H�modynamik des Nierenmarks

Thurau, Klaus; Deetjen, P.; Kramer, Kürt

doi:10.1007/bf00583424

Cited by 189 publications

(28 citation statements)

References 9 publications

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“…6 demonstrates that PPF was consistently higher in animals undergoing a water diuresis than in hydropenic rats. This finding is in agreement with previous studies by Thurau et al (13) and Fourman and Kennedy (14). Whether this increase in flow was related to suppression of antidiuretic hormone release or action, volume expansion, local changes in the rheology of the medullary circulation, or other factors was not evaluated in this study.…”

Section: Introductionsupporting

confidence: 91%

Studies on the Mechanism of Reduced Urinary Osmolality after Exposure of the Renal Papilla

Chuang¹,

Reineck²,

Osgood³

et al. 1978

J. Clin. Invest.

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A B S T R A C T Studies were performiied in MlunichWistar rats to determine whether chaniges in papillary plasma flow might be responsible for the conicentrating defect which occurs after exposure of the extrarenal papilla. Papillary plasma flow was measured by 1251_ albumin accutnmulation. Initial studies in hydropenic animals revealed that papillary plasma flow was 40% higher in the kidney with the exposured papilla, 41 vs. 29 ml/min per 100 g of papilla (P < 0.001). This increase in papillary plasma flow was detectable 15 or 45 min after renmoving the ureter. Because it was unclear whether the rise in papillary plasnma flow was a cause or the result of the fall in urine osmolality, similar studies were performed in animals undergoing a water diuresis. In this setting, papillary plasma flow still increased on the exposed side compared to the control side, 81 vs. 60 ml/min per 100 g, despite similarly low uirine osmolalities of 155 and 174 mosmol/kg, respectively. This finding is compatible with the possibility that papillary exposure per se causes an increase in papillary plasma flow and that this hemodynamic alteration may lead to a reduction in urinary osmolality secondary to washout of the medullary interstitium. A final group of hydropenic rats was given either indomethacin or meclofenamate before removing the ureter. In these studies, there was no difference in either the papillary plasma flow or the urine osmolality between control and exposed kidneys. It is therefore suggested that opening the ureter induces an increase in papillary plasma flow by some mechanism which may involve an alteration in prostaglandiin synthesis.

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Section: Introductionsupporting

confidence: 91%

Studies on the Mechanism of Reduced Urinary Osmolality after Exposure of the Renal Papilla

Chuang¹,

Reineck²,

Osgood³

et al. 1978

J. Clin. Invest.

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“…There is evidence that the blood flow through the renal papilla is reduced during the elaboration of a concentrated urine, and it is possible that vasopressin is responsible for this reduction (Thurau, Deetjen and Kramer, 1960;Fourman, 1964). Thus, the variability in response to vasopressin in these experiments could be due to minor variations in the timing of the response to the injection.…”

Section: Resultsmentioning

confidence: 99%

The Effect of Vasopressin Upon the Distribution of Serum Albumin in the Rat Kidney

Cross

Sherrington

Thornton

1966

Aust J Exp Biol Med

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Summary. The effect of sniall doses of vasopressin (100 jiU) upon the distribution of Ii'''! labelled serum albumin in the rat kidney was studied.In all animals the papilla took up more senuii albumin than did the medulla or the cortex.The uptake of albumin into the papilla of rats given vasopressin was significantly more variable than the uptake into the papilla of control rats. In some experimental animals the uptake of isotope was less than that of the controls, while in others the uptake was greater than in the control animals.

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“…There may, however, be a species difference, since in the four experiments in hamsters a larger change was found, and also in dogs by Levitin et al [1962] and Perlmutt [1962]. It is uncertain whether this is due to increased circulation in the medulla [Thurau et al, 1960] or to an alteration in an active sodium transport.…”

Section: Sodium and Ureamentioning

confidence: 94%

Composition of the Renal Cortex and Medulla of Rats During Water Diuresis and Antidiuresis

Saikia

1965

Exp Physiol

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The composition of the renal papilla, medulla and cortex was studied in rats during hydropenia and water diuresis, and a few observations were made on hamsters.In confirmation of earlier findings, osmolality increased progressively from the outer medulla towards the tip of the papilla in hydropenia; this osmolal gradient was due largely to increasing concentration and content of sodium and urea. The osmolality at the tip was close to that of simultaneously collected urine. In water diuresis, this osmolal gradient was smaller but still present.Ammonium content and concentration increased progressively from the outer medulla towards the papilla.In water diuresis, the concentration and content of urea fell, but the gradient was still present. Sodium was little altered, and the fall in ammonium content, though considerable, contributed little to the total osmolal change.Potassium concentration and content were high in the terminal segment in diuresis and antidiuresis, and in water diuresis exceeded the hydropenic value.The water content increased progressively from the outer towards the inner medulla, but at the tip it was lower than in the adjacent segment. This distribution was qualitatively similar in both conditions, but the absolute level was higher in all medullary segments in water diuresis.The results are discussed in relation to the mechanism of production and maintenance of medullary hypertonicity. O'Dell, 1959, sheep, 1961, beaver, rabbits and psammomys; Eigler et al., 1962, rats; Levitin et al., 1962, dogs] have revealed that the sodium and urea concentration rises progressively from the cortico-medullary junction towards the medulla and papilla. It is clear from chemical, cryoscopic [Wirz et al., 1951; a] and direct micropuncture [Wirz, 1953[Wirz, , 1957Gottschalk and Mylle, 1959;Gottschalk, 1961;Lassiter et al., 1961] studies that in hydropenia the osmolality of medullary interstitial fluid rises progressively from the cortico-medullary junction towards the medulla and papilla.Observations during water diuresis are fewer. The medulla is still hypertonic to plasma in dogs [Ullrich et al., 1955;Ullrich and Jarausch, 1956;Levitin et al., 1962], and in rats , but the mechanism involved in establishing the differences between hydropenia and water diuresis is poorly understood.In an attempt to elucidate the mechanism involved, the chemical composition of cortex, medulla and papilla of rats and hamsters was analyzed during hydropenia and water diuresis. In particular, the relative contributions of sodium and urea, and the variation in water content, were studied.

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H�modynamik des Nierenmarks

Cited by 189 publications

References 9 publications

Studies on the Mechanism of Reduced Urinary Osmolality after Exposure of the Renal Papilla

Studies on the Mechanism of Reduced Urinary Osmolality after Exposure of the Renal Papilla

The Effect of Vasopressin Upon the Distribution of Serum Albumin in the Rat Kidney

Composition of the Renal Cortex and Medulla of Rats During Water Diuresis and Antidiuresis

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