Relationship between plasma osmolality and plasma vasopressin in human subjects

1980 ◽  
Vol 238 (4) ◽  
pp. E313-E317 ◽  
Author(s):  
M. Hammer ◽  
J. Ladefoged ◽  
K. Olgaard
Keyword(s):  
Linear Models ◽  
Human Subjects ◽  
Plasma Osmolality ◽  
Metabolic Clearance ◽  
Parabolic Model ◽  
Pronounced Increase ◽  
Plasma Vasopressin ◽  
Log Linear ◽  
The Relationship ◽  
Best Fit

The relationship between plasma osmolality (pOsm) and plasma vasopressin (pAVP) was studied in 13 human subjects during dehydration. The fit of linear, log-linear, parabolic, and exponential models was tested. For all of the data, the nonlinear models had the best fit. However, when individual differences in either gain or threshold were allowed for, the linear models were better than log-linear models. Finally, analyses were made with individual data points. Linear models had the best fit in half of the subjects, whereas for the others the parabolic model gave the best fit. For those subjects investigated in the low range of the osmoregulatory curve, a linear relationship was found, whereas, for those having the most pronounced increase in pOsm, the most significant improvement was found with the parabolic model. This finding indicates that the relationship is not stable during dehydration in the whole range and that hypovolemia probably can influence the secretion rate and/or metabolic clearance rate and thereby the relationship.

Regulation of plasma vasopressin by plasma osmolality and carotid sinus pressure in anesthetized rabbits

1994 ◽  
Vol 266 (3) ◽  
pp. R796-R801
Author(s):  
C. S. Scott ◽  
J. Sharp-Kehl ◽  
C. A. Redekopp ◽  
J. R. Ledsome
Keyword(s):  
Linear Regression ◽  
Aortic Arch ◽  
Carotid Sinus ◽  
Plasma Osmolality ◽  
Lower Plasma ◽  
Plasma Vasopressin ◽  
Baroreceptor Stimulation ◽  
The Relationship ◽  
Sinus Pressure

The purpose of the experiments was to investigate the effect of changes in carotid sinus baroreceptor stimulation on plasma vasopressin (AVP) at different plasma osmolalities in the anesthetized artificially ventilated rabbit. Both carotid sinuses were isolated and perfused with blood at servo-controlled pressures. The vagus and aortic depressor nerves were sectioned bilaterally to eliminate input from atrial and aortic arch baroreceptors. Saline (0.3%, wt/vol) was infused to lower plasma osmolality, and 5% saline was infused to raise plasma osmolality. At three plasma osmolalities, the carotid sinus pressure (CSP) was changed from 100 mmHg to 40 and 140 mmHg and returned to 100 mmHg. There were no changes in plasma AVP in response to changes in CSP at low plasma osmolality (289 mosmol/kgH2O), but at medium (309 mosmol/kgH2O) and high (323 mosmol/kgH2O) osmolality, plasma AVP was higher at 40 than at 140 mmHg CSP. The relationship between plasma AVP and plasma osmolality was expressed as a linear regression at each CSP. Changes in CSP changed the sensitivity but not the threshold of the osmotic control of AVP release.

scholarly journals Modelling Synergy using Manifest Categorical Variables

1998 ◽  
Vol 22 (3) ◽  
pp. 537-557 ◽  
Author(s):  
Alexander von Eye ◽  
Christof Schuster ◽  
William M. Rogers
Keyword(s):  
Social Sciences ◽  
Linear Models ◽  
Contraceptive Use ◽  
Natural Sciences ◽  
Alternative Methods ◽  
Categorical Variables ◽  
The Social ◽  
Log Linear ◽  
The Relationship

This paper discusses methods to model the concept of synergy at the level of manifest categorical variables. First, a classification of concepts of synergy is presented. A dditive and nonadditive concepts of synergy are distinguished. Most prominent among the nonadditive concepts is superadditive synergy. Examples are given from the natural sciences and the social sciences. M delling focuses on the relationship between the agents involved in a synergetic process. These relationships are expressed in form of contrasts, expressed in effect coding vectors in design matrices for nonstandard log-linear models. A method by Schuster is used to transform design matrices such that parameters reflect the proposed relationships. A n example reanalyses data presented by Bishop, Fienberg, and Holland (1975) that describe the development of thromboembolisms in women who differ in their patterns of contraceptive use and smoking. Alternative methods of analysis are com pared. Implications for developmental research are discussed.

scholarly journals The relationship between plasma osmolality and plasma vasopressin concentration is altered in old male Lewis rats

