THE EFFECT OF BETAMETHASONE ON GLUCOSE PRODUCTION AND ON GLUCONEOGENESIS FROM AMINO ACIDS IN SHEEP

1974 ◽  
Vol 60 (3) ◽  
pp. 455-461 ◽  
Author(s):  
P. E. B. REILLY ◽  
E. J. H. FORD
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Plasma Glucose ◽  
Intramuscular Injection ◽  
Significant Proportion ◽  
Glucose Production ◽  
Entry Rate ◽  
Steroid Administration ◽  
Single Intramuscular Injection ◽  
Mean Glucose

SUMMARY Primed continuous infusions of tracer amounts of [U-14C]glucose and of [U-14C]labelled mixed amino acids were used to measure plasma glucose and amino acid entry rates and to obtain an index of the incorporation of amino acid carbon into glucose by sheep before and 24 h after a single intramuscular injection of betamethasone. Maximum hyperglycaemia occurred 24 h after administration of the steroid, but there was no significant change in arterial amino acid concentration. Mean glucose entry rate was significantly raised 24 h after steroid administration. The rate of incorporation of amino acid carbon into glucose also increased significantly. The increases in plasma glucose concentration and in glucose entry confirm the authors' previous results. The results also indicate that a significant proportion of the additional glucose entry is synthesized from amino acid carbon.

The effect of two synthetic steroids on plasma glucose concentration and total entry rate of glucose in sheep

1976 ◽  
Vol 87 (2) ◽  
pp. 417-421 ◽  
Author(s):  
Anoma Ranaweera ◽  
E. J. H. Ford
Keyword(s):  
Triamcinolone Acetonide ◽  
Plasma Glucose ◽  
Glucose Concentration ◽  
Intramuscular Injection ◽  
Plasma Glucose Concentration ◽  
Maximum Plasma ◽  
Entry Rate ◽  
The Mean ◽  
The Difference ◽  
Mean Glucose

SummaryPrimed continuous intravenous infusions of tracer amounts of [2·3H]gluscose were used to measure glucose entry rates before and after the administration of triamcinolone acetonide or trienbolone acetate to sheep eating 1200 g/day of chopped hay.The intramuscular injection of triamcinolone acetonide caused hyperglycaemia with a maximum plasma glucose concentration 24 h after the injection. Twenty-four hours after the injection of 0·5 mg/kg of steroid the mean glucose entry rate rose from 1·44 to 2·14 mg/min/kg. The difference between these means is significant (P < 0·02). Twenty-four hours after injecting 0·05 mg/kg of steroid the mean glucose entry rate had risen from 1·34 to 1·86 mg/min/kg. The difference between these means is significant (P < 0·05). The intramuscular injection of trienbolone acetate (0·5 mg/kg) had no effect on plasma glucose concentration or on glucose entry rate.These results are compared with the effect of betamethasone and are discussed in relation to the treatment of ketosis in cattle and sheep.

scholarly journals The effects of different dietary contents of protein on amino acid and glucose production and on the contribution of amino acids to gluconeogenesis in sheep

1971 ◽  
Vol 26 (2) ◽  
pp. 249-263 ◽  
Author(s):  
P. E. B. Reilly ◽  
E. J. H. Ford
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Protein Intake ◽  
Glucose Production ◽  
Portal System ◽  
Total Amino Acid ◽  
Entry Rate ◽  
The Best Approximation ◽  
Rate Of Absorption ◽  
Total Glucose

