Measurement of Concentrations of Angiotensin I in Human Blood by Radioimmunoassay

1973 ◽  
Vol 45 (1) ◽  
pp. 51-64 ◽  
Author(s):  
M. A. Waite

1. A radioimmunoassay for angiotensin I is described. 2. An extraction procedure for angiotensin I from blood was developed, using alcoholic precipitation to stop the renin/renin substrate reaction. 3. The normal range found for angiotensin I in venous blood was 11–88 pg/ml and in arterial blood 12–72 pg/ml. 4. Angiotensin I levels fell following bilateral nephrectomy but angiotensin I was still detected several weeks following operation.

1975 ◽  
Vol 228 (2) ◽  
pp. 369-375 ◽  
Author(s):  
JS Carvalho ◽  
R Shapiro ◽  
P Hopper ◽  
LB Page

Micromethods for measurement of plasma renin concentration (PRC) and plasma renin-substrate concentration (PSC) have been developed for rat plasma with radioimmunoassay of angiotensin I. An improved technique for aortic implantation of plastic cannulas was developed for use in experiments 1-2 wk in duration. The effects on components of renin system of anesthesia and tail cutting were studied. Arterial blood was sampled through cannulas without animal manipulation. PRC varied little in unanesthetized rats, was moderately and variably increased during pentobarbital anesthesia, and was markedly and consistently elevated during ether anesthesia. PSC was unchanged during anesthesia. PRC was increased in blood obtained by tail cutting within 1-2 min after cutting. With the use of the methods and techniques described here serial studies of the renin system in plasma of unanesthetized rats are shown to be feasible. A role for the sympathetic nervous system in the mediation of renin secretion by ether is proposed.


1994 ◽  
Vol 266 (1) ◽  
pp. H17-H20 ◽  
Author(s):  
D. F. Anderson ◽  
A. Barbera ◽  
J. J. Faber

The role of the kidneys in the maintenance of arterial blood pressure was examined in fetal sheep. Surgery was performed on 11 pregnant sheep (8 twin pregnancies) at approximately 125 days. All 19 fetuses were instrumented with hindlimb arterial and venous catheters. Eleven of the fetuses (but only 1 of each twin) were also bilaterally nephrectomized. Fetal arterial blood pressure was measured several times between 2 and 14 days after surgery. Arterial blood pressure in the intact fetuses increased from 44 +/- 1 to 47 +/- 1 mmHg (SE) but gradually decreased from 37 +/- 4 to 25 +/- 3 mmHg in the nephrectomized group. Whereas the arterial blood pressures measured on the first day of the experiment were not statistically significantly different between the two groups, by the final day of the experiment the arterial blood pressure of the intact fetuses was much higher than that of the nephrectomized fetuses. Venous blood pressure was similar in the two groups. We conclude that bilateral nephrectomy in fetal sheep not only stops the normal gestational increase in arterial blood pressure but also leads to a progressive decline.


1994 ◽  
Vol 267 (6) ◽  
pp. R1522-R1527 ◽  
Author(s):  
J. J. Faber ◽  
D. F. Anderson

Nine bilaterally nephrectomized fetal sheep were infused for 6 days with angiotensin I in sterile water, and five nephrectomized fetal sheep were infused for 6 days with water alone. Total dose of angiotensin was 13.8 +/- 8.6 (SD) mg/kg fetal dry wt, and the total volumes of infused water were 303 +/- 201 and 423 +/- 164 ml, respectively. Of the fetuses infused with angiotensin I, one was of normal appearance, two showed moderate hydrops fetalis, and the remaining fetuses were grossly hydropic. All water-infused fetuses were normal. Their wet-to-dry weight ratios were 7.98 and 6.36 (P < 0.015), representing a 25% of normal body weight excess of water in the angiotensin I-infused fetuses. Six days of angiotensin I infusion caused a gradual rise in fetal arterial blood pressure from 37 +/- 15 to 81 +/- 15 mmHg (P < 0.05) and a gradual rise in venous blood pressure from 2.7 +/- 1.0 to 10.5 +/- 1.7 mmHg (P < 0.05). It was concluded that the fetal edema was due to the elevation in venous pressure. Plasma concentrations of Na+, K+, Cl-, HCO3-, total alpha-amino acids, fructose, glucose, and lactate in the fetus and the ewe did not identify an osmotically active solute responsible for the transplacental attraction of excess water into the conceptus, and the mechanism that attracted this excess water across the placenta remains unclear.


