Quantification of human angiotensinogen by a novel sandwich ELISA

The urinary angiotensinogen excretion rates show a clear relationship to kidney angiotensin II content, suggesting that urinary angiotensinogen may serve as an index of angiotensin II-dependent hypertensive rats. However, simple and accurate methods to measure human angiotensinogen are unavailable at this time. We have developed two antibodies and a sensitive and specific quantification ELISA system for human angiotensinogen to be applicable to human subjects. The ELISA is able to detect human angiotensinogen at range of 0.01-1 microg/well (R(2)=0.9945) using standard ELISA plates. This ELISA will be a useful tool to investigate the relationship between urinary angiotensinogen excretion rates and reactivity to antihypertensive drugs in hypertensive human subjects.     

The pattern of urinary excretion of corticosteroids in Rhesus monkeys (Macaca mulatta).

Urinary total 17-oxogenic steroids (17-OGS), cortisol, cortisone, corticosterone, tetrahydrocortisol (THF), allo-tetrahydrocortisol (all-THF), tetrahydrocortisone (THE), cortols and cortolones, were estimated by established methods in 30 female and 20 male rhesus monkeys. The pattern of the excretion of these steroids in this species was comparable with the human corticosteroids excretion, irrespective of sex difference. The results obtained from this investigation show that they could be used during the study of adrenocortical function and cortisol metabolism in this species.     

Stimulation of ammonium ion excretion in the toad urinary bladder by an extract of human urine.

It is well known that ammonium ion excretion is increased during metabolic acidosis in mammals. The purpose of this study was to determine whether we could isolate from human urine during metabolic acidosis a factor that would stimulate NH+4 and/or H+ excretion in toad urinary bladder. Extracts of urine from six human subjects collected during NH4Cl-induced acidosis were prepared. These extracts were tested for their effect on NH+4 excretion in hemibladders mounted between plastic chambers. The extracts significantly increased NH+4 excretion in the toad urinary bladder. We found no effect on H+ excretion by these extracts. This ammoniuretic activity was not present in the urine when the same individuals were in metabolic alkalosis. We conclude that during metabolic acidosis a humoral factor is present which stimulates the excretion of NH+4. The factor could act as a permease in the bladder cell or as a stimulator of an NH+4 transport system.     

Validation and Assessment of Three Methods to Estimate 24-h Urinary Sodium Excretion from Spot Urine Samples in Chinese Adults

24-h urinary sodium excretion is the gold standard for evaluating dietary sodium intake, but it is often not feasible in large epidemiological studies due to high participant burden and cost. Three methods—Kawasaki, INTERSALT, and Tanaka—have been proposed to estimate 24-h urinary sodium excretion from a spot urine sample, but these methods have not been validated in the general Chinese population. This aim of this study was to assess the validity of three methods for estimating 24-h urinary sodium excretion using spot urine samples against measured 24-h urinary sodium excretion in a Chinese sample population. Data are from a substudy of the Prospective Urban Rural Epidemiology (PURE) study that enrolled 120 participants aged 35 to 70 years and collected their morning fasting urine and 24-h urine specimens. Bias calculations (estimated values minus measured values) and Bland-Altman plots were used to assess the validity of the three estimation methods. 116 participants were included in the final analysis. Mean bias for the Kawasaki method was -740 mg/day (95% CI: -1219, 262 mg/day), and was the lowest among the three methods. Mean bias for the Tanaka method was -2305 mg/day (95% CI: -2735, 1875 mg/day). Mean bias for the INTERSALT method was -2797 mg/day (95% CI: -3245, 2349 mg/day), and was the highest of the three methods. Bland-Altman plots indicated that all three methods underestimated 24-h urinary sodium excretion. The Kawasaki, INTERSALT and Tanaka methods for estimation of 24-h urinary sodium excretion using spot urines all underestimated true 24-h urinary sodium excretion in this sample of Chinese adults. Among the three methods, the Kawasaki method was least biased, but was still relatively inaccurate. A more accurate method is needed to estimate the 24-h urinary sodium excretion from spot urine for assessment of dietary sodium intake in China.     

The Effects of Arid Region Conditions on the Hormonal Status of Humans

The human hormonal status and its circadian and circannual rhythms that provide a background for human activities and diseases were studied under conditions of the extremely continental climate of the arid region with a long period of elevated ambient temperatures. Age- and sex-related features, biological rhythms (seasonal and circadian), and the dependence on the work specificity were studied for the activities and interrelations of the adrenal cortex, thyroid gland, and catecholamines. The peripheral blood plasma levels of the hormones and the urinary excretion of the hormone metabolites were determined by conventional methods. The findings show that the hormonal status depended on both the climatic and occupational conditions.     

