摘要:

Following an overnight fast and oral hydration, some normal individuals developed a marked natriuresis. This renal salt wasting could be promptly curtailed by the ingestion, or in some cases, infusion of glucose. Infusion of insulin alone also was capable of decreasing urinary sodium excretion. Older subjects appeared more prone to develop an exaggerated natriuresis following fasting and hydration and developed more striking salt retention following carbohydrate ingestion than did younger subjects. Young subjects, restudied after longer periods of fasting (36 hours), still failed to develop a natriuresis following hydration. The hypothesis that the hyponatremia in acutely and chronically ill patients might develop, at least in part, as a result of excess salt loss during periods of inadequate carbohydrate intake was tested. Acutely and chronically ill patients, many with mild hyponatremia, failed to develop inappropriate salt loss with overnight fast and hydration. These findings failed to support this hypothesis.

ISSN:1660-8151    

DOI:10.1159/000179830

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

This study was conducted on anesthetized dogs utilizing an electromagnetic flowmeter probe around the renal artery and inulin extraction ratios for the calculation of glomerular filtration rate. At maximal ureteral pressures, renal blood flow increased to almost twice the control values. Glomerular filtration rate increased slightly, but significantly, with small elevations in ureteral pressure and returned, with further elevations, to values not significantly different from control. Renal arterial pressure-blood flow relationships demonstrated that autoregulatory capacity was diminished with ureteral pressure elevation, and a nearly passive behavior was observed at maximal ureteral pressures. Urine flow progressively decreased as the ureteral pressure was elevated and approximately half of the dogs could not generate ureteral pressures above 60 mm Hg. Sodium and chloride excretion rates decreased to a greater, potassium to a lesser, and osmolal excretion rates to the same extent as urine flow. Upon return to zero ureteral pressure, polyuria was observed although the sodium, chloride, and osmolal excretion rates were not significantly different from control values. RBF and GFR also returned to control levels and autoregulatory capacity was re-established. The results are interpreted to indicate that elevation of ureteral pressure results in a reversible decrease in vascular resistance at preglomerular sites through some feedback mechanism which may involve factors within the tubular network.

ISSN:1660-8151    

DOI:10.1159/000179831

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

Plasma renin activity was measured before and after dialysis in 27 uremic patients on a chronic dialysis program. Pre-dialysis renin levels were variable; the highest value occurred in the only patient with malignant hypertension. With this exception, there was no correlation between blood pressure and renin. Renin substrate levels were normal. After dialysis, renin activity rose significantly. There is a suggestive correlation between the decrease in mean arterial pressure and the increase in renin activity during dialysis. Biopsy and autopsy specimens of four kidneys examined with the Bowie stain demonstrate some normal JG cells with granules in the severely scarred kidneys. These cells may synthesize renin at an enormous rate to maintain normal plasma levels. In addition, uremic plasma appears to be deficient of a normal inhibitor or possibly contains an accelerator of the reaction between renin and its substrate.

ISSN:1660-8151    

DOI:10.1159/000179832

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

Blood loss in the Kolff twin-coil artificial kidney has been studied by radio-isotopic techniques using 51Cr and 59Fe and the results so obtained compared with the Hb and microhaematocrit methods. It has been shown that the true blood losses are considerably higher and more variable than those obtained by simple methods. The losses can be minimised by using Ultra-flo 100 coils (Baxter-Travenol) rather than Chron-a-coils (Baxter-Travenol), by altering the position of the coil during the wash-back procedure and by varying the composition and pressure of the wash-back fluid. The losses may be sufficient to account for the development of iron deficiency in patients on maintenance dialysis therapy.