1982 ◽  
Vol 242 (1) ◽  
pp. F38-F45
Author(s):  
A. J. Lonigro ◽  
D. W. Brash ◽  
A. H. Stephenson ◽  
L. J. Heitmann ◽  
R. S. Sprague

In anesthetized laparotomized male mongrel dogs with ventilatory rate set at 10 breath.min-1, tidal volume was adjusted so that control arterial pH and PCO2 were within the normal range for unanesthetized dogs. Control renal venous PGE2 and PGF2 alpha concentrations were comparable to those of unanesthetized dogs, namely, 57 +/- 10 and 114 +/- 18 pg.ml-1, respectively. In contrast, control arterial plasma renin activity (PRA), 6.6 +/- 1.2 ng.ml-1.h-1, was considerably greater than in unanesthetized dogs. Stepwise increases in ventilatory rate increased renal venous PGE2 and PGF2 alpha to 109 +/- 18 and 205 +/- 41 pg.ml-1, respectively. Hyperventilation reduced PCO2 and increased pH and PRA but had no effect on renal blood flow, arterial blood pressure, or arterial PGE2 and PGF2 alpha concentrations. When the ventilatory rate was returned to control levels, pH, PCO2, PRA, and renal venous PGE2 and PGF2 alpha concentrations returned to control. Ventilatory rate or some consequence of altering ventilatory rate is, therefore, a determinant of renal venous efflux of PGE2 and PGF2 alpha. Moreover, it may be a more important determinant of "resting" concentrations of prostaglandins in renal venous blood than anesthesia, laparotomy, or PRA.


1966 ◽  
Vol 16 (01/02) ◽  
pp. 032-037 ◽  
Author(s):  
D Ogston ◽  
C. M Ogston ◽  
N. B Bennett

Summary1. The concentration of the major components of the fibrinolytic enzyme system was compared in venous and arterial blood samples from male subjects.2. The plasminogen activator concentration was higher in venous blood and the arterio-venous difference increased as its concentration rose, but the ratio of the arterial to venous level remained constant.3. No arterio-venous difference was found for anti-urokinase activity, antiplasmin, plasminogen and fibrinogen.4. It is concluded that venous blood determinations of the components of the fibrinolytic enzyme system reflect satisfactorily arterial blood levels.


Author(s):  
A. G. Belova ◽  
E. V. Zimina ◽  
N. P. Simbirtsev

During a pathoanatomic autopsy, it is very important to correctly assess the color change of the organs. However, it is not always clear because the color depends on the spectrum of the incident light. There is also a subjective assessment of color. In addition, in animals with large amounts of circulating blood, for example, dogs, early imbibition occurs, which makes it difficult to assess the color of the organ and pathoanatomical diagnosis. We have proposed a simple and visual method of recognition of two pathological processes – inflammation and edema using colored filters. This technique also allows to accurately differentiate inflammation from postmortem imbibition, to recognize fibrin and hemorrhage well. Postmortem examination of different types of animals (predacious families of mustelids, canids, felids) was performed in accordance with Shore’s method in the prosectorium of the Pathonomy Department, K.I. Skryabin Moscow State Academy of Veterinary Medicine and Biotechnology visual analysis – under various artificial lights (fluorescent lamps with banded spectrum and halogen lamps). In the red filter are well identified the pathological processes associated with the venous blood presence in the tissues (venous hyperemia and pulmonary edema). The focus of venous hyperemia or edema in the red filter looks like a dark zone, and tissues, where arterial bloods predominated, aren’t detected in red filter. In the yellow – green filter the inflammation is clearly detected: the zone is brightly red and surrounding tissues become dark. Red colour filters have rather narrow band of transmittance from 600 to 700 nm. Yellow-green have a width zone – from 500 to 700 nm, including both red, and yellow-green part of spectrum. Oxidized hemoglobin in red part of spectrum absorbs ten time weaker, has more high reflectivity and looks red. Surrounding tissues reflect the red rays, which incident on them also red. Therefore, the zone of edema, venous hyperemia and hemorrhaging, containing venous blood, are detected the dark spot, and inflammation zone merges with the red background. Oxidized hemoglobin in the red spectrum part absorbs ten time weaker than reduced hemoglobin, has high reflectivity of the red spectrum part and looks brightly red, surrounding tissues reflect yellow-green spectrum part and look green. Therefore, the zones of inflammation, active hyperemia and hemorrhaging, containing arterial blood, sharp contrast with green background and are clearly visible. Diagnoses made with the help of color filters are confirmed by histological studies.


2019 ◽  
pp. 203-206
Author(s):  
Mevlut Demir ◽  
◽  
Muslum Sahin ◽  
Ahmet Korkmaz ◽  
◽  
...  

Carbon monoxide intoxication occurs usually via inhalation of carbon monoxide that is emitted as a result of a fire, furnace, space heater, generator, motor vehicle. A 37-year-old male patient was admitted to the emergency department at about 5:00 a.m., with complaints of nausea, vomiting and headache. He was accompanied by his wife and children. His venous blood gas measures were: pH was 7.29, partial pressure of carbon dioxide (pCO2) was 42 mmHg, partial pressure of oxygen (pO2) was 28 mmHg, carboxyhemoglobin (COHb) was 12.7% (reference interval: 0.5%-2.5%) and oxygen saturation was 52.4%. Electrocardiogram (ECG) examination showed that the patient was not in sinus rhythm but had atrial fibrillation. After three hours the laboratory examination was repeated: Troponin was 1.2 pg/ml and in the arterial blood gas COHb was 3%. The examination of the findings on the monitor showed that the sinus rhythm was re-established. The repeated ECG examination confirmed the conversion to the sinus rhythm. He was monitored with the normobaric oxygen administration.


Author(s):  
Magda Wiśniewska ◽  
Natalia Serwin ◽  
Violetta Dziedziejko ◽  
Małgorzata Marchelek-Myśliwiec ◽  
Barbara Dołęgowska ◽  
...  

Background/Aims: Renalase is an enzyme with monoamine oxidase activity that metabolizes catecholamines; therefore, it has a significant influence on arterial blood pressure regulation and the development of cardiovascular diseases. Renalase is mainly produced in the kidneys. Nephrectomy and hemodialysis (HD) may alter the production and metabolism of renalase. The aim of this study was to examine the effect of bilateral nephrectomy on renalase levels in the serum and erythrocytes of hemodialysis patients. Methods: This study included 27 hemodialysis patients post-bilateral nephrectomy, 46 hemodialysis patients without nephrectomy but with chronic kidney disease and anuria and 30 healthy subjects with normal kidney function. Renalase levels in the serum and erythrocytes were measured using an ELISA kit. Results: Serum concentrations of renalase were significantly higher in post-bilateral nephrectomy patients when compared with those of control subjects (101.1 ± 65.5 vs. 19.6 ± 5.0; p < 0.01). Additionally, renalase concentrations, calculated per gram of hemoglobin, were significantly higher in patients after bilateral nephrectomy in comparison with those of healthy subjects (994.9 ± 345.5 vs. 697.6 ± 273.4, p = 0.015). There were no statistically significant differences in plasma concentrations of noradrenaline or adrenaline. In contrast, the concentration of dopamine was significantly lower in post-nephrectomy patients when compared with those of healthy subjects (116.8 ± 147.7 vs. 440.9 ± 343.2, p < 0.01). Conclusions: Increased serum levels of renalase in post-bilateral nephrectomy hemodialysis patients are likely related to production in extra-renal organs as a result of changes in the cardiovascular system and hypertension.


Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3827
Author(s):  
Gemma Urbanos ◽  
Alberto Martín ◽  
Guillermo Vázquez ◽  
Marta Villanueva ◽  
Manuel Villa ◽  
...  

Hyperspectral imaging techniques (HSI) do not require contact with patients and are non-ionizing as well as non-invasive. As a consequence, they have been extensively applied in the medical field. HSI is being combined with machine learning (ML) processes to obtain models to assist in diagnosis. In particular, the combination of these techniques has proven to be a reliable aid in the differentiation of healthy and tumor tissue during brain tumor surgery. ML algorithms such as support vector machine (SVM), random forest (RF) and convolutional neural networks (CNN) are used to make predictions and provide in-vivo visualizations that may assist neurosurgeons in being more precise, hence reducing damages to healthy tissue. In this work, thirteen in-vivo hyperspectral images from twelve different patients with high-grade gliomas (grade III and IV) have been selected to train SVM, RF and CNN classifiers. Five different classes have been defined during the experiments: healthy tissue, tumor, venous blood vessel, arterial blood vessel and dura mater. Overall accuracy (OACC) results vary from 60% to 95% depending on the training conditions. Finally, as far as the contribution of each band to the OACC is concerned, the results obtained in this work are 3.81 times greater than those reported in the literature.


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