Evaluation of Methods for Isolating Salmonella and Arizona Organisms from Pet Turtles

Two methods for isolating Salmonella and Arizona organisms from turtles, blending and excretion, were evaluated, and the percentage of isolates obtained by each method was compared with the percentage of isolates obtained by culture of turtle organs. The blending and excretion methods were equally effective in detecting the overall incidence of Salmonella and Arizona infections in turtles. The percentage of isolates obtained by specific organ culture, however, was less than the percentage obtained by the other two methods. The blending method detected a greater number of turtles with Arizona infections than did the excretion method, but there was no difference in the number of Salmonella infections detected by the two methods. The frequency of isolation of Arizona organisms from organs other than the small intestine and colon was higher than that of Salmonella.     

Gene suture--a novel method for intramuscular gene transfer and its application in hypertension therapy

In this report, reporter gene beta-galactosidase (LacZ) was chosen to compare two different intramuscular gene transfer methods, direct injection and gene suture. Evidence showed that gene suture can produce a higher foreign gene express efficiency in skeletal muscle compared with the direct injection method. The highly efficient eukaryotic expressing vectors of human atrial natriuretic factor (ANF) were constructed (pcD2/pAdVAntage/hANF and pcDNA3/hANF), and in vivo ANF gene delivery was performed by intramuscular gene suture. The effects of ANF gene transfer on blood pressure and renal sodium and water excretion were studied in three models of hypertensive animals. Results showed that a marked decrease of mean arterial pressure (MAP) and a significant increase of urine volume and urinary sodium excretion was produced in rats receiving the hANF construct due to the local expression of ANF and its secretion into plasma. Taken together, these results indicate that gene suture may represent a novel gene delivery modality in gene therapy.     

Aluminium in human sweat

It is of burgeoning importance that the human body burden of aluminium is understood and is measured. There are surprisingly few data to describe human excretion of systemic aluminium and almost no reliable data which relate to aluminium in sweat. We have measured the aluminium content of sweat in 20 healthy volunteers following mild exercise. The concentration of aluminium ranged from 329 to 5329 μg/L. These data equate to a daily excretion of between 234 and 7192 μg aluminium and they strongly suggest that perspiration is the major route of excretion of systemic aluminium in humans.     

Validation of a reference ELISA for estrone glucuronide using urine samples normalized by dilution to a constant rate of urine production

A direct enzyme linked immunosorbent assay (ELISA) system has been optimized as a reference method for the measurement of first statistically significant rises in estrone glucuronide excretion rates in human urine by analysing samples pre-diluted at the time of the collection by the women subjects to a constant urine production rate of 150 mL/h. Validation was achieved by correlation of the individual menstrual cycle profiles with the corresponding estrone glucuronide excretion rates determined by radioimmunoassay (RIA) on the same urine samples for a total of 221 samples from nine cycles. The pre-dilution procedure removed random variations due to fluctuations in the daily rate of urine excretion and minimized between sample matrix effects. When the ELISA data were correlated with the RIA data, Deming regression gave a slope of 1.20+/-0.03 and an intercept of 4.6+/-1.8 nmol/24h (r=0.944) and a random experimental error of 14.2 nmol/24h. The major difference in the measurements was a proportional error of 20%, which was present in either the ELISA or RIA methods or in both. Comparison of the standard normal variate transformation of the ELISA and RIA data gave hormonal profiles of the individual menstrual cycles (N=9) that overlapped almost perfectly. Statistically significant rises or falls in the magnitude of the excretion rate in one profile were mirrored faithfully in the other.     

Stimulation of ammonium ion excretion in the toad urinary bladder by an extract of human urine

It is well known that ammonium ion excretion is increased during metabolic acidosis in mammals. The purpose of this study was to determine whether we could isolate from human urine during metabolic acidosis a factor that would stimulate NH₄⁺ and/or H⁺ excretion in toad urinary bladder. Extracts of urine from six human subjects collected during NH₄Cl-induced acidosis were prepared. These extracts were tested for their effect on NH₄⁺ excretion in hemibladders mounted between plastic chambers. The extracts significantly increased NH₄⁺ excretion in the toad urinary bladder. We found no effect on H⁺ excretion by these extracts. This ammoniuretic activity was not present in the urine when the same individuals were in metabolic alkalosis. We conclude that during metabolic acidosis a humoral factor is present which stimulates the excretion of NH₄⁺. The factor could act as a permease in the bladder cell or as a stimulator of an NH₄⁺ transport system.     

