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At least 91 records · Page 5Linked to original sources
PubMed1988

Disturbed relationship between urinary prostaglandin E2 excretion, plasma arginine vasopressin and renal water excretion after oral water loading in early hepatic cirrhosis.

An oral water load of 20 ml kg-1 body weight was given to 11 patients with early hepatic cirrhosis and to 16 healthy control subjects. Urinary output (V), free water clearance (CH2O), urinary excretion of prostaglandin E2 (PGE2) and F2 alpha (PGF2 alpha), and plasma concentration of arginine vasopressin (AVP) were determined before and during the first 4 h after loading. During basal conditions, PGE2 excretion was the same in patients (75 pg min-1, median, range 15-569) and controls (78 pg min-1, range 22-262), but during the first hour after water loading, PGE2 increased to a significantly higher level in cirrhotic patients (423 pg min-1, median) than in control subjects (162 pg min-1) (P less than 0.05). No difference in PGF2 alpha excretion was found between the two groups. Urinary output and CH2O were significantly lower after water loading in patients than in controls. Arginine vasopressin before water loading did not differ between patients and control subjects, but after loading it was unchanged in the patients, whereas a significant reduction (1.9 to 1.4 pmol l-1, P less than 0.01) was found in the control subjects. In controls, but not in patients, PGE2 was significantly positively correlated to V and CH2O, and negatively correlated to AVP after water loading. Thus, renal PGE2 excretion is increased and CH2O is decreased after water loading in patients with early hepatic cirrhosis, and a disturbed relationship seems to exist between PGE2 on the one hand, and AVP and renal water excretion, on the other, in these patients after water loading.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1961

Excretion and re-excretion of a broad-spectrum penicillin in bile.

A technique is described for estimating the biliary excretion, reabsorption and re-excretion of an antibacterial drug in rats. D(-)-6-(alpha-Amino-alpha-phenylacetamido)-penicillanic acid (BRL 1341) is rapidly excreted and re-excreted in the bile, in concentrations bactericidal to Salmonellae and other organisms which are usually refractory to antibacterial drugs in this situation. Recoveries of the drug accounted for 20 to 30% of oral of parenteral doses; much of the remainder is probably destroyed in the gut. Results from one patient indicate that D(-)-6-(alpha-amino-alpha-phenylacetamido)-penicillanic acid is excreted in high concentration also in human bile.

Ampicillin↗
PubMed1982

Circadian rhythms of urinary excretion: the relationship between the amount excreted and the circadian changes.

1. The circadian rhythms of urinary excretion of water, sodium, chloride, potassium, urate, calcium and phosphate have been studied in several groups of volunteers. 2. These rhythms have been measured: under nychthemeral and constant routine regimens; while subjects were in an Isolation Unit or allowed free egress into society; with spontaneous changes in dietary intake; or after potassium-loading. 3. A direct relationship between 24 h mean rate of excretion and range of excretion was found in all circumstances and for all variables; this relationship was found also when the mesor and amplitude of the cosine curve best describing each 24 h of data were considered. 4. These relationships derive from the observation that, with increases in 24 h mean rates of excretion, nocturnal rates increased less than diurnal rates. 5. This differential sensitivity as between the night and day times has both endogenous and exogenous components. 6. It is suggested that circadian rhythms of urinary excretion result at least partially from this differential sensitivity of the kidney to homeostatic control mechanisms.

Adolescent↗
PubMed1988

Intersalt: an international study of electrolyte excretion and blood pressure. Results for 24 hour urinary sodium and potassium excretion. Intersalt Cooperative Research Group.