ISSN:1660-8151    

DOI:10.1159/000179833

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

Previous detailed studies of the transport of hypoxanthine and uric acid indicate that these two oxypurines are handled by rather different processes. This report gives information on another important oxypurine, xanthine. Rabbit renal cortex slices were found to accumulate 14C-xanthine to concentrations significantly above those in the bathing solution (slice: medium or S/M ratios of about 2.0). This uptake is energy dependent as indicated by the effects of metabolic inhibitors. Carrier mediation was also probably involved and a relatively sharp pH optimum was noted. A requirement for potassium was also observed, but it was not nearly as marked as that seen for uric acid. Various agents (proben-ecid, octanoate, decanoate, etc.) known to inhibit organic acid transport were tested and found to reduce xanthine uptake significantly. The non-metabolizable amino acid, α-aminoisobutyric acid, did not block accumulation, however. Several organic bases were also without effect. A most significant finding was that several purine substances (including adenine and guanine) did not block accumulation. In general these data indicate that xanthine is transported mainly by the organic acid transport system (i.e. p-aminohippurate system) and not by the processes that handle hypoxanthine

ISSN:1660-8151    

DOI:10.1159/000179834

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

Le comportement de l’Inuline-3H, de l’Urée-14C, du Sodium, du Potassium et de la pression osmotique le long des tubules corticaux accessibles a été étudié par microponction chez trois lignées de souris (RAP, CBA, Pérou) en diurèse saline. Dans l’ensemble, les résultats obtenus chez cette espèce ne sont pas qualitativement différents de ceux rapportés antérieurement pour d’autres espèces de rongeurs places dans des conditions expérimentales voisines. Les differences les plus notables observées résultent de la petite taille des reins et de la réduction de la longueur des néphrons; ainsi, les tubules proximaux superficiels (pars recta comprise) sont courts (Pérou: 3,8 mm, CBA: 6,2 mm, RAP: 6,5 mm); corrélativement, les taux de filtration mesurés par néphron sont bas (respectivement 5,8, 8,5 et 12,4 nl/min) et la reabsorption fractionnaire de l’eau est limitée le long du tubule proximal: (F/PIn) = 2 à la fin de la portion accessible. En outre, dans les conditions de ces expériences, on observe chez les 3 lignées de souris une excrétion tubulaire de potassium dans la portion terminale des néphrons ainsi qu’un «recyclage» médullaire d’urée entre canaux collecteurs et anses de Henle attesté par une addition nette d’urée entre le tubule proximal et le tubule distal (F&slash;P)urée&slash;inuiine = 0,7 environ à la fin du proximal et 1,9 (R

ISSN:1660-8151    

DOI:10.1159/000179835

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

(1) Various heterologous tissues incorporated in Freund’s complete adjuvant were given to rats by i.p. injection every two weeks. Kidney emulsions produced a nephrotic syndrome, and a membranous glomerulo-nephropathy. Immunization with kidneys from rabbits, guinea pigs and man produced approximately the same incidence of disease. (2) The renal disease produced by heterologous kidneys appeared immunopathogenetically identical to the lesion elicited by homologous or autologous kidneys. (3) Liver, lung, muscle, intestine and placenta were less effective in producing renal disease than was renal tissues; the disease incidences could not be shown to be significantly different from controls receiving Freund’s adjuvant alone, with the number of animals studied. (4) Kidneys obtained from nephrotic children who had died from intercurrent infections and from patients who had died of lupus with nephritis were just as antigenic in inducing this disease as were healthy human kidneys. Kidneys obtained from children who died in uremia with ‘idiopathic’ chronic nephritis yielded a significantly decreased disease incidence. (5) Kidneys obtained from rats with aminonucleoside nephrosis, experimental autoimmune nephrosis or nephrosis due to heteronephrotoxic sera all yielded decreased incidences of renal disease. This was noted regardless of the duration of the donors’ experimenta

ISSN:1660-8151    

DOI:10.1159/000179836

出版商:S. Karger AG    

年代:1970

数据来源: Karger

ISSN:1660-8151    

DOI:10.1159/000177490

出版商:S. Karger AG    

年代:1970

数据来源: Karger

ISSN:1660-8151    

DOI:10.1159/000177485

出版商:S. Karger AG    

年代:1970

数据来源: Karger