Excretion of non-conjugated androstenedione and testosterone in human urine.

A method for the measurement of unconjugated testosterone and androstenedione in human urine is described. The method uses chromatographic separation followed by radioimmunoassay and has been examined for reliability. The mean 24-hour excretion of androstenedione by adult male subjects was 2.5 mug and of testosterone was 0.8 mug. For women, the mean excretion was 2.9 mug of androstenedione and 0.25 mug of testosterone. In pregnancy, androstenedione excretion was occasionally elevated above the normal range, but testosterone excretion was quite commonly increased. Some hirsute subjects exhibited an increase in androstenedione excretion, which was decreased by administration of dexamethasone. The results suggest that the amount of unconjugated testosterone in urine is not a direct reflection of the plasma free testosterone, but urinary androstenedione may be a useful reflection of plasma androstenedione levels.     

Melatonin excretion of man and rats: Effect of time of day,sleep, pinealectomy and food consumption

Pineal function was assessed in human subjects by measuring the excretion of melatonin. The hormone was extracted from the urine by adsorption on a nonionic polymeric resin and then elution with organic solvents; its concentration was determined with a bioassay based ontthe dermal melanophore response of larval anurans to melatonin in their bathing medium. Melatonin excretion among healthy, adult volunteers was 5- to 7-fold greater during the hours of sleep, darkness, and recumbancy (23:00–07:00 h) than during the active, waking hours (07:00–15:00 h or 15:00–23:00 h). When 2 subjects slept only during the daylight at odd, 8-hour intervals, their melatonin excretion was also greatest during their time of sleep. Three bedfast fracture patients (for whom sleep data were not available) failed to display melatonin rhythms. A new radioimmunoassay for melatonin was investigated in preliminary studies with experimental animals and was found to be expedient and sensitive; it was not as specific as the bioassay, however. Both analytical methods were used in studies on intact and pinealectomized rats, and the findings suggest that rhythmic melatonin excretion persists (although at a reduced amplitude) in the absence of the pineal. Fasting in the pinealectomized animal abolished the day/night variation in urinary melatonin, but did not have this effect in intact rats.     

Measurement of thyroid stimulating hormone (TSH) in human urine

Using a highly sensitive and specific immunoradiometric assay kit for human TSH, we measured TSH concentrations in unprocessed urines in normal subjects, in patients with primary hypothyroidism, and patients with renal disease. In five of ten normal subjects TSH was detectable in urine samples (less than 20-69 microU/day). In five patients with hypothyroidism, the urinary TSH excretion was increased. In seven out of ten patients with nephrotic syndrome, eight out of nine patients with chronic renal failure and two patients with tubular dysfunction, the urinary TSH excretion was increased. The urinary TSH excretion correlated significantly with both urinary protein excretion and urinary beta 2-microglobulin excretion. These results suggest that the renal handling of TSH involves both glomerular filtration and tubular re-absorption, and that urinary TSH excretion is increased when serum TSH is increased and either glomerular or tubular function is impaired.     

Excretion of DNA by purified human lymphocyte subpopulations.

A large proportion of DNA synthesized in vitro by human lymphocytes stimulated with plant mitogens or specific antigens is selectively excreted from the cells. To determine if DNA excretion differs among various types of lymphocytes, we examined purified human lymphocyte subpopulations for DNA synthesis and excretion in response to stimulation by L-PHA. The relative proportion of newly synthesized DNA that is excreted by unseparated mononuclear cells, macrophage-depleted cells, T, and B lymphocytes is identical despite great differences in the magnitude of their responses. Low levels of both DNA synthesis and excretion by macrophage-depleted cells and B cells can be increased by reconstitution with macrophages and T cells, respectively. These data indicate that DNA exretion is a general property of lymphocytes stimulated to undergo DNA synthesis by plant mitogens.     

Urinary excretion of unconjugated and conjugated 3,5-diiodothyronine

A radioimmunoassay for the estimation of 3,5-diiodothyronine (3,5-T2) in human urine has been established. The urinary excretion of both glucuronide and sulfate conjugates of 3,5-T2 were estimated after enzymatic deconjugation. In 19 healthy controls the median excretion of unconjugated 3,5-T2 was 276 pmol/d, whereas the median excretion of glucuronidated and sulfated 3,5-T2 in 7 healthy subjects was 448 and 451 pmol/d, respectively. The median excretion of 154 pmol/d in 9 hypothyroid patients did not differ from that found in controls. In contrast 12 patients with hyperthyroidism had an enhanced excretion, 1312 pmol/d (P less than 0.01). Compared with previous data on the daily degradation of 3,5-T2, it is concluded that approximately one-sixth of degradated 3,5-T2 is excreted in the urine.     