The relations between 24 hour urinary electrolyte excretion and blood pressure were studied in 10,079 men and women aged 20-59 sampled from 52 centres around the world based on a highly standardised protocol with central training of observers, a central laboratory, and extensive quality control. Relations between electrolyte excretion and blood pressure were studied in individual subjects within each centre and the results of these regression analyses pooled for all 52 centres. Relations between population median electrolyte values and population blood pressure values were also analysed across the 52 centres. Sodium excretion ranged from 0.2 mmol/24 h (Yanomamo Indians, Brazil) to 242 mmol/24 h (north China). In individual subjects (within centres) it was significantly related to blood pressure. Four centres found very low sodium excretion, low blood pressure, and little or no upward slope of blood pressure with age. Across the other 48 centres sodium was significantly related to the slope of blood pressure with age but not to median blood pressure or prevalence of high blood pressure. Potassium excretion was negatively correlated with blood pressure in individual subjects after adjustment for confounding variables. Across centres there was no consistent association. The relation of sodium to potassium ratio to blood pressure followed a pattern similar to that of sodium. Body mass index and heavy alcohol intake had strong, significant independent relations with blood pressure in individual subjects.

Adult↗
PubMed1977

The diurnal urinary excretion of oxalate and the effect of pyridoxine and ascorbate on oxalate excretion.

The diurnal urinary oxalate excretion has been determined in 11 patients with urolithiasis and in 7 normal subjects. Increased excretion following meals was observed. The variation from hour to hour was most pronounced in the stone patient group. The relation between oxalate concentration and urinary volume was found to follow a biphasic exponential course. Pyridoxine administration increased oxalate excretion in 9 out of 12 subjects and decreased the excretion in 3 subjects. Ascorbate administration increased oxalate excretion in all 7 subjects studied.

Ascorbic Acid↗
PubMed1994

NITROGENOUS EXCRETION IN THE TERRESTRIAL CARNIVOROUS CRAB GEOGRAPSUS GRAYI: SITE AND MECHANISM OF EXCRETION

The rate and mechanism of nitrogen excretion were examined in Geograpsus grayi. This species excretes waste nitrogen as gaseous NH3 in periodic bursts. The mean concentration of total ammonia ([NH3]+[NH4+]) in the primary urine during bursts of excretion (1.72 mmol l-1) was similar to that of haemolymph (2.07 mmol l-1) but was significantly lower (P<0.005) than that of branchial fluid (80.6 mmol l-1). The effects of ion exchange inhibitors on the apical membrane of the gill epithelium in Geograpsus grayi were examined. The presence of an amiloride-sensitive Na+/NH4+ exchanger was confirmed and a SITS-sensitive Cl- influx suggested Cl-/HCO3- exchange. Thus, the site of nitrogenous excretion in this species is the branchial chamber, which is also the site of reprocessing of urine for ion regulation in other terrestrial crabs. Gaseous ammonia excretion is achieved by volatilisation of NH3 from the branchial fluid. High partial pressures of ammonia in the branchial fluid are produced by apical Na+/NH4+ exchange and elevation of the pH.

Journal Article↗
PubMed1985

Iodine intake of Japanese male university students: urinary iodine excretion of sedentary and physically active students and sweat iodine excretion during exercise.

We examined the urinary iodine excretion of sedentary and physically active male university students in order to estimate the iodine intake of Japanese. Iodine excretion in sweat collected during treadmill exercise was also determined in different dietary iodine levels. The mean urinary iodine excretion of 5 sedentary students during 15 consecutive days was 357 micrograms/day (40-3,390). When high-iodine food, i.e. seaweed, was included in meals in only 22% of the total experimental days of 5 subjects, the urinary iodine excretion was high (1,106 micrograms/day, 298-3,390), but was low (153 micrograms/day, 40-441) when seaweeds were not consumed. An unexpectedly low mean urinary iodine excretion of 149 micrograms/day (50-393) was found in 10 rowing club students during 6 consecutive days of their summer training camp, probably being due to iodine losses in sweat; sweat iodine concentrations were about 37 micrograms per liter, regardless of serum and urinary iodine levels modulated by the dietary iodine level. The present data indicate that the iodine intake of Japanese depends on the amount of seaweed consumption and that it is not necessarily as high as expected from the data obtained in the 1960s. Moreover, our findings indicate the importance of taking account of iodine loss in sweat in the evaluation of iodine nutrition for physically active persons working in hot and humid environments.