1. Free amino acid entry rates, rates of portal uptake of amino acids and rates of glucose synthesis from amino acids have been measured during the continuous intravenous infusion of [U-14C]-labelled mixed amino acids in six sheep receiving diets that supplied different amounts of protein.2. In four of these sheep and in one other, total rates of glucose production have been measured using continuous intravenous infusions of [U-14C]-labelled glucose.3. A signiiicant correlation was found between total amino acid entry rate ( Y mg/min.kg) and daily protein intake ( X g/kg): Y = 2·14+ 1·38X (r = 0·878, 0·02 > P > 0·01).4. A significant correlation was found between the rate of absorption of amino acids into the portal system ( Y mg/min.kg) and the daily protein intake ( X g/kg): Y = 0·58 + 0·58X (r = 0·884, 0·02 > P > 0·01).5. A highly significant correlation was found between total glucose production rates ( Y mglmin. kg) and daily protein intake ( X g/kg): and daily protein intake ( X g/kg): Y = 2.14+ 1.38X (r = 0·878, 0·02 > P > 0·01). Y = 0·375f0·702X (r = 0·866, 0·005 > P > 0·001).6. The mean proportional contribution to total amino acid entry made by portal absorption was 33·5 f 1·8 yo (six animals).7. A significant correlation was found between the rate of glucose production from amino acids (Y mg/min.kg) and the rate of entry of amino acids ( X mg/min.kg): Y = 0-189X-0·414 ( r = 0·84, 0·01 > P > 0·005).8. The best approximation of the proportion of glucose derived from amino acids was 28·16 f 5·1 % (six animals).9. The specific radioactivities of amino acids in liver, kidney and muscle did not approach those found in plasma during infusions of [U-14C]-labelled mixed amino acids of up to 6·75 h.

Extent of damage to amino acid availability of whey protein heated with sugar

1991 ◽  
Vol 58 (4) ◽  
pp. 431-441 ◽  
Author(s):  
Thérèse Desrosiers ◽  
Laurent Savoie
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Whey Protein ◽  
Significant Proportion ◽  
Protein Digestibility ◽  
Heating Time ◽  
Heat Treatments ◽  
Molar Ratio ◽  
Amino Acid Availability

SummaryThe effect of heat treatments, at various water activities (αw), on digestibility and on the availabilities of amino acids of whey protein samples in the presence of lactose was estimated by an in vitro digestion method with continuons dialysis. Four αw (0·3, 0·5, 0·7 and 0·97), three temperatures (75, 100 and 121 °C) and three heating periods (50, 500 and 5000 s) were selected. The initial lysine: lactose molar ratio was 1:1. Amino acid profiles showed that excessive heating of whey (121 °C, 5000 s) destroyed a significant proportion of cystine at all αw, lysine at αw 0·3, 0·5 and 0·7, and arginine at αw 0·5 and 0·7. At αw 0·3, 0·5 and 0·7, protein digestibility decreased (P < 0·05) as the temperature increased from 75 to 121 °C for a heating period of 5000 s, and as the heating time was prolonged from 500 to 5000 s at 121 °C. Excessive heating also decreased (P < 0·05) the availabilities of ail amino acids at αw 0·3, 0·5 and 0·7. The availabilities of lysine, proline, aspartic acid, glutamic acid, threonine, alanine, glycine and serine were particularly affected. Severe heating at αw 0·97 did not seem to favour the Maillard reaction, but the availabilities of cystine, tyrosine and arginine were decreased, probably as a result of structural modifications of the protein upon heating. Heating whey protein concentrates in the presence of lactose not only affected lysine, but also impaired enzymic liberation of other amino acids, according to the severity of heat treatments and αw.

Wool growth and sulfur amino acid entry rate in sheep fed roughage based diets supplemented with bentonite and sulfur amino acids

1989 ◽  
Vol 40 (4) ◽  
pp. 889 ◽  
Author(s):  
PD Fenn ◽  
RA Leng
Keyword(s):  
Amino Acids ◽  
Drinking Water ◽  
Amino Acid ◽  
Continuous Infusion ◽  
Basal Diet ◽  
Sulfur Amino Acid ◽  
Sulfur Amino Acids ◽  
Entry Rate ◽  
Wool Growth ◽  
Water Supplementation

In two experiments, sheep were offered a roughage-based diet supplemented with either cysteine or bentonite as a solid, or bentonite, cysteine or methionine added to their drinking water. Supplementation with cysteine as a solid had no effect on wool growth, while supplementation via drinking water had no effect on wool growth or cysteine entry rate into the blood. Supplementation with methionine via drinking water increased the entry rate of methionine into blood by 69% (P< 0.05) as measured by a continuous infusion of [35S]-methionine. This coincided with subsequent increases in wool growth of 16% (P< 0.05) compared to sheep fed a basal diet alone. Compared with the basal diet alone, supplementation with 30 g/day bentonite as a dry powder or 60 g/day as a suspension in drinking water increased wool growth by 19 and 20% respectively. Bentonite given as sole supplement did not increase the entry rate of either cysteine or methionine into the blood of sheep. When bentonite and sulfur amino acids were complexed or mixed, wool growth was not increased above that for bentonite or the amino acid alone.