Age-related decrease of urinary excretion of human epidermal growth factor (hEGF)

Epidermal growth factor (EGF) has been first isolated from the submandibular glands of the male mouse and recently from human urine. Despite its potent mitogenic effect in a variety of tissues, the physiological functions of EGF in human still remain undetermined. In order to study the effect of age on urinary human EGF (hEGF), we have evaluated urinary excretion of hEGF in normal subjects over a wide range of age (20–79 yr.) using homologous radioimmunoassay (RIA) for hEGF. Urinary excretion of hEGF expressed as a function of creatinine significantly decreased with increasing age, age, while females excreted significantly more hEGF than males. These data suggest that urinary excretion of hEGF decreases with age in normal subjects which may be due to reduced synthesis and/or secretion of hEGF.     

Dependence upon bile volume of the biliary excretion of bromocresol green and amaranth in the anaesthetized rat.

The kinetics of the biliary excretion of both bromocresol green and amaranth are better described in terms of rate equations that are functions of the cumulative volume of bile excreted rather than of time. The rate of disappearance of bromocresol green from the liver also appears to depend on the volume of bile excreted rather than on time. It is proposed that bromocresol green, and probably also amaranth, rapidly equilibrates between the hepatic and biliary compartments as a result of reabsorption from the biliary tree and that the rate-limiting factor in the biliary excretion of these dyes is the removal of dye from the biliary tree by bulk flow. Six methods for the graphical presentation of excretion data are examined and their use in the characterization of the kinetics of an excretion system is discussed.     

A high-salt meal produces natriuresis in humans without elevating plasma atriopeptin

The effects of a high-sodium meal on plasma atrial natriuretic peptide (atriopeptin) and renal sodium excretion were studied in eight normal human subjects. As expected, sodium excretion and urine osmolality increased following the meal. Plasma atriopeptin levels did not increase, however, after the high-sodium meal. In a control experiment, consumption of a low-sodium meal by six of the same subjects did not increase either urinary sodium excretion or plasma atriopeptin concentration. We conclude that the natriuresis elicited by a high-salt meal is not mediated by the atrial peptides.     

卵形鲳鲹幼鱼耗氧率和排氨率的初步研究

运用封闭流水式实验方法对不同体重和放养密度的卵形鲳鲹(Trachinoms ovatus)幼鱼耗氧率和排氨率进行了初步的研究。结果表明,卵形鲳鲹幼鱼的耗氧率随着鱼体重的增加而逐渐下降,排氨率总体上也呈降低的趋势,体重对卵形鲳鲹耗氧率、排氨率的影响均达到显著水平(P0.05);光照对卵形鲳鲹幼鱼的耗氧率和排氨率影响非常显著(P0.01),幼鱼在遮光条件下的耗氧率和排氨率分别比在自然光照条件下要低25.18%～40.76%和16.28%～40.28%;随着放养密度的增加,卵形鲳鲹幼鱼的耗氧率逐渐降低,排氨率随着密度的增加呈先上升后下降的趋势,放养密度对卵形鲳鲹耗氧率、排氨率的影响均达到显著水平(P0.05)。卵形鲳鲹的耗氧率和排氨率具有明显的昼夜变化,白天的耗氧率和排氨率均高于夜间值,耗氧率的低谷值为高峰值的69.68%,排氨率的低谷值为高峰值的30.91%。卵形鲳鲹幼鱼的窒息点溶解氧含量为(0.991±0.058)mg/L。     

Relationships among urinary kallikrein, mineralocorticoids and human hypertensive disease.

Urinary kallikrein excretion is reduced in patients with hypertension of unknown etiology. In addition, the excretion of this renal, kinin-forming enzyme was found to be elevated in hypertensive patients with primary aldosteronism. Aldosterone regulates kallikrein excretion, as normal subjects show increased kallikrein excretion in response to a low sodium intake, high potassium intake, or the synthetic mineralocorticoid, fludrocortisone, whereas kallikrein excretion falls during treatment with spironolactone. The relationship between kallikrein excretion and aldosterone activity may directly reflect the intrarenal activity of the kallikrein-kinin system, as determined by studies of kallikrein levels from isolated renal cells or of plasma kinin levels in man in response to postural changes or saline loads. Some patients with essential hypertension do not show a normal increase in kallikrein excretion in response to low dietary sodium intake despite an apparently normal aldosterone response, suggesting that there may be a defect in the renal kallikrein-kinin system in these patients. Whether these findings are of pathogenetic significance in human hypertensive disease remains to be determined.