Adult↗
PubMed1975

[Experimental studies on absorption, distribution and excretion of fosfomycin. I. Absorption distribution and excretion of fosfomycin calcium salt (author's transl)].

In order to develop some oral drug preparations containing calcium salt of fosfomycin ((minus)-cis-1,2-epoxypropylphosphonic acid) which is a new antibiotic, the absorption, distribution and excretion were studied when it was administered orally to fasted test animals such as rats, rabbits and dogs. The results are as follows: 1) In the case of rats, the more dose size was increased, the more ratio of excretion in urine as index of gastrointestinal absorption was reduced and ratio of excretion in stools was adversely increased, which suggested a decrease in absorption efficiency. But, as absolute amount of excretion in urine became larger with dose size, it was considered that increase in dose size would serve for elevation of serum levels. 2) When the calcium salt was given to rats and rabbits in form of solution and suspension, the former was more eminent than the latter regarding to absorption efficiency, as generally known. The solution, however, needed relatively large quantity of water to solubilize the calcium salt, and it was not considered that the absorption efficiency depends on only dissolution step or dissolution rate. 3) Difference of the particle size varying from 1.50 mu(bulk particle size) and 0.64 mu(mechanical limit size) measured by Kozeny-Carman method did not affect on the absorption in rats and dogs. So it was considered that the bulk could be use directly without micronizing in manufacturing process for the oral preparations. 4) There were some differences of absorption among the animal species. Good absorption was shown in turn in rats, dogs and rabbits. These differences might depend not only on physiological factors but also anatomical differences such as length of gastrointestinal tract. 5) In rabbits high concentration was observed successively in kidney, lung, heart and so on. In any organ its level decreased similarly to the serum level, not sustaining its initial high concentration. The calcium salt did not possess any affinity to certain organs. 6) In conclusion, though some differences of gastrointestinal absorption were observed among the animal species, fosfomycin calcium salt was well absorbed without problem of micronizing the bulk particles. Moreover, it was perceived that fosfomycin calcium salt, once distributed, would not remain in particular organs, being excreted out of body.

Administration, Oral↗
PubMed1989

[Effect of electroacupuncture on the urine flow, sodium excretion and potassium excretion in the conscious dog].

Unanesthetized dogs with chronic ureteral and gastric fistulae were infused with 0.8% NaCl solution into the stomach at a constant rate for maintaining a state of saline loading. In these animals, there was a steady renal excretion of water, sodium and potassium. However, after a 20-minute unilateral electroacupuncture of the points corresponding to "Sanyinjao" and "Zhaohai" in human leg as described in Traditional Chinese Medicine caused a marked increase in urine flow and urinary sodium excretion, but had no significant effect on urinary potassium excretion. In another group of normal unanesthetized dogs (without saline loading), the effect of electroacupuncture mentioned above no longer appeared. Owing to the facts that electroacupuncture merely increased the water and sodium excretion of kidneys in saline-loading unanesthetized dogs, and had no effect in normal unanesthetized dogs, it is concluded that the effects of electroacupuncture on the urine flow and sodium excretion in saline-loading unanesthetized dogs is an action of normalization by acupuncture.

Animals↗
PubMed1988

Excretion of digoxin-like immunoreactivity in urine of normal subjects: correlations with excretion of creatinine and electrolytes.

