Influence of Low Level Handling Stress on Nitrogen Excretion of Bluegill Sunfish (Lepomis machrochirus Rafinesque)

1973 ◽  
Vol 102 (3) ◽  
pp. 629-630 ◽  
Author(s):  
J. Savitz
Keyword(s):  
Nitrogen Excretion ◽  
Bluegill Sunfish ◽  
Handling Stress ◽  
Low Level

Nitrogen Excretion and Protein Consumption of the Bluegill Sunfish (Lepomis macrochirus)

1971 ◽  
Vol 28 (3) ◽  
pp. 449-451 ◽  
Author(s):  
J. Savitz
Keyword(s):  
Mathematical Description ◽  
Lepomis Macrochirus ◽  
Specific Dynamic Action ◽  
Nitrogen Excretion ◽  
Bluegill Sunfish ◽  
Protein Consumption ◽  
Dynamic Action ◽  
Excretion Rates

Nitrogen excretion rates increase with an increase in protein consumption levels. A mathematical description of this relation was formulated from the data. Estimates of the effect of specific dynamic action on nitrogen excretion were also calculated.

Effects of Temperature and Body Weight on Endogenous Nitrogen Excretion in the Bluegill Sunfish (Lepomis macrochirus)

1969 ◽  
Vol 26 (7) ◽  
pp. 1813-1821 ◽  
Author(s):  
Jan Savitz
Keyword(s):  
Body Weight ◽  
Lepomis Macrochirus ◽  
Nitrogen Excretion ◽  
Bluegill Sunfish ◽  
Effects Of Temperature ◽  
Excretion Rates ◽  
Very High

The effects of temperature and body weight on endogenous nitrogen excretion (ENE) rate were examined for fish acclimated at 7.2, 15.6, 23.9, and 29.4–32.2 C. Nitrogen excretion rates were very high at the highest temperature and decreased with a decrease in acclimated temperature from 29.4–32.2 C to 15.6 C. Nitrogen excretion rates were equal at 15.6 and 7.2 C. From these data, an estimate of maintenance protein for a population of bluegidl sunfish (Lepomis macrochirus) was calculated on a seasonal and yearly basis.

scholarly journals The “continuing” metabolism of nitrogen in animals

1935 ◽  
Vol 118 (811) ◽  
pp. 488-521 ◽  
Keyword(s):  
Order Reaction ◽  
Nitrogen Excretion ◽  
First Order ◽  
Low Level ◽  
Straight Line ◽  
Nitrogen Intake ◽  
Daily Excretion ◽  
The Difference ◽  
Zero Time ◽  
Logarithmic Relation

It has been known since the time of Voit that in passing from a high to a low level of nitrogen intake, or vice versa, there is a lag, which in rats, for example, may last as long as a month before equilibrium at the new low level is established. Martin and Robison (1922) pointed out that the logarithm of the difference between the daily nitrogen excretion at the low level, designated as x , and the daily excretion in the interval between the two levels, a, i. e ., log ( a-x ), plotted against time gives a straight line. The same relationship is demonstrable in the data of the experiment of Deuel, Sandiford, Sandiford, and Boothby (1928). This logarithmic relation indicates that the decomposition of the nitrogen represented by ( a - x ), which we shall term the continuing metabolism, resembles a first-order reaction. The following question arises out of this phenomenon, which, so far as the writers are aware, has been given little attention. “ Is the continuing metabolism suspended during the period when nitrogen equilibrium is being maintained by the ingestion of the larger quantity of protein, or does it persist at a rate indicated by the extrapolated value of log ( a-x ) to zero time ? ” If the second alternative be true, it follows that in the state of nitrogen equilibrium there is storage of a portion of the exogenous nitrogen corresponding to the extent of the continuing metabolism.

Tryptophan-Niacin Metabolism in Rat with Puromycin Aminonucleoside-Induced Nephrosis

2006 ◽  
Vol 76 (1) ◽  
pp. 28-33 ◽  
Author(s):  
Yukari Egashira ◽  
Shin Nagaki ◽  
Hiroo Sanada
Keyword(s):  
Body Weight ◽  
Urinary Excretion ◽  
Enzyme Activities ◽  
Treated Group ◽  
Control Group ◽  
Puromycin Aminonucleoside ◽  
Low Level ◽  
Key Enzyme

We investigated the change of tryptophan-niacin metabolism in rats with puromycin aminonucleoside PAN-induced nephrosis, the mechanisms responsible for their change of urinary excretion of nicotinamide and its metabolites, and the role of the kidney in tryptophan-niacin conversion. PAN-treated rats were intraperitoneally injected once with a 1.0% (w/v) solution of PAN at a dose of 100 mg/kg body weight. The collection of 24-hour urine was conducted 8 days after PAN injection. Daily urinary excretion of nicotinamide and its metabolites, liver and blood NAD, and key enzyme activities of tryptophan-niacin metabolism were determined. In PAN-treated rats, the sum of urinary excretion of nicotinamide and its metabolites was significantly lower compared with controls. The kidneyα-amino-β-carboxymuconate-ε-semialdehyde decarboxylase (ACMSD) activity in the PAN-treated group was significantly decreased by 50%, compared with the control group. Although kidney ACMSD activity was reduced, the conversion of tryptophan to niacin tended to be lower in the PAN-treated rats. A decrease in urinary excretion of niacin and the conversion of tryptophan to niacin in nephrotic rats may contribute to a low level of blood tryptophan. The role of kidney ACMSD activity may be minimal concerning tryptophan-niacin conversion under this experimental condition.

Low-level lead exposure: Are there harmful effects?

1983 ◽  
Vol 28 (1) ◽  
pp. 79-79
Author(s):  
Claire B. Ernhart
Keyword(s):  
Lead Exposure ◽  
Low Level ◽  
Harmful Effects
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