EFFECT OF BETAMETHASONE ON THE PRODUCTION OF GLUCOSE FROM PROPIONATE BY SHEEP

1974 ◽  
Vol 62 (1) ◽  
pp. 51-57 ◽  
Author(s):  
E. J. H. FORD ◽  
J. G. WINCHESTER
Keyword(s):  
Amino Acids ◽  
Intramuscular Injection ◽  
Intravenous Infusions ◽  
Single Intramuscular Injection ◽  
Significant Change

SUMMARY Primed continuous intraruminal infusions of tracer amounts of [2-14C]propionate were used to measure propionate production and the incorporation of propionate carbon into glucose by six sheep on a diet of 1000 g chopped hay/day. Primed continuous intravenous infusions of [U-14C]glucose were used to measure the rate of glucose entry in the same sheep. The measurements were repeated 24 h after a single intramuscular injection of betamethasone. Maximum hyperglycaemia and a significant increase in glucose entry occurred after 24 h but there was no significant change in propionate production or in the synthesis of glucose from propionate. It is concluded that the increase in glucose entry must arise from substrates other than propionate such as amino acids.

Sulfur amino acid metabolism in the whole body and mammary gland of the lactating Saanen goat

1999 ◽  
Vol 50 (3) ◽  
pp. 413 ◽  
Author(s):  
J. Lee ◽  
R. J. Knutson ◽  
S. R. Davis ◽  
K. Louie ◽  
D. D. S. Mackenzie ◽  
...  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Mammary Gland ◽  
Amino Acid ◽  
Significant Proportion ◽  
Oxidation Products ◽  
Whole Body ◽  
Acid Uptake ◽  
Saanen Goat ◽  
Arterial Blood

Five multiparous Saanen goats in late lactation were infused with 35S-cysteine into the mammary gland via the external pudic artery. A further 2 goats were infused with 35S-methionine via the same artery and later with 35S-methionine into the jugular vein. Total uptake of cysteine from the arterial blood supply by the mammary gland was approximately 6% of the 35S-cysteine flux past the gland, whereas uptake of methionine was 30–40%. Total mammary uptake of cysteine was also lower than that of methionine when expressed as a percentage of whole body utilisation (6.5 and 14%, respectively). The uptake from the blood did not account for output in the milk for either cysteine or methionine. Both amino acids were highly conserved by the gland as shown by little release of any degraded constitutive protein amino acids and no evidence of oxidation products of either cysteine or methionine being released into the blood. Comparison of 35S activity in the milk from the infused and non-infused sides of the gland showed up to 10% trans-sulfuration of methionine to cysteine within the gland, none of which was exported in the venous drainage. Total ATP production by one side of the gland was 12.1 mol/day or 13 mmol/min.kg mammary tissue, of which 15% was required for gland protein synthesis. The experimental measurements from both the cysteine and methionine infusions were used to solve a model of gland amino acid uptake and partitioning. Modelling radioactivity of both amino acids in the blood, intracellular free pool, and milk protein suggested that a single intracellular pool cannot be the only source of amino acid for protein synthesis. The model also provides support for the hypothesis that a significant proportion of the uptake of at least some amino acids by the mammary gland is from intracellular hydrolysis of extracellularly derived peptides.

AMINOACIDURIA IN RATS AFTER TREATMENT WITH THE ETHYL ESTER OF GAMMA-BUTYROBETAINE

1960 ◽  
Vol 38 (1) ◽  
pp. 837-843 ◽  
Author(s):  
Esau A. Hosein ◽  
Margaret Smart ◽  
Kathleen Hawkins
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Muscular Dystrophy ◽  
Ethyl Ester ◽  
Chromatographic Analysis ◽  
Intramuscular Injection ◽  
Muscle Proteins

Previous workers have shown that the urine of patients with muscular dystrophy contains excessive amounts of amino acids. Using paper chromatographic analysis, these workers found that the amino acid methylhistidine is among those excreted in large amounts. Rats do not normally excrete methylhistidine, but in our experiments it was found that intramuscular injection of the ethyl ester of gamma-butyrobetaine into rats caused both the excretion of methylhistidine and an excessive aminoaciduria, presumably through the breakdown of muscle proteins.