1994 ◽  
Vol 131 (1) ◽  
pp. 86-90 ◽  
Author(s):  
Dirk Terwel ◽  
Jellemer Jolles
Keyword(s):  
Kidney Function ◽  
Salt Solution ◽  
Plasma Osmolality ◽  
Linear Increase ◽  
Lewis Rats ◽  
Plasma Vasopressin ◽  
Age Related ◽  
Basal Plasma ◽  
Reduced Kidney Function ◽  
The Relationship

Terwel D, Jolles J. The relationship between plasma osmolality and plasma vasopressin concentration is altered in old male Lewis rats. Eur J Endocrinol 1994;131:86–90. ISSN 0804–4643 Kidney dysfunction has been observed in aged humans and rats, the primary cause of which may reside in the kidney itself or in the hypothalamus. The latter possibility is suggested by the increased release of AVP in response to salt infusion in humans. The effect of age on the relationship between plasma osmolality and plasma AVP concentration has never been verified in an animal model. Therefore, in the present study, 9% salt solution was infused into adult and aged Lewis rats, and plasma AVP concentration and osmolality were measured. Basal plasma AVP concentration, osmolality and total water intake were not altered in aged Lewis rats as compared with adult animals, indicating the absence of overt disturbances in water homeostasis. Infusion of 9% salt solution resulted in a linear increase in plasma osmolality in both adult and aged rats. Plasma osmolality increased more with time in aged animals than in adult animals, suggesting an age-related difference in kidney function during salt infusion. Plasma AVP concentration increased 50% less with osmolality at relatively low osmolalities, but not at relatively high osmolalities. The altered relationship between plasma osmolality and plasma AVP concentration in rats with age may be related to changes in neurons monitoring osmolality or to changes in baroreflex regulation. The data suggest that reduced kidney function with age does not result from an altered relationship between plasma osmolality and plasma AVP concentration. D Terwel, University of Limburg, Department of Neuropsychology and Psychobiology, PO Box 616, 6200 MD Maastricht, The Netherlands

scholarly journals Analysis of Traffic Accidents Caused by Drivers by Using Log-Linear Models

1970 ◽  
Vol 24 (6) ◽  
pp. 495-504 ◽  
Author(s):  
Hülya Olmuş ◽  
Semra Erbaş
Keyword(s):  
Odds Ratio ◽  
Relative Frequency ◽  
Traffic Accidents ◽  
Linear Models ◽  
Linear Modelling ◽  
Accident Severity ◽  
Modelling Effort ◽  
Log Linear ◽  
Best Fit ◽  
Multiple Interactions

Log-linear modelling is advanced as a procedure to identify factors that underlie the relative frequency of occurrence of various characteristics. The purpose of this study is to present a modelling effort using log-linear models to estimate the relationships between driver’s fault and carelessness and the traffic variables such as gender, accident severity, and accident time. The study was conducted in four different districts in Ankara, the capital of Turkey. There were 1,325 people selected for the study; and they were asked whether they had been in an accident. Four hundred and forty-eight of them answered that they had been involved in an accident. As drivers, 276 out of 448 people, namely 61.6%, had traffic accidents. The data on the variables, namely gender, driver’s fault and carelessness, accident severity and accident time, were collected through a questionnaire survey. Detailed information has been created based on this information. The analysis showed that the best-fit model regarding these variables was the log-linear model. Furthermore, the odds ratio between these variables, the associations of the factors with the accident severity and the contributions of various factors, and the multiple interactions between these variables were assessed. The obtained results provide valuable information in regard to preventing undesired consequences of traffic accidents.

Osmoregulation of thirst and vasopressin secretion in human subjects: effect of various solutes

1983 ◽  
Vol 244 (6) ◽  
pp. E607-E614 ◽  
Author(s):  
R. L. Zerbe ◽  
G. L. Robertson
Keyword(s):  
Hypertonic Saline ◽  
Human Subjects ◽  
Plasma Osmolality ◽  
Detectable Effect ◽  
Healthy Human ◽  
Hypertonic Glucose ◽  
Plasma Vasopressin ◽  
Human Volunteers ◽  
Vasopressin Secretion ◽  
High Degree

Various hypertonic solutions were infused in healthy human volunteers to determine their effect on thirst and vasopressin secretion. Hypertonic saline and mannitol produced prompt and parallel increases in plasma osmolality and vasopressin concentration. For both of these solutes, there was a high degree of correlation between these measurements. The slope describing this relationship varied considerably between individuals, but the same subjects showed similar slopes with either saline or mannitol. Both solutions stimulated thirst. Hypertonic urea infusions produced a comparable rise in osmolality but produced a smaller increase in plasma vasopressin and stimulated thirst in only one of the subjects. With urea, the correlation between plasma osmolality and vasopressin was significantly lower. Within individuals, the slope describing this relationship was significantly correlated with that seen during hypertonic saline. Hypertonic glucose significantly increased plasma osmolality but decreased plasma vasopressin and had no detectable effect on thirst. We conclude that osmoregulation of vasopressin in humans is mediated by a selective osmoreceptor that is located primarily outside of the blood-brain barrier and that individual differences in osmoregulatory sensitivity are not solute specific.

