Free amino-nitrogen exchange across the hindquarters of fed and fasted sheep and pigs

1982 ◽  
Vol 99 (1) ◽  
pp. 91-104 ◽  
Author(s):  
Margaret I. Chalmers ◽  
I. Grant ◽  
F. White
Keyword(s):  
Amino Acids ◽  
Whole Blood ◽  
Free Amino Acids ◽  
Free Amino ◽  
Venous Blood ◽  
Amino Nitrogen ◽  
Growing Pigs ◽  
Net Uptake ◽  
Net Flux ◽  
Nitrogen Exchange

SUMMARYFree amino·N estimations were used to monitor the movement of free amino acids in blood passing through the hindquarters of sheep and growing pigs. The net uptakeor release of free amino·N was calculated from arterio-venous differences in the concentration of free amino·N measured in whole blood and plasma at short intervals of time.In both species the net change was an apparent release of free amino·N into venous blood. The release increased on fasting. Net uptake of free amino·N from blood was occasionally found at single sampling times due to loss from the cell compartment in sheep and from the plasma compartment in pigs. The uptake measured in whole blood was always less than in a single compartment of blood. The greatest fluctuation in free amino·N concentration occurred in the cells of aorta blood.It is concluded that both blood cells and plasma have independent roles in the net flux of free amino·N requiring determinations of amino acids in both whole blood and plasma to describe the exchange of blood free amino acids with tissue. A negative arteriovenous difference of free amino·N in blood across skeletal muscle is normal for healthy well-fed animals. Fasting increases the negativity.

Free amino -nitrogen used as a monitor for the uptake and movement of amino acids in sheep

1977 ◽  
Vol 89 (3) ◽  
pp. 541-550 ◽  
Author(s):  
Margaret I. Chalmers ◽  
I. Grant ◽  
Maureen G. Annand ◽  
F. White
Keyword(s):  
Amino Acids ◽  
Whole Blood ◽  
Free Amino ◽  
Vascular System ◽  
Amino Nitrogen ◽  
Portal Blood ◽  
Quantitative Calculation ◽  
Net Uptake ◽  
Low Nitrogen ◽  
Basal Ration

SummaryFree amino -N estimations were used to monitor the movement of amino acids in the vascular system of sheep. The net uptake of free amino-N by portal drained viscera was measured in whole blood and compared with the net gain in the plasma flow.In normally fed sheep eating dried grass, lucerne or silage the net gain of free amino -N in the plasma of portal blood contributed less than 80% to the total uptake in whole blood. When the protein component of the diet was added into the abomasum (casein supplement to a low nitrogen basal ration) the plasma contribution to the net gain in portal blood averaged 95%.The results suggest that the cells as well as the plasma are involved in the transport of amino acids in blood and that in ruminants all amino acids have to be measured in blood for a quantitative calculation of the absorption from portal drained viscera.

DIETARY EFFECTS ON THE CONCENTRATIONS OF FREE AMINO ACIDS IN PLASMA AND WHOLE BLOOD OF PIGS

1977 ◽  
Vol 57 (2) ◽  
pp. 295-303 ◽  
Author(s):  
M. O. KEITH ◽  
H. G. BOTTING ◽  
R. W. PEACE
Keyword(s):  
Amino Acids ◽  
Whole Blood ◽  
Free Amino Acids ◽  
Free Amino ◽  
Urea Cycle ◽  
Plasma Concentrations ◽  
Growing Pigs ◽  
Blood Concentrations ◽  
Natural Diet ◽  
Accurate Reflection

The concentrations of free amino acids in plasma and whole blood of growing pigs were examined following an overnight fast and at 2 and 5 h after eating either a semipurified diet containing casein or a natural grain-based commercial ration. The plasma:whole blood (P:B) ratio of the concentrations of threonine, proline and tyrosine changed significantly (P < 0.01) with time after feeding; methionine and lysine showed the same effect depending upon which diet was fed. Aspartic acid, citrulline, ornithine and histidine tended to show similar responses. No effect was observed on the ratios for other amino acids. Treatment effects on plasma:erythrocyte ratios were similar to those on P:B ratios. The semipurified diet resulted in increasing plasma and blood concentrations of most amino acids for 5 h after feeding whereas concentrations of most amino acids decreased after 2 h when the natural diet was fed. The natural diet appeared to stimulate greater urea cycle activity according to plasma concentrations of urea cycle metabolites. The data indicate that for some amino acids metabolic state affects plasma and whole blood concentrations differently, especially when a semipurified diet is fed. Whole blood concentrations of these amino acids are not an accurate reflection of plasma concentrations.