scholarly journals Amino Acid Transport into Cultured McCoy Cells Infected with Chlamydia trachomatis

2000 ◽  
Vol 68 (9) ◽  
pp. 5439-5442 ◽  
Author(s):  
Angela Harper ◽  
Christopher I. Pogson ◽  
John H. Pearce
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Chlamydia Trachomatis ◽  
Amino Acid Transport ◽  
Equilibrium Concentration ◽  
Transport Systems ◽  
Acid Transport ◽  
Entry Rate ◽  
Great Capacity ◽  
Cationic Amino Acids

ABSTRACT Amino acid transport into McCoy cells infected with strains representative of the two major biovars of Chlamydia trachomatis has been studied to determine if uptake is increased during infection. Preliminary work suggested that the transport systems L, A/ASC (for neutral amino acid transport), N (for transport of Asn, Gln, and His) and y+ (for cationic amino acids) were present in McCoy cells. With lymphogranuloma venereum biovar strain 434, little difference in the influx of representative amino acids Trp, His, and Lys or the analogue 2-aminoisobutyric acid (AIB) was observed during infection. With trachoma biovar strain DK20, a small increase in the initial entry rate and equilibrium concentration of each amino acid was found. McCoy cells appear to have great capacity for concentrating amino acids, which might obviate the need for transport induction by chlamydiae under conditions favoring the growth of infectious organisms.

AMINOACIDURIA IN RATS AFTER TREATMENT WITH THE ETHYL ESTER OF GAMMA-BUTYROBETAINE

1960 ◽  
Vol 38 (8) ◽  
pp. 837-843 ◽  
Author(s):  
Esau A. Hosein ◽  
Margaret Smart ◽  
Kathleen Hawkins
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Muscular Dystrophy ◽  
Ethyl Ester ◽  
Chromatographic Analysis ◽  
Intramuscular Injection ◽  
Muscle Proteins

Previous workers have shown that the urine of patients with muscular dystrophy contains excessive amounts of amino acids. Using paper chromatographic analysis, these workers found that the amino acid methylhistidine is among those excreted in large amounts. Rats do not normally excrete methylhistidine, but in our experiments it was found that intramuscular injection of the ethyl ester of gamma-butyrobetaine into rats caused both the excretion of methylhistidine and an excessive aminoaciduria, presumably through the breakdown of muscle proteins.

scholarly journals Metabolism of urea in late pregnancy and the possible contribution of amino acid carbon to glucose synthesis in sheep

1970 ◽  
Vol 24 (4) ◽  
pp. 905-915 ◽  
Author(s):  
J. V. Nolan ◽  
R. A. Leng
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Late Pregnancy ◽  
Pool Size ◽  
Entry Rate ◽  
Plasma Urea ◽  
Upper Limit ◽  
Pregnant Sheep ◽  
Potential Availability ◽  
Glucose Synthesis

1. Metabolism of urea in non-pregnant and pregnant sheep (1–25 d from term) has been examined. Injections of [14C]urea were used to estimate urea entry rate, urea pool size and urea space in sheep given 1000 g of a diet of equal parts of crushed oats and chaffed lucerne hay (daya) and in the same sheep 4 d after the ration had been reduced to 250 g (dayb).2. On both experimental days (aandb), mean pool size was greater (14% on day α, 29% on dayb) and urea space was greater (54% on day α, 24% on dayb) in pregnant animals than in non-pregnant animals; mean plasma urea concentrations were lower (35%) in the pregnant animals on day a but were not significantly different on dayb.3. The entry rate of urea was similar in all the animals on daya, but was significantly higher (34%) in pregnant than in non-pregnant animals on dayb. There was a significant decrease in urea entry rate in both pregnant (33%) and non-pregnant (86%) animals on dayb.4. The rate of excretion of urea was lower (26% on daya, 35% on dayb) in pregnant animals, indicating a higher (31% on day α, 40% on dayb) rate of degradation of urea in the digestive tract of pregnant as compared with non-pregnant sheep.5. Measurements of urea entry rate have been used to calculate the upper limit of amino acid deamination in pregnant and non-pregnant sheep, and this has been used as an indication of the potential availability of amino acid carbon for glucose synthesis. It is suggested that, at a maximum, amino acids may have contributed the carbon required for 63 g/d and 52 g/d of glucose on daysaandbrespectively.

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