Prognostic value of initial arterial lactate level and lactate metabolic clearance rate in patients with acute paraquat poisoning

The accuracy of tracer methods for estimating free fatty acid (FFA) rate of appearance (Ra), either under steady-state conditions or under non-steady-state conditions, has not been previously investigated. In the present study, endogenous lipolysis (traced with 14C palmitate) was suppressed in six mongrel dogs with a high-carbohydrate meal 10 h before the experiment, together with infusions of glucose, propranolol, and nicotinic acid during the experimental period. Both steady-state and non-steady-state equations were used to determine oleate Ra ([3H]oleate) before, during, and after a stepwise infusion of an oleic acid emulsion. Palmitate Ra did not change during the experiment. Steady-state equations gave the best estimates of oleate inflow approximately 93% of the known oleate infusion rate overall, while errors in tracer estimates of inflow were obtained when non-steady-state equations were used. The metabolic clearance rate of oleate was inversely related to plasma concentration (P less than 0.01). In conclusion, accurate estimates of FFA inflow were obtained when steady-state equations were used, even under conditions of abrupt and recent changes in Ra. Non-steady-state equations, in contrast, may provide erroneous estimates of inflow. The decrease in metabolic clearance rate during exogenous infusion of oleate suggests that FFA transport may follow second-order kinetics.

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Glucagon and insulin metabolism in a portal-hypertensive rat model

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1987.253.2.g110 ◽

1987 ◽

Vol 253 (2) ◽

pp. G110-G115 ◽

Cited By ~ 1

Author(s):

E. Sikuler ◽

J. Polio ◽

R. J. Groszmann ◽

R. Hendler

Keyword(s):

Portal Vein ◽

Rat Model ◽

Clearance Rate ◽

Portal Blood Flow ◽

Portal System ◽

Metabolic Clearance ◽

Metabolic Clearance Rate ◽

Insulin Metabolism ◽

Portosystemic Shunting ◽

Glucagon And Insulin

The role that portosystemic shunting plays in inducing the alterations of glucagon and insulin metabolism, which are observed in chronic liver disease, was studied in a rat model of prehepatic portal hypertension induced by portal vein constriction. Net splanchnic output of the hormones into the portal circulation was calculated from the difference between portal and systemic concentrations multiplied by portal plasma flow. Metabolic clearance rate was calculated as the ratio between output and systemic concentration. Portal blood flow was measured by the radioactive microsphere technique. Glucagon output in the portal vein-ligated rats was higher than in the sham-operated controls (5.9 +/- 1.5 vs. 2.0 +/- 0.2 ng/min, P less than 0.05). The metabolic clearance rate of glucagon was not significantly different between the two groups. Insulin output was not significantly different between the two groups; however, the metabolic clearance rate of insulin in the portal vein-ligated rats was reduced in comparison with the sham-operated group (9.5 +/- 1.5 vs. 18.4 +/- 3.3 ml/min, P less than 0.05). Our results indicate that portosystemic shunting per se is sufficient to cause an increased splanchnic output of glucagon into the portal system and a decreased metabolic clearance of insulin.

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Production rate, metabolic clearance rate and blood concentration of progesterone in conscious and anaesthetized pregnant rats

Journal of Endocrinology ◽

10.1677/joe.0.1020357 ◽

1984 ◽

Vol 102 (3) ◽

pp. 357-363 ◽

Cited By ~ 6

Author(s):

B. J. Waddell ◽

N. W. Bruce

Keyword(s):

Production Rate ◽

Clearance Rate ◽

Blood Concentration ◽

Constant Infusion ◽

Metabolic Clearance ◽

Metabolic Clearance Rate ◽

Short Term ◽

Pregnant Rats ◽

Pregnant Rat ◽

Anaesthetized Rats

ABSTRACT Both production rate and metabolic clearance rate (MCR) of progesterone may vary rapidly and so effect short-term changes in blood concentration of the hormone. Here, a constant infusion and sampling technique was used to estimate these three characteristics of progesterone metabolism in seven conscious and ten anaesthetized rats on day 16 of pregnancy. After steady state was achieved, four samples were collected during a 1-h period from each rat. Mean values for production rate and MCR of progesterone in conscious rats were 14·0 ±1·4 μmol/day and 63·2 ± 6·2 litres/day respectively. Both values were substantially reduced in anaesthetized rats (8.6 ±0·8 μmol/ day and 39·4± 3·4 litres/day respectively) and so blood concentration was unchanged. The production rate was positively related to the total mass of luteal tissue (common correlation coefficient, r = 0·61, P <0·05). There were no consistent changes in the three characteristics with time but variation within rats was high. The estimated coefficients of variation for production rate, MCR and blood concentration within rats were 26, 18 and 17% in conscious and 27, 20 and 23% in anaesthetized rats respectively. Short-term changes in production rate and MCR generally were in the same direction (P <0·05). This reduced variation in blood concentration which would otherwise have occurred if production rate and MCR were unrelated. The pregnant rat is clearly capable of rapid shifts in production rate, MCR and blood concentration of progesterone and the positive relationship between production rate and MCR has a homeostatic effect on blood concentration. J. Endocr. (1984) 102, 357–363