The effect of starvation and low nitrogen intakes on the concentration of free amino acids in the blood plasma and on the nitrogen metabolism in sheep

1970 ◽  
Vol 21 (5) ◽  
pp. 723 ◽  
Author(s):  
J Leibholz
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Dry Matter ◽  
Control Diet ◽  
Amino Nitrogen ◽  
Essential Amino Acids ◽  
Isoleucine Leucine ◽  
Plasma Urea ◽  
Low Nitrogen

Crossbred wethers were given a control diet (8 g nitrogen, 730 g dry matter daily) or a low nitrogen diet (0.5 g nitrogen, 520 g dry matter daily) or starved, for a 12 or 20 day experimental period. The concentrations of free serine, glutamine, glycine, alanine, histidine, and arginine in the plasma of the starved sheep decreased significantly while the concentrations of lysine, 3-methylhistidine, and isoleucine increased significantly. The ratio of essential to non-essential amino acids increased from 0.35 to 0.56 in the starved sheep. In sheep on the low nitrogen diet, the ratio of essential to non-essential amino acids in the plasma decreased from 0.40 to 0.27, with significant increases in the concentrations of glutanlic acid, glutamine, glycine, isoleucine, leucine, and 3-methylhistidine. Starvation and the low nitrogen diet both resulted in a reduction of the plasma urea concentrations. Starvation and the low nitrogen diet resulted in a 20-50 % reduction in the flow of saliva and a 40-78% increase in the concentration of total nitrogen. This resulted in no significant change in the daily secretion of nitrogen in the saliva. The concentration of urea in the saliva was increased by 3-54%. The concentrations of individual free amino acids in saliva are reported. The nitrogen content of the rumen was reduced, and after 7 days of starvation or on the low nitrogen diet all rumen nitrogen could be attributed to ammonia and free �-amino nitrogen.

The free Amino acid Pool of the Haemocytes of Carcinus Maenas (L.)

1972 ◽  
Vol 56 (2) ◽  
pp. 501-507
Author(s):  
P. D. EVANS
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Blood Sample ◽  
Free Amino Acid ◽  
Whole Blood ◽  
Free Amino Acids ◽  
Free Amino ◽  
Carcinus Maenas ◽  
Total Free Amino Acid ◽  
Whole Blood Sample

1. The presence of a large intracellular pool of free amino acids in the haemocytes of Carcinus maenas (L.) is described. It was found that 58 % of the total free amino acid concentration of a whole-blood sample was present in the cell fraction. 2. The blood-cell count for Carcinus was found to be around 33,000 cells/µl which corresponded to 1 % by volume of the whole-blood sample. Thus 58 % of the total free amino acid concentration of the blood sample is sequestered into 1 % of the total volume. 3. The pattern of the amino acid pool of the haemocytes is shown to differ from that of muscle and nervous tissue from Carcinus. In particular, the taurine molecule accounted for 50 % of the pool in the haemocytes. 4. Possible functions for the amino acids of the haemocyte pool are suggested and the results are discussed in relation to other studies on free amino acids in crustacean blood.

Serum concentrations of free amino acids in growing pigs exposed to diurnal heat stress fluctuations

2017 ◽  
Vol 69 ◽  
pp. 69-75 ◽  
Author(s):  
Miguel Cervantes ◽  
Nely Ibarra ◽  
Nydia Vásquez ◽  
Francisco Reyes ◽  
Ernesto Avelar ◽  
...  
Keyword(s):  
Amino Acids ◽  
Heat Stress ◽  
Free Amino Acids ◽  
Free Amino ◽  
Growing Pigs ◽  
Serum Concentrations
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