Cardiac receptor influences on the plasma osmolality-plasma vasopressin relationship

1984 ◽  
Vol 246 (3) ◽  
pp. H360-H368 ◽  
Author(s):  
B. C. Wang ◽  
W. D. Sundet ◽  
M. O. Hakumaki ◽  
P. G. Geer ◽  
K. L. Goetz
Keyword(s):  
Volume Expansion ◽  
Regression Line ◽  
Plasma Osmolality ◽  
Specific Effect ◽  
Volume Changes ◽  
Volume Depletion ◽  
Plasma Vasopressin ◽  
Plasma Arginine ◽  
The Relationship ◽  
Cardiac Receptors

Changes in blood volume are capable of altering the relationship between plasma osmolality (Posmol) and plasma arginine vasopressin (PAVP), presumably via a reflex elicited from cardiovascular receptors, but the precise location of the receptors involved in this response has not been established. Because cardiac receptors are capable of influencing AVP secretion, their specific effect was examined by producing volume changes in cardiac-denervated (CD) dogs and comparing the Posmol-PAVP relationship in these dogs with data from comparable experiments on sham-operated control dogs (cardiac-sham, CS). Posmol was increased by water deprivation for 96 h (volume depletion) and also by administration of hypertonic saline for 2 h (volume expansion). The slope of the regression line describing the Posmol-PAVP relationship in CS control dogs was steeper (P less than 0.01) during volume depletion (0.390) than it was during volume expansion (0.228), thus suggesting that volume depletion had enhanced and volume expansion had inhibited the secretion of AVP. In contrast, the slope of the regression line delineating the Posmol-PAVP relationship in CD dogs was essentially the same during volume depletion (0.288) as it was during volume expansion (0.291). It would seem that most, if not all, of the volume influences on the Posmol-PAVP relationship are mediated via reflex effects elicited by cardiac receptors.

Role of vasopressin in fetal homeostasis

1982 ◽  
Vol 242 (6) ◽  
pp. F740-F744
Author(s):  
S. S. Daniel ◽  
R. I. Stark ◽  
M. K. Husain ◽  
L. V. Baxi ◽  
L. S. James
Keyword(s):  
Urine Output ◽  
Plasma Osmolality ◽  
Urine Osmolality ◽  
Maternal Plasma ◽  
Third Trimester ◽  
The Third ◽  
Plasma Vasopressin ◽  
The Relationship ◽  
Linear Correlations

The role of vasopressin (VP) and the kidney in the maintenance of solute and volume homeostasis was studied in chronically instrumented fetal lambs during the third trimester. Plasma VP, urine and plasma osmolality, and urine output were measured in 74 simultaneous samples. The results show a strong positive nonlinear correlation between plasma VP and osmolality when a latter is higher than 290 mosmol/kg (r = 0.803, P = 0.03) and between plasma VP and urine osmolality (r = 0.806, P = 0.05). No correlation was found between fetal and maternal plasma VP. However, linear correlations were found in plasma osmolality and sodium concentrations between mother and fetus; mean maternal-fetal gradients were 4 mosmol/kg and 3.1 meq/liter, respectively. The highest values for plasma VP and osmolality found in our study were 7.0 pg/ml and 317 mosmol/kg, respectively. There values corresponded to urine output of 0.02 ml.kg-1.min-1 and osmolality of 517 mosmol/kg. In conclusion, there studies demonstrate that the relationship among plasma osmolality, plasma vasopressin concentration, and urine osmolality in the lamb fetus are qualitatively similar to those of the adult. The results suggest that the fetal neurohypophysis and kidney may participate in the maintenance of fetal osmolar and volume homeostasis.