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The Metabolic Clearance Rate of Progesterone in the Pregnant Rhesus Monkey*

Endocrinology ◽

10.1210/endo-95-5-1287 ◽

1974 ◽

Vol 95 (5) ◽

pp. 1287-1292 ◽

Cited By ~ 7

Author(s):

S.A. SHOLL AND ◽

R.C. WOLF

Keyword(s):

Rhesus Monkey ◽

Clearance Rate ◽

Metabolic Clearance ◽

Metabolic Clearance Rate

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Long-term mild jogging increases insulin action despite no influence on body mass index or VO2 max

Journal of Applied Physiology ◽

10.1152/jappl.1989.66.5.2206 ◽

1989 ◽

Vol 66 (5) ◽

pp. 2206-2210 ◽

Cited By ~ 66

Author(s):

Y. Oshida ◽

K. Yamanouchi ◽

S. Hayamizu ◽

Y. Sato

Keyword(s):

Body Mass Index ◽

Body Mass ◽

Clearance Rate ◽

Insulin Action ◽

Metabolic Clearance ◽

Metabolic Clearance Rate ◽

Before And After ◽

Plasma Insulin Levels ◽

Improve Glucose Tolerance

Physical training has been shown to improve glucose tolerance and insulin sensitivity. In the present study, insulin action was determined using the euglycemic clamp technique in six untrained nonobese subjects before, during, and after long-term mild regular jogging. After 1 yr of jogging, steady-state plasma insulin levels (I) decreased significantly, and the metabolic clearance rate of insulin was increased by 87%, although insulin infusion rate during the clamp was constant for each individual. The amount of glucose infused (glucose metabolism, M) tended to increase from 6.16 +/- 0.94 to 8.15 +/- 1.94 mg.kg-1.min-1 after regular jogging for 1 yr, although that was not statistically significant. However, M/I increases significantly from 0.060 +/- 0.012 to 0.184 +/- 0.056 (P less than 0.05) after 1 yr. The concentrations of plasma free fatty acids during the hyperinsulinemic clamp decreased more significantly after 1 yr of jogging (P less than 0.05). The concentrations of plasma glycerol decreased gradually before and after long-term regular jogging, showing only a 50–60% reduction in 120 min. Therefore, long-term mild regular jogging, which did not influence either body mass index or maximal O2 uptake, appears to improve insulin action in both carbohydrate and lipid metabolism and to increase the metabolic clearance rate of insulin.

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ADRENAL FUNCTION IN BREAST CANCER: PRODUCTION AND METABOLIC CLEARANCE RATE OF CORTISOL IN PATIENTS WITH EARLY OR ADVANCED BREAST CANCER AND IN NORMAL WOMEN *

Journal of Endocrinology ◽

10.1677/joe.0.0420425 ◽

1968 ◽

Vol 42 (3) ◽

pp. 425-432 ◽

Cited By ~ 19

Author(s):

V. JENSEN ◽

N. DESHPANDE ◽

R. D. BULBROOK ◽

T. W. DOOUSS

Keyword(s):

Breast Cancer ◽

Advanced Breast Cancer ◽

Cancer Patients ◽

Production Rate ◽

Clearance Rate ◽

Advanced Breast ◽

Metabolic Clearance ◽

Breast Cancer Patients ◽

Metabolic Clearance Rate ◽

Significant Difference

SUMMARY The production rate of cortisol in patients with early or advanced breast cancer was compared with that of controls of comparable age. The miscible pool of this hormone was raised in advanced breast-cancer patients due to a higher production rate. The plasma clearance of cortisol remained unaffected, resulting in a higher titre of cortisol (both total and unbound) in advanced breast-cancer patients. There was no significant difference in the production rate between the early breast-cancer cases and controls. The binding of cortisol to transcortin was studied in all cases. The amount of unbound cortisol was raised in advanced breast-cancer cases. There was a significant correlation between both total and unbound cortisol and the production rate of this hormone. The latter correlation suggests that there is no abnormality in the hepatic extraction of cortisol in these patients. The metabolic clearance rate was found to be of the order of the blood flow through the liver when unbound cortisol was used for its estimation, showing that it is the unbound cortisol which is removed by the liver.

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Publisher Correction: Hyperpolarized [1-13C]-acetate Renal Metabolic Clearance Rate Mapping

Scientific Reports ◽

10.1038/s41598-018-29057-7 ◽

2018 ◽

Vol 8 (1) ◽

Author(s):

Emmeli F. R. Mikkelsen ◽

Christian Østergaard Mariager ◽

Thomas Nørlinger ◽

Haiyun Qi ◽

Rolf F. Schulte ◽

...

Keyword(s):

Clearance Rate ◽

Metabolic Clearance ◽

Metabolic Clearance Rate

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