48 mM) and inulin-8H were injected into surface proximal and distal convoluted tubules, and ureteral urine was collected serially. Total (74-96%) and direct (57,84%) urate recovery increased significantly the more distal the puncture site. Delayed recovery (+20%) remained approximately the same regardless of localization of the microinjection. After proximal injections, total and direct recoveries of urate-2-14C were significantly higher in rats treated with probenecid, pyrazinoate, or PAH than during saline diuresis alone, while the excretion rates were comparable after distal injection. Delayed recovery was not altered by drug administration. The decreased proximal reabsorption of urate is presumably due to an effect of the drugs on the luminal membrane of the nephron. For perfusion at high urate concentrations, nonradioactive urate was added to the injectate (0.89-1.78 mM). Urate-2-14C recovery was almost complete and there was no delayed excretion, demonstrating saturation kinetics. These findings are compatible with a carriermediated mechanism for urate transport probably located at the luminal border of the proximal tubular epithelium. No definitive evidence for urate secretion was found in these studies. INTRODUCTIONAlthough the renal excretion of urate has been extensively studied, the site(s) and mechanism(s) for urate

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Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Urate-2-14C transport in the rat nephron

Kramp¹,

Lassiter²,

Gottschalk³

1971

J. Clin. Invest.

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“…This discrepancy becomes important in relation to the question of passive back diffusion of PAH. Significant pass ive back diffusion of PAH, under conditions of maximal tubular secretion, has been demonstrated by micropuncture techniques in the rat [7] and the dog [8], In clearance studies, passive back diffusion is recognized by pro gressive reduction of net tubular secretion (TS), as plasma concentration increases -a form of self-depression of Tm [9], Regression A approaches ex cretion rate as p-hippurate increases causing TS to decrease and is thus con sistent with passive back diffusion. This is not the case for regression B.…”

Section: Discussionmentioning

confidence: 95%

Factors Affecting the Ultrafilterable Fraction of <i>o</i>-Iodohippurate in Human Plasma

Bryan¹,

Richardson²,

Lee³

et al. 1974

Nephron

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The ultrafilterable fraction (UF/P) of ¹³¹labeled o-iodohippurate (OIH) was measured in vitro and the effects of varying plasma OIH concentration (pOIH), plasma protein concentration (pPr) and plasma pH (ppH) determined. Dialysis coils were perfused with saline and human plasma at 38°C and pOIH varied (n = 46; pPr = 6.3–7.1 g/100 ml; ppH = 7.2–7.6), pPr varied (n = 126; pOIH = 50 mg/l00 ml; ppH = 7.2–7.6), or ppH varied (n = 121; pOIH = 84–106 mg/l00 ml). Ultrafiltrate was collected at different pOIH (10–90 mg/l00 ml), pPr (0–26 g/l00 ml), and ppH (5.7–9.8) values.Saline pPr constant pOIH constant

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“…Although bidirectional movement of PAH may be demonstrated in the proximal convoluted tubule, free-flow micropuncture studies have indicated that net secretion of this organic acid occurs between the late portion of the proximal convoluted tubule and the distal tubule (2,(4)(5)(6)(7). Isolated nephron studies in the rabbit kidney have shown that the pars recta is the major site of niet secretion of PAH (1).…”

Section: Introductionmentioning

confidence: 99%

Renal Tubular Transport of Organic Acids

Weinman¹,

Frankfurt²,

İnce³

et al. 1978

J. Clin. Invest.

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A B S T R A C Ttubule anid late proximal tubule yielded urinary recoverv rates of 85+3% and 101+2%, respectively, suggesting that oxalate absorption does occur in the mlid-portionis of the proximal tubule. Droplet precessioni studies confirmed a secretorv flux for oxalate. In contrast to oxalate, para-aminlohippurate (PAH), the more traditional marker for organic acid transport, was secreted in the late portions of the proximal tubule and in large measure at a site between the late proximal and distal tubules, presumably the pars recta. Probenecid inhibited PAH secretion but was w%ithout effect on net oxalate transport, oxalate absorption, or oxalate secretion.These studies demiionistrate that net oxalate secretion ocecurs in the earlx portions of the proximlal convoltuted tubule, uinidergoes bidirectional trainsport of approxim-atel e(qulal milagnittude in later segmiienits of the proximual tubtule, aind problalyl is not transported in imiore distal nephroni sites. The secretory mechaniism for oxalate differs fromn that of PAH in that it is located in a differenit segment of the nephroni and is not inhibited by probenecid. These differences These studies wvere performiied wvhile Dr.

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Microinjection study of p-aminohippurate excretion by rat kidneys

Cited by 30 publications

References 0 publications

Urate-2-14C transport in the rat nephron

Urate-2-14C transport in the rat nephron

Factors Affecting the Ultrafilterable Fraction of <i>o</i>-Iodohippurate in Human Plasma

Renal Tubular Transport of Organic Acids

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