The induction of hepatic tyrosine α-ketoglutarate and phenylalanine pyruvate transaminases by glucagon

Civen, Morton; Trimmer, Betty M.; Brown, Charlesta B.

doi:10.1016/0024-3205(67)90029-x

Cited by 44 publications

(10 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The spectra for the two very different membrane preparations are remarkably similar; they are also similar to the optical rotatory dispersion spectra obtained by others with chloroplast-lamellae fragments (2) and to membrane preparations from tumor cells (3) and from mitochondria (4). The spectra are characteristic of the protein portion of the membrane, with only negligible contributions from the lipid constituents (1,5); and they indicate that the protein is in a partially helical conformation.…”

supporting

confidence: 82%

See 1 more Smart Citation

Feeding Schedule Alteration of Daily Rhythm in Tyrosine Alpha-Ketoglutarate Transaminase of Rat Liver

Fuller¹,

Snoddy²

1968

Science

View full text Add to dashboard Cite

Liver tyrosine alpha-ketoglutarate transaminase has a daily rhythm such that in rats fed on an unrestricted basis the activity is highest at approximately 11:00 p.m. In contrast, rats fed only from 8:00 a.m. to noon show a markedly different rhythm in the enzyme, with maximum activity at 11:00 a.m. Controlling the time of food intake seems to be a useful means of studying the mechanism of the daily changes in this enzyme.

show abstract

supporting

confidence: 82%

“…They were later in four volumes of 0.025 buffer (pH 7. 4 (2) which was carried out are nocturnal at 37 0C in a Gilford multiple-sample alteration in absorbance recorder. ne, commonly For rats with food available conatarate trans-tinuously ( Fig.…”

mentioning

confidence: 99%

Feeding Schedule Alteration of Daily Rhythm in Tyrosine Alpha-Ketoglutarate Transaminase of Rat Liver

Fuller¹,

Snoddy²

1968

Science

View full text Add to dashboard Cite

show abstract

“…Several investigators have in fact noted that glucagon induces a variety of amino acid transaminases. A possible explanation for our findings with phenylalanine and tyrosine may be drawn from the results of Civen et al 10 They found that glucagon induced tyrosine a-ketoglutarate transaminase much more rapidly (maximal effect about four hours) than phenylalanine pyruvate transaminase (maximal effect about twenty-four hours). The slight depression in blood phenylanine concentration we observed at one hour may have resulted from rapid uptake by tissues, 27 and lack of a sustained depression may reflect the slow induction of phenylalanine a-ketoglutarate transaminase.…”

Section: Discussionmentioning

confidence: 65%

Zinc Glucagon Depression of Blood Amino Acids in Rabbits

Bromer

Chance

1969

Diabetes

View full text Add to dashboard Cite

Single doses of glucagon and zinc glucagon were administered to fed rabbits and changes in blood glucose and total blood amino acids were measured. The concentration of amino acids was depressed longer with zinc glucagon !nhmif~M jHT mil ilrncilir fnrjiFjniTf twelve hmirrr>-rhnn wlth~ glucagon. A satisfactoryTaboratory method for comparingthe duration of action of preparations of glucagon was developed. Quantitative analyses showed that all of the common amino acids in plasma were depressed by zinc glucagon. Although 3.

show abstract

“…For animals used in metabolism experiments, glucagon injections were discontinued 18 h before the start of the experiment, with the objective of eliminating as much as possible any effect on phenylalanine metabolism of tyrosine-a-oxoglutarate aminotransferase induction, since it has been demonstrated that tyrosine oxidation in vivo may be increased after induction ofthis enzyme (Ip & Harper, 1973). Tyrosine-a-oxoglutarate aminotransferase in liver is rapidly induced by glucagