The effect of relatively unimportant deviations in the normal blood volume on the urinary excretion of water and sodium chloride

2009 ◽  
Vol 130 (S207) ◽  
pp. 15-18
Keyword(s):  
Sodium Chloride ◽  
Urinary Excretion ◽  
Blood Volume ◽  
Normal Blood

Specific alterations in sodium chloride intake after hypothalamic lesions in the rat

1963 ◽  
Vol 205 (5) ◽  
pp. 922-926 ◽  
Author(s):  
Miguel R. Covian ◽  
José Antunes-Rodrigues
Keyword(s):  
Sodium Chloride ◽  
Urinary Excretion ◽  
The Other ◽  
Urinary Output ◽  
Water Ingestion ◽  
Hypothalamic Lesions ◽  
Paraventricular Nuclei ◽  
Electrolytic Lesions ◽  
Specific Increase ◽  
Sodium Chloride Intake

Bilateral electrolytic lesions in the hypothalamus of the rat elicited either a decrease or increase in 2% NaCl intake, without a significant change in water ingestion. Lesions placed in the anterior hypothalamus involving supraoptic or paraventricular nuclei, or both, resulted in a conspicuous fall (as much as 93%) of NaCl intake. The decreased consumption remained to the end of the experiments which in some rats lasted 105 days and was accompanied by a decrease in NaCl urinary output. On the contrary, lesions placed in the central hypothalamus determined a specific increase of NaCl intake together with an augmented urinary excretion. The increased ingestion was permanent and lasted to the end of the experiment, attaining in one rat the value of 290%. To account for these results two provisional explanations are advanced, one of them considering the possibility of the existence of two areas of opposite effects regarding NaCl ingestion and the other claiming a neurohumoral mechanism in which oxytocin and aldosterone could be the two responsible hormones.

Validation of highly specific and sensitive radioimmunoassays for lutropin, follitropin, and free alpha subunit in unextracted urine

1990 ◽  
Vol 36 (2) ◽  
pp. 340-344 ◽  
Author(s):  
H Landy ◽  
A L Schneyer ◽  
R W Whitcomb ◽  
W F Crowley
Keyword(s):  
Monoclonal Antibody ◽  
Urinary Excretion ◽  
Blood Volume ◽  
High Sensitivity ◽  
High Specificity ◽  
Urine Samples ◽  
Alpha Subunit ◽  
Glycoprotein Hormones ◽  
Urinary Ph ◽  
Freeze Thaw

Abstract Measurement of the urinary excretion of lutropin (LH) and follitropin (FSH) and their common free alpha subunit (FAS) assists in monitoring the maturation of the hypothalamic-pituitary-gonadal axis and in understanding the physiology of the pituitary glycoprotein hormones. Here we describe sensitive, specific polyclonal radioimmunoassays for LH and FSH and a monoclonal radioimmunoassay for FAS for use with urine--assays unperturbed by alterations in urinary pH or osmolarity within the broad physiological range encountered in urine. Concordance between LH, FSH, and FAS concentrations in extracted and unextracted urine samples was high. Linearity and parallelism with the standard curves was observed with addition of 25 to 200 microL of unextracted urine. No effect on glycoprotein concentration was seen after as many as 10 freeze-thaw cycles. The need for extraction was further obviated by the high sensitivity of each assay, reflected by minimum detectable doses well below the concentrations encountered in patients' samples. Thus we have measured gonadotropins in unextracted urine as precisely as in extracted urine. We also have demonstrated an equally versatile assay for urinary alpha subunit, using a monoclonal antibody of high specificity for this monomer in its free, uncombined form. These radioimmunoassays complement assays of gonadotropins and free alpha subunit in serum and will allow longitudinal investigations otherwise limited by the constraints of the patient's blood volume.

scholarly journals Blood Volume and Molybdenum Toxicity in Rabbits

Blood ◽  
1953 ◽  
Vol 8 (12) ◽  
pp. 1105-1106 ◽  
Author(s):  
JACK D. BURKE ◽  
L. R. ARRINGTON ◽  
G. K. DAVIS
Keyword(s):  
Body Weight ◽  
Blood Volume ◽  
Normal Blood ◽  
Normal Range

Abstract The blood volume of normal rabbits and rabbits anemic with molybdenum toxicity was determined using the dye and P32 methods. The blood volume per unit of body weight was found to be within the normal range indicating that rabbits were able to maintain normal blood volume even though anemic as a result of molybdenum toxicity.

scholarly journals Plasma endothelin and renal endothelin are two distinct systems involved in volume homeostasis

1995 ◽  
Vol 268 (5) ◽  
pp. H1829-H1837 ◽  
Author(s):  
G. G. Serneri ◽  
P. A. Modesti ◽  
I. Cecioni ◽  
D. Biagini ◽  
A. Migliorini ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Plasma Concentration ◽  
Urinary Excretion ◽  
Blood Volume ◽  
Volume Expansion ◽  
Venous Blood ◽  
Fold Increase ◽  
Volume Depletion ◽  
Local Formation ◽  
Young Subjects

This study of seven healthy young subjects was designed both to establish whether endothelin-1 (ET-1) is involved in the homeostasis of blood volume and to clarify the relationship between plasma and urinary ET-1. Acute volume expansion (+17%) caused increases in venous blood pressure (+4.4 mmHg) and the plasma concentration of ET-1 (+129%) and a decrease (-99%) in the urinary excretion of ET-1. Volume depletion (-8.5%) provoked an increase in the plasma concentration of ET-1 without altering the urinary excretion of ET-1. Passive elevation of an arm resulting in a local decrease of venous blood pressure (-17 mmHg) elicited an increase of the local formation of ET-1, with a 10-fold increase in the venous-arterial gradient compared with the opposite arm, which lay at the level of the heart. The increased local formation of ET-1 was blunted by volume expansion. The results indicate that 1) plasma ET-1 and urinary ET-1 represent two different endothelin-generating systems, both of which are involved in the regulation of blood volume, and 2) plasma ET-1 appears to be an important mechanism for the long-lasting adaptations of venous wall tension to changes in blood volume.

Regulation of atrial natriuretic factor release by endothelin in ovine fetuses

1994 ◽  
Vol 267 (2) ◽  
pp. R380-R386 ◽  
Author(s):  
C. Y. Cheung
Keyword(s):  
Urinary Excretion ◽  
Blood Volume ◽  
Atrial Natriuretic Factor ◽  
Direct Action ◽  
Venous Pressure ◽  
Recovery Period ◽  
Control Period ◽  
Natriuretic Factor ◽  
Potent Vasoconstrictor ◽  
Atrial Natriuretic

Endothelin is a potent vasoconstrictor synthesized by vascular endothelial cells. In the adult, endothelin has been shown to stimulate the release of atrial natriuretic factor (ANF) through a direct action on atrial cardiocytes. The present study was designed to investigate, in the fetus, whether endothelin would similarly release ANF into the circulation. In addition, the effects of endothelin on fetal cardiovascular and urinary functions were explored. Chronically catheterized ovine fetuses between 126 and 139 days gestation (term 147 days) were used for the study. After a 30-min control period, the fetuses were infused intravenously with vehicle (n = 6) or endothelin-1 (n = 9) at 25 ng.min-1.kg-1 for 30 min, and this was followed by a 60-min recovery period. In response to endothelin infusion, plasma ANF levels were significantly elevated. Endothelin infusion acutely increased fetal arterial pressure without affecting venous pressure. Fetal heart rate decreased, and blood volume was reduced. Fetal urine flow rate and urinary excretion of electrolytes did not change during the endothelin infusion but were elevated during the recovery period. The fetus developed hypoxia and acidemia. Thus our study demonstrates that endothelin is effective in stimulating ANF release in the fetus, and this effect appears to be unrelated to the venous pressure changes. In addition, the results suggest that endothelin is a potent vasoconstrictor of the fetal systemic and umbilical vascular beds. The decrease in blood volume and increase in urinary excretion of fluid and electrolytes in response to endothelin are consistent with the known actions of ANF, which is elevated during endothelin infusion.

scholarly journals Influence of gender on renal thiazide diuretic receptor density and response.

1994 ◽  
Vol 5 (4) ◽  
pp. 1112-1119
Author(s):  
Z Chen ◽  
D A Vaughn ◽  
D D Fanestil
Keyword(s):  
Regression Analysis ◽  
Sodium Chloride ◽  
Urinary Excretion ◽  
Thiazide Diuretic ◽  
Renal Excretion ◽  
Receptor Density ◽  
Sprague Dawley ◽  
Acid Base ◽  
Sprague Dawley Rats ◽  
Before And After

The influence of gender and gonadectomy on (1) the density of the renal thiazide-sensitive ion transporter, as quantitated by the ability of renal membranes to bind (3H)metolazone, and (2) the changes in the urinary excretion of electrolytes caused by maximal bendroflumethiazide (BFTZ) in Sprague-Dawley rats was determined. The density of the thiazide receptor was twofold higher (P < 0.001) in females than in males. Orchiectomy increased thiazide receptor significantly in one of two studies (P < 0.01). Ovariectomy decreased thiazide receptor by more than 20% (P < 0.01) in both studies. The rates of the urinary excretion of sodium and chloride after BFTZ and the increases in the urinary excretion of sodium, chloride, and ammonium caused by BFTZ were greater in intact females than in intact males; BFTZ decreased the urinary excretion of calcium 50% in intact females, but not in intact males. Regression analysis of the thiazide receptor (in intact and gonadectomized animals) versus the urinary excretion of electrolytes before and after BFTZ yielded a model in which one-third of the variation in thiazide receptor could be related to the change in the excretion of calcium and ammonium produced by BFTZ, raising the possibility that the density of the thiazide receptor might be related to calcium or acid-base homeostasis. It was concluded that the renal excretion of sodium, chloride, calcium, and ammonium are, in part, controlled by gender and sex hormones via their regulation of the renal density of the thiazide diuretic receptor.

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