To verify whether there is a variation in the 24-h urinary excretion of digoxin-like immunoreactivity (DLIS) in humans, we studied 18 normal adults, who collected their urines for 24-h in several portions. We then measured DLIS (by means of a sensitive RIA method), creatinine, sodium, and potassium concentrations in the urine samples. The mean urinary excretion rate for DLIS in the complete 24-h collection was 84.8 (SD 31.3) pg/min. The mean DLIS urinary excretion rate calculated for overnight collections was significantly lower than those of afternoon collections (P less than 0.01) and the 24-h collection (P less than 0.05). Significant positive correlations were found between urinary DLIS and excretion rates for creatinine (r = 0.347, P = 0.0016), Na+ (r = 0.232, P = 0.038), and K+ (r = 0.323, P = 0.003), respectively. Our data suggest that urinary excretion of DLIS is higher during "active" hours of the day, especially in the afternoon, than at rest, during the night.

Adult↗
PubMed1984

[Distribution, metabolism and excretion of 14C-MT-141 in rats. I. Distribution, metabolism and excretion after single intravenous administration in male rats].

The distribution, metabolism and excretion of the radioactivity were studied in male rats after the bolus intravenous administration of 14C-MT-141. The biological half-lives obtained from the blood concentration-time curve were 0.43 hour for the data in the first 4 hours and 16.5 hours for the data from 6 hours to 24 hours after the intravenous administration of 14C-MT-141. The radioactivity was excreted mainly into urine, and the cumulative urinary and fecal excretion of the radioactivity were 75.2% and 24.1% of the dose, respectively, within 120 hours after the intravenous administration of 14C-MT-141. The cumulative biliary excretion of the radioactivity was 18% of the dose within 48 hours after the intravenous administration, and 35% of the radioactivity excreted into bile (about 6% of the dose) was reabsorbed from the intestine. The highest concentration of the radioactivity was observed in the kidneys, and also the relatively high concentrations were observed in the liver, plasma and intestine, while the concentrations in the brain, fat and muscle were low. Within 24 hours after the intravenous administration of 14C-MT-141, the radioactivity in the highly distributed organs or tissues was decreased to less than 3% of the values at 5 minutes after the intravenous administration. A small amount of N-acetyl-MT-141 was found in urine and feces as a metabolite.

Animals↗
PubMed1997

Biliary excretion of pravastatin in rats: contribution of the excretion pathway mediated by canalicular multispecific organic anion transporter.

The biliary excretion of pravastatin in normal rats and Eisai hyperbiliruminemic rats (EHBRs) was examined in vivo and in vitro using bile canalicular membrane vesicles (CMVs). In vivo, the total body clearances at steady-state (CLtot) for both rat strains decreased as the infusion rate increased. At the lowest infusion rate, CLtot for normal rats was 1.6 times higher than that for EHBRs. Under this set of conditions, the biliary excretion clearance (CLbile), defined as the biliary excretion rate at steady-state divided by the concentration in the liver (Cliver), for normal rats was 3-fold higher than that for EHBRs. The CLbile fell markedly with increasing Cliver for normal rats and the Michaelis constant (KM) for Cliver was 180 microM; in contrast, the degree of saturation was slight if any in EHBRs. In vitro, the uptake of pravastatin by CMVs prepared from normal rats exhibited clear ATP-dependence, whereas only a minimal effect of ATP was observed on the uptake by CMVs from EHBRs. Transport kinetic studies were performed over a wide range of pravastatin concentration (0.2-10,000 microM) with a tracer tritium-labeled pravastatin. Saturation was observed both in the ATP-dependent (KM: 220 microM) and ATP-independent (KM: 480 microM) uptake by CMVs prepared from normal rats. ATP-dependent uptake of 2, 4-dinitrophenyl glutathione, a typical substrate for the canalicular multispecific organic anion transporter (cMOAT), was inhibited by pravastatin in a concentration-dependent manner and the resultant inhibitory constant of pravastatin (170 microM) was comparable with the KM value of ATP-dependent pravastatin uptake itself. In conclusion, biliary excretion of pravastatin is mediated mainly by cMOAT in normal rats. This can explain the decrease in the biliary excretion of pravastatin in EHBRs.

