Tissue vitamin concentrations are maintained constant by changing the urinary excretion rate of vitamins in rats’ restricted food intake

2014 ◽  
Vol 78 (12) ◽  
pp. 2102-2109 ◽  
Author(s):  
Katsumi Shibata ◽  
Tsutomu Fukuwatari
Nature ◽  
1963 ◽  
Vol 198 (4879) ◽  
pp. 450-453 ◽  
Author(s):  
T. CHULSKI ◽  
R. H. JOHNSON ◽  
C. A. SCHLAGEL ◽  
J. G. WAGNER

1997 ◽  
Vol 16 (11) ◽  
pp. 667-672 ◽  
Author(s):  
S. Halbach ◽  
L. Kremers ◽  
H. Willruth ◽  
A. Mehl ◽  
G. Welzl ◽  
...  

The number of amalgam-covered surfaces and the occlusal area of the fillings, the concentrations of total mercury in plasma, erythrocytes and urine, the urinary excretion rate, and the absorbed daily doses estimated by two separate methods from intra-oral Hg emission were determined in 29 volunteers with a low amalgam load. The transfer ofHg from the fillings via the oral cavity and blood to urinary excretion was evaluated by multiple correla tions between these variables. In addition, the combina tion of variables most representative of the entire compartmental transfer of amalgam Hg was determined. Urinary excretion (1), Hg concentration in plasma (2) and absorbed dose (3) were most closely correlated to each other, followed by correlations with the variables of the fillings (4). Correlation coefficients were 0.75 for variables 1 vs 2 and 2 vs 3, and 0.49 for variables 3 vs 4. It was concluded that variables 1-3 best reflected the transfer of mercury from amalgam fillings throughout the organism and that they were relatively insensitive to dietary mercury. The determination of total mercury in plasma and of its urinary excretion rate appears, under practical aspects, most suitable for the investigation of Hg uptake from amalgam.


Endocrinology ◽  
2003 ◽  
Vol 144 (8) ◽  
pp. 3338-3343 ◽  
Author(s):  
Liomar A. A. Neves ◽  
Aleck F. Williams ◽  
David B. Averill ◽  
Carlos M. Ferrario ◽  
Michael P. Walkup ◽  
...  

Abstract The vasoactive effect of angiotensin (Ang)-(1–7) in mesenteric resistance arteries together with its plasma and kidney concentration and urinary excretion was assessed in pregnant and virgin rats. Mesenteric arteries (230–290 μm) were mounted in a pressurized myograph system and Ang-(1–7) concentration-dependent response curves (10−10–10−5m) were determined in arteries preconstricted with endothelin-1 (10−7m). The Ang-(1–7) response was investigated in vessels with and without pretreatment with the Ang-(1–7) antagonist [d-[Ala7]-Ang-(1–7)] (10−7m). Ang-(1–7) caused a significantly enhanced, concentration-dependent dilation of mesenteric vessels (EC50 = 2.7 nm) from pregnant compared with virgin female rats. d-[Ala7]-Ang-(1–7) eliminated the vasodilator effect of Ang-(1–7). There was no significant change in plasma concentration of Ang-(1–7) in pregnant animals. On the other hand, 24 h urinary excretion and kidney concentration of Ang-(1–7) were significantly higher in pregnant animals. The increased mesenteric dilation to Ang-(1–7) with enhanced kidney concentration and 24 h urinary excretion rate of Ang-(1–7) suggests an important role for this peptide in cardiovascular regulation during pregnancy.


1986 ◽  
Vol 251 (4) ◽  
pp. F581-F587 ◽  
Author(s):  
N. Perico ◽  
A. Benigni ◽  
C. Zoja ◽  
F. Delaini ◽  
G. Remuzzi

Animals and humans undergoing a chronic treatment with cyclosporin A (CyA) show a reduction in glomerular filtration rate (GFR). The cause of this abnormality has not been established. Since CyA interferes with arachidonic acid (AA) metabolism in various cells, we wished to determine whether alterations in renal AA metabolites contribute to deteriorating renal function in rats on CyA. We show that chronic CyA treatment induces a progressive increase in the renal synthesis of thromboxane (TX) A2. This is a selective abnormality in that CyA does not influence the renal synthesis of prostaglandin E2 (PGE2) and prostacyclin (PGI2). A significant negative correlation has been found between TXB2 urinary excretion rate and inulin clearance. No correlation has been observed between TXB2 excretion and p-aminohippuric acid clearance. The withdrawal of CyA is followed by a normalization of both TXB2 urinary excretion rate and GFR. The administration of a selective TXA2 inhibitor, UK-38,485, resulted in a significant reduction in urinary excretion of TXB2 accompanied by a significant increase in GFR. We conclude that chronic treatment with CyA in rats is associated with a selective increase in renal TXA2 synthesis and suggest that this abnormality may play a role in the reduction of GFR.


Guanidines 2 ◽  
1989 ◽  
pp. 137-146
Author(s):  
Yoshiyuki Takano ◽  
Fumitake Gejyo ◽  
Yoshio Shirokane ◽  
Moto-o Nakajima ◽  
Masaaki Arakawa

Hypertension ◽  
2014 ◽  
Vol 64 (suppl_1) ◽  
Author(s):  
AKIRA NISHIYAMA ◽  
Yoshihide Fujisawa ◽  
Abu Sufiun ◽  
Kazi Rafiq ◽  
Daisuke Nakano ◽  
...  

