Renal tubular function

Natiuretic response to diuretics including fruse-mide and bumetanide is reduced as a result of decreased renal tubular secretion of diuretic Thus, age-related changes in renal tubular function may influence not only pharmacokinetics but also drug action on the kidney (pharmacodynamics). 

It is only when the renal tubular function becomes disturbed that hyperamino aciduria appears, in comparison to normal subjects, under the influence of protein overloading in the diet (S34). Dubois et al. attribute also to the same renal tubular deficiency the temporary rise in amino aciduria observed in the first days of high-protein dietary treatment of kwashiorkor cases (D25, D26), a situation which has also been seen by others (C9, M4). It has been attributed both to hepatic and renal deficiencies (C3). 

According to Jonxis and Huisman (J6, J9, J12), hyperamino aciduria may be observed among the other members of the family of a patient with common rachitis and may sometimes (but not always) be corrected by vitamin D administration. There are presumably different grades of hereditary vitamin sensitiveness of the renal tubular function to vitamin D. The regulation does not take place through the mediation of the parathyroid hormone. 

A 6-year-old girl with Hirschsprung s disease had jeju-nostomy at 1 month followed by parenteral nutrition (47). Her calcium intake was 1-1.5 mmol/kg/day. Her urinary calcium rose from 3 months of age her serum calcium concentrations remained within the reference range but started to rise when she was 3-4 years old. At 5-6 years of age she showed growth retardation and deteriorating renal tubular function with bilateral... 

Daugaard G, Abildgaard U, Holstein-Rathlou NH, Bruunshuus I, Bucher D, Leyssac PP. Renal tubular function in patients treated with high-dose cisplatin. Qin Pharmacol Ther I988 44(2) 164-72. 

Anastasio P, Frangiosa A, PapaliaT, DeNapoli N, Capodicasa L, LoguercioC, DelVecchio BC, DeSanto NG. Renal tubular function by lithium clearance in liver cirrhosis. Sem Nephrol 2001 21 323-326. 

Tsukamoto N, HirabayashiY, Shimizu R, Mitsuhata H. The effects of sevoflurane and isoflurane anesthesia on renal tubular function in patients with moderately impaired renal function. Anesth Anaig 1996 82(5) 909-13. 

In general, CM attenuates both renal hemodynamics and renal tubular function [50]. Mainly demonstrated in animal models injection of CM resulted in a transient increase, followed by a more prolonged decrease in renal blood flow (RBF) [51-53]. 

Chia KS,Tan AL, Chia SE, Ong CN Jeyaratnam J. Renal tubular function of cadmium exposed workers. Ann Acad Med Singapore... 

Ohno T, Sakamoto M, Kurosawa T, et al. Total mercury levels in hair, toenail, and urine among women free from occupational exposure and their relations to renal tubular function. Environ Res 2007 103(2) 191-7. 

Naleway C, Chou HN, Muller T, et al. 1991. On-site screening for urinary Hg concentrations and correlation with glomerular and renal tubular function. J Public Health Dent 51(1) 12-17. 

Amino acid excretion in urine varies with maturation of renal tubular function. Premature infants, especially during the first week, have a generalized physiological renal aminoaciduria (see Figure 20-2) even at full term, aminoaciduria is more pronounced than in normal adults. In the urine of normal adults, glycine is usually the dominant fraction, with alanine, serine, glutamine, and— in indulgent meat eaters— histidine and 1-methylhistidine present in smaller quantities. In some normal urine, taurine is prominent in others, (3-aminoisobutyric acid is seen. 

High plasma levels occur in renal failure, inflammation, and neoplasms, especially those associated with B lymphocytes. BMG assay may be used to test renal tubular function, particularly in kidney transplant recipients in whom rejection of the allograft manifests as diminished tubular function (see Chapter 45). Serial assays of BMG are also useful to monitor B-celi tumors. In acute leukemia and lymphoma with central nervous system (CNS) involvement, the level of BMG is increased in CSF and in Sjogren s syndrome with... 

When glomerular filtration or renal tubular function is decreased, hyperkalemia may be precipitated by intravenous infusion of IC. Infusion rates in excess of 20 mmol/hr or use... 

The calcium ion liquid-membrane electrode is a valuable tool for physiological investigations because this ion plays important roles in such processes as nerve conduction, bone formation, muscle contraction, cardiac expansion and contraction, renal tubular function, and perhaps hypertension. Most of these processes are influenced more by the activity than the concentration of the calcium ion activity, of course, is the parameter measured by the membrane electrode. Thus, the calcium ion electrode (and the potassium ion electrode and others) is an important tool in studying physiological processes. 

Schoen, E. J.. Lowe s syndrome abnormalities in renal tubular function in combination with other congenital defects. Amcr. J. Med. 27, 781-792 (1959). 

Westenfelder C, Hamburger RK, Garcia ME. 1981. Effect of vanadate on renal tubular function in rats. Am J Physiol 240 F522-F529. 

Toxicity is often initially manifest by abnormahties of renal tubular function including potassium, sodium, and magnesium wasting, impaired urine concentrating ability, and distal renal tubular acidosis due to a leak of hydrogen ions back out of the tubular lumen. Substantial potassium and magnesium replacement may be necessary. Renal blood flow and GFR decreases are common, and result in a rise in serum creatinine and blood urea nitrogen concentrations. 

Infants are very vulnerable to water loss because their renal tubular function is not fully mature. In addition, they are... 

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