Animals↗
PubMed2004

Effects of peritoneal injection of NH4HCO3 on nitrogen excretion and metabolism in the swamp eel Monopterus albus-- increased ammonia excretion with an induction of glutamine synthetase activity.

Monopterus albus has to deal with high environmental ammonia concentrations during dry seasons and agricultural fertilization in rice fields. In this study, NH4HCO3 (10 micromol per g fish) was injected into the peritoneal cavity of M. albus, raising the level of ammonia in the body, in order to elucidate the strategies involved in defense against the toxicity of exogenous ammonia. During the subsequent 24 h after NH4HCO3 injection, there was a significant increase in the ammonia excretion rate, which indicates that the main strategy adopted by M. albus was to remove the majority of the exogenous ammonia through enhanced ammonia excretion. Exogenous ammonia was not detoxified into urea for excretion or accumulation. Six hours post-injection of NH4HCO3, ammonia content in the tissues built up significantly, especially in the brain, which suggests that M. albus had high tolerance of ammonia toxicity at the cellular and sub-cellular levels. By hour 12 post-injection, there were significant increases in the activities of glutamine synthetase in the muscle, liver, and gut, accompanied by significant increases in glutamine contents in the muscle and the liver. There was also a significant increase in the glutamine content in the brain at hour 6 post-injection of NH4HCO3. These results confirm the capability of M. albus to detoxify ammonia through glutamine synthesis. Overall, injection of NH4HCO3 had only minor effects on the contents of FAAs, other than glutamine, in tissues of M. albus because the majority (70%) of the injected ammonia was excreted within the 24-h period.

Ammonia↗
PubMed1977

Iodipamide kinetics: capacity-limited biliary excretion with simultaneous pseudo-first-order renal excretion.

Iodipamide was infused into three dogs with bile fistulas to achieve various steady-state blood levels. When using ultracentrifugation techniques, iodipamide was found to be highly bound to plasma protein. The total blood clearance was low relative to hepatic blood flow. For either the whole blood concentration or the unbound concentration of iodipamide, the biliary excretion was shown to be capacity limited with a transport maximum, Tm, of approximately 1.0mumole/kg/min. The steady-state renal excretion rate, plotted against the whole blood concentration of iodipamide, resulted in a concave ascending curve, which could lead to the false conclusion that iodipamide was undergoing active renal tubular reabsorption. However, when corrected for plasma protein binding, a linear relationship was obtained, suggesting that the renal excretion of iodipamide is a pseudo-first-order process. The Michaelis-Menten parameters for the extrarenal elimination, when calculated using the whole blood concentration of iodipamide, led to a similar discrepancy compared to the parameter estimates obtained from biliary excretion rate data. This discrepancy can be eliminated when one uses the unbound concentration of iodipamide in the parameter estimates.

Animals↗
PubMed1988

Urinary excretion of 1,5-anhydro-D-glucitol accompanying glucose excretion in diabetic patients.

The urinary excretion of 1,5-anhydro-D-glucitol, a pyranoid polyol, in humans was studied. The plasma of nondiabetic human subjects contained high concentrations of this polyol (greater than 110 mumol/l), and there was a tendency for the 24-h excretion of it to become more variable in direct proportion to its plasma concentration. In contrast, diabetic patients showed lower plasma concentrations of this polyol, and the variation in the 24-h excretion of 1,5-anhydro-D-glucitol was especially notable among the patients with an extremely low plasma concentration of the polyol. This diabetic group showed a statistically significant correlation (p less than 0.01), between the urinary 1,5-anhydro-D-glucitol and urinary glucose. This correlation was more markedly demonstrated during a 100-g oral glucose tolerance test: parallel changes were observed in the concentrations of 1,5-anhydro-D-glucitol and glucose in the urine collected every hour after the glucose load. These observations led to the proposal that low plasma concentration of this polyol, which is observed in diabetes mellitus, may be the result of a frequent and/or prolonged high blood glucose concentration beyond the renal threshold for glucose excretion.