Proximal tubular sodium-glucose co-transporter 2 (SGLT2) transports glucose and sodium with a 1:1 stoichiometry. However, studies have indicated that treatment with SGLT2 inhibitors does not substantially increase the urinary excretion rate of sodium, while that of glucose is markedly increased. These data suggest that urinary sodium is reabsorbed by other mechanisms distal to the nephron during SGLT2 inhibition. Here, we aimed to investigate whether diuretics affect the SGLT2 inhibitor-induced changes in the urinary excretion rate of sodium in obese metabolic syndrome SHR/NDmcr-cp(+/+) (SHRcp) rats. Male 13-week-old SHRcp rats were treated with: 1) vehicle (0.5% carboxymethylcellulose), 2) a SGLT2 inhibitor, luseogliflozin (10 mg/kg/day, p.o.), 3) luseogliflozin + hydrochlorothiazide (10 mg/kg/day, p.o.) or 4) luseogliflozin + hydrochlorothiazide + furosemide (5 mg/kg/day, p.o.) for 5 weeks (n = 6-8 per group). Blood pressure and glucose metabolism were evaluated by telemetry and oral glucose tolerance test respectively. Vehicle-treated SHRcp rats developed non-dipper type hypertension (night and day time systolic blood pressure; 186 ± 2 and 185 ± 2 mmHg, respectively) and insulin resistance. As compared with vehicle-treated animals, luseogliflozin-treated rats showed an approximately 4,000-fold increase in urinary glucose excretion and improved glucose metabolism. Luseogliflozin also slightly decreased blood pressure, which was associated with an approximately 30% increase in urinary excretion of sodium. The addition of hydrochlorothiazide or hydrochlorothiazide + furosemide further decreased blood pressure and improved blood pressure circadian rhythm to a dipper profile in luseogliflozin-treated animals. In these animals, urinary sodium excretion tended to be increased by diuretics, although these changes were not statistically significant. These data indicate that SGLT2 inhibitor-induced natriuresis is not enhanced by diuretics. Thus, SGLT2 inhibitors may elicit their beneficial effects on glucose metabolism and hypertension in patients who are treated with diuretics.


2013 ◽  
Vol 34 (9) ◽  
pp. 1665-1669 ◽  
Author(s):  
Qinghao Cheng ◽  
Jiawan Wang ◽  
Anshi Wu ◽  
Rujin Zhang ◽  
Lei Li ◽  
...  

1995 ◽  
Vol 132 (6) ◽  
pp. 681-687 ◽  
Author(s):  
Masatoshi Yamazaki ◽  
Seiki Ito ◽  
Akio Usami ◽  
Nagayuki Tani ◽  
Osamu Hanyu ◽  
...  

Yamazaki M, Ito S, Usami A, Tani N, Hanyu 0, Nakagawa O. Nakamura H, Shibata A. Urinary excretion rate of ceruloplasmin in non-insulin-dependent diabetic patients with different stages of nephropathy. Eur J Endocrinol 1995;132:681–7. ISSN 0804–4643 The level of ceruloplasmin, which is a more negatively charged protein than albumin, was measured by an immunoradiometric assay in timed overnight urine and serum samples from patients with non-insulin-dependent diabetes mellitus and healthy controls. None of the plasma proteins examined showed any cross-reactivity in this assay. A linear correlation was seen between the ceruloplasmin level and the serial dilution of the sample. Western blot analysis using concentrated urine samples showed that the molecular weight of ceruloplasmin in the urine sample was the same as that of ceruloplasmin in the serum and standard samples. These findings indicated that the substance detected by this assay was truly ceruloplasmin. The urinary ceruloplasmin excretion rate (CER) and clearance of ceruloplasmin increased in parallel with the progression of albuminuria. The highest CER was found in macroalbuminuric patients, followed by micro- and normoalbuminuric patients and the healthy control subjects, the differences between the groups being significant. In view of the fact that the isoelectric point of ceruloplasmin (4.4) is more acidic than that of albumin, the present findings suggested that an enhanced CER was due either to the alteration of charge selectivity in the glomerular basement membrane with unaltered tubular function or to a defect of the non-discriminatory pores (shunt pathway) with unaltered tubular function. Seiki Ito, Division of Gerontology, Akita University Hospital, 1-1-1 Hondou, Akita City, Japan 010


1982 ◽  
Vol 206 (3) ◽  
pp. 461-465 ◽  
Author(s):  
A B S J Dawnay ◽  
C Thornley ◽  
W R Cattell

A rapid, specific radioimmunoassay has been used to measure Tamm-Horsfall glycoprotein (TH glycoprotein) in urine. The apparent concentration increased with increasing dilution of urine in water, reaching a plateau at 1 in 20. This increase was greater the higher the osmolality and TH glycoprotein concentration and the lower the pH of the original sample. A dilution of 1 in 100 was chosen for routine assay. Whole urine was centrifuged and the dissolved precipitate and supernatant assayed to quantify the proportion of TH glycoprotein of TH glycoprotein initially present in highly aggregated form. This correlated positively and significantly with increasing osmolality, decreasing pH and increasing TH glycoprotein concentration. When the urine was diluted 1 in 100 in water, no TH glycoprotein was precipitated by centrifugation and the measured concentrations were unaffected by alterations of urine pH or calcium concentration or by addition of sodium dodecyl sulphate. Parallelism was demonstrated between the diluted samples and the disaggregated standard preparation. Recovery of added standard to diluted urine varied between 96 and 114%. The apparent concentration of TH glycoprotein in neat or diluted urine was not affected by freezing or by storage at 4 degrees C or room temperature for at least 2 days. A physiological range for the urinary excretion rate was established as 22-56 mg/24 h, based on samples from 29 individuals with normal renal function, as defined by their creatinine clearance. There was no significant correlation between serum concentrations of TH glycoprotein and its urinary excretion rate, nor between urinary excretion rate and creatinine clearance.


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