6. Some Log-Linear and Log-Nonlinear Models for Ordinal Scales with Midpoints, with an Application to Public Opinion Data

1998 ◽  
Vol 28 (1) ◽  
pp. 263-292 ◽  
Author(s):  
Michael E. Sobel
Keyword(s):  
Public Opinion ◽  
Linear Models ◽  
Nonlinear Models ◽  
Empirical Work ◽  
Stochastic Ordering ◽  
Response Scale ◽  
Ordinal Response ◽  
Response Scales ◽  
Log Linear ◽  
The Relationship

Ordinal response scales with a middle category are widely used in public opinion studies, psychology, medicine, computed tomography and other fields. The usual models in the statistical literature for ordinal response variables treat the case where the scale has a natural middle category no differently from the case where the scale does not have a middle category. This paper proposes new models for the analysis of ordinal response scales with middle categories, applying these to data collected in 1993–1994 on American opinion toward the balance between environmental quality and economic prosperity. Some of the models should also be useful when the scale does not have a natural middle category. The models are easily used to address issues of concern in empirical work—for example, stochastic ordering among covariate classes and asymmetry about the middle category. Log-linear models are considered in Section 2. The relationship between the normal distribution and a quadratic log-linear model with known scores, discussed in this section, is the basis for Section 3, which considers a log-nonlinear model with unknown scores estimated from the data. Section 4 shows how generalized log-linear and generalized log-nonlinear models can be used to simultaneously study whether the response is below, at, or above the midpoint, and the conditional distribution of responses above (below) the midpoint. These models are also useful when the response scale is viewed as nested and/or the response process is sequential.

Plasma AVP and renal concentrating defect in chloride depletion metabolic alkalosis

1988 ◽  
Vol 254 (1) ◽  
pp. F15-F24 ◽  
Author(s):  
L. N. Peterson ◽  
D. Sztorc ◽  
A. Jamshaid ◽  
J. Kucharczyk ◽  
D. Bichet ◽  
...  
Keyword(s):  
Metabolic Alkalosis ◽  
Linear Models ◽  
Plasma Osmolality ◽  
High Water ◽  
Water Turnover ◽  
Chloride Depletion ◽  
Increased Sensitivity ◽  
Plasma Arginine ◽  
Log Linear ◽  
Concentrating Defect

These studies were undertaken to determine the effect of chronic chloride depletion metabolic alkalosis (Cl-DEP-MALK) on water intake, plasma arginine vasopressin (AVP) levels, and renal concentrating ability. Cl-DEP-MALK was induced by feeding a chloride-free diet to rats subjected to gastric drainage and to dogs treated with furosemide. All of the animals developed a urine concentrating defect, polydipsia, and a persistent reduction in plasma osmolality. However, AVP release was not suppressed. The results of osmotic loading experiments in dogs analyzed using either linear or log-linear models have shown that chronic Cl-DEP-MALK significantly alters the relation between plasma osmolality and plasma AVP. In the classic linear analysis the results suggest that Cl-DEP-MALK reduces the plasma osmolality at which plasma AVP can be detected, i.e., reduced “threshold,” and increases the slope of the plasma osmolality-to-plasma AVP relation nearly twofold, i.e., increased “sensitivity.” Finally, we provide evidence that the concentrating defect is not related to high water turnover or deficient endogenous AVP and is therefore nephrogenic.

scholarly journals Comparing Log-Linear and Best-Fit Models to Evaluate the Long-Term Persistence of Enteric Markers in Sewage Spiked River Water

2021 ◽  
Vol 3 ◽  
Author(s):  
Yolanda M. Brooks ◽  
Joan B. Rose
Keyword(s):  
Water Quality ◽  
River Water ◽  
Linear Models ◽  
Decay Rates ◽  
Fecal Indicator ◽  
Quality Models ◽  
Linear Pattern ◽  
Log Linear ◽  
Water Quality Models ◽  
Best Fit

Water quality models use log-linear decay to estimate the inactivation of fecal indicator bacteria (FIB). The decay of molecular measurements of FIB does not follow a log-linear pattern. This study examined the factors associated with the persistence of Escherichia coli uidA, enterococci 23S rDNA, and Bacteroides thetataiotaomicron 1,6 alpha mannanase in microcosms containing 10% (vol/vol) sewage spiked river water stored at 4°C for up to 337 days. The study estimated the markers' persistence with log-linear models (LLMs) to the best-fit models, biphasic exponential decay (BI3) and log-logistic (JM2) and compared the estimates from the models. Concentrations of B. thetataiotaomicon decreased to levels below detection after 31 days in storage and were not fit to models. BI3 and JM2 were fit to E. coli and enterococci, respectively. LLMs had larger Bayesian information criterion values than best-fit models, indicating poor fit. LLMs over-estimated the time required for 90% reduction of the indicators (T90) and did not consider dynamic rates of decay. Time in storage and indicator species were associated with the persistence of the markers (p < 0.001). Using the T90 values of the best-fit models, enterococci was the most persistent indicator. Our data supports the use of best fit models with dynamic decay rates in water quality models to evaluate the decay of enteric markers.

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