Adult↗
PubMed1981

Urinary excretion of immunoreactive vasopressin in prepubertal children. Lack of correlation with urinary excretion of immunoreactive neurophysins.

The excretion of immunoreactive vasopressin (AVP) and neurophysins was determined in 24 h urine samples from 62 normal healthy children of various ages. Five groups of children were selected: group I (n = 7, aged 2 to 3 years), group II (n = 13, aged 3 to 5 years), group III (n = 16, aged 5 to 7 years), group IV (n = 16, aged 7 to 9 years), group V (n = 10, aged 9 to 11 years). The method used for urine AVP determination consisted of an extraction using a procedure slightly modified from that of Miller and Moses [14], coupled to a radioimmunoassay. The following urinary AVP excretions were obtained: group I mean: 70.8 ng/m2/24 h range: 51-150 ng, group II mean: 54.1 ng/m2/24 h range: 17-113.6 ng, group III mean: 55.2 ng/m2/24 h range: 18-106 ng, group IV mean: 39.9 ng/m2/24 h range: 11.7-77.9 ng, group V mean: 39.4 ng/m2/24 h range: 25.8-64 ng. The excretion of AVP was significantly correlated to the daily urinary osmolality (P less than 0.001) whether expressed in ng/24 h (r = 0.41) o rin ng/m2/24 h (r = 0.4.7). Neurophysins excretion ranging between 7 and 1,278 ng/24H is too variable to allow interpretation.

Age Factors↗
PubMed1999

Silicic acid: its gastrointestinal uptake and urinary excretion in man and effects on aluminium excretion.

Silicon (Si), as silicic acid, is suggested to be the natural antidote to aluminium (Al) toxicity, and was recently shown to promote the urinary excretion of Al from body stores. The metabolism of Si in man, however, remains poorly investigated. Here we report on the pharmacokinetics and metabolism of Si in healthy volunteers following ingestion of orthosilicic acid (27-55 mg/l Si) in water. We also investigated whether orthosilicic acid promotes the urinary excretion of endogenous Al. Minimum, median uptake of Si from the ingested dose was 50.3% (range: 21.9-74.7%, n = 8) based on urinary analysis following dosing. Significant correlations were observed between creatinine clearance and Si levels in serum or urine (r = 0.95 and 0.99, respectively). Renal clearance of Si was 82-96 ml/min suggesting high renal filterability. These results suggest that orthosilicic acid is readily absorbed from the gastrointestinal tract of man and then readily excreted in urine. There was no significant increase in Al excretion, over 32 h, following ingestion of the orthosilicic acid dose (P = 0.5; n = 5).

Adult↗
PubMed1988

Relation between renal and hepatic excretion in drugs. VIII. Influence of triiodothyronine on maturation of phenol red excretion in rats.

Experiments were performed on 10-, 20-, and 55-day-old female rats. Administration of triiodothyronine (T3; 10 or 20 micrograms/100 g b.wt. for 3 days, once daily) was followed by a significant increase in renal phenol red excretion in 20-day-old and older rats. In 10-day-old rats there was no stimulatory effect of T3 on renal excretion of the dye. On the other hand, biliary excretion of phenol red was significantly diminished in all age groups. Surprisingly, in nephrectomized rats there was a significant increase in hepatic dye excretion in 20- and 55-day-old rats after T3. This increase in transport capacity via liver was connected with a distinct rise of bile flow. In experiments on tissue slices phenol red accumulation was investigated at different medium concentrations. In renal cortical slices there was no significant influence of T3 on specific accumulation of phenol red per 1 g organ wet weight, whereas aerobic accumulation of the dye seems to be diminished in liver tissue after T3 treatment. But in all age groups kidney weight increased significantly. Calculation of total accumulation (= specific accumulation x organ wet weight) resulted in a significantly enhanced renal transport capacity for phenol red in all age groups. In contrast, total hepatic accumulation was reduced independently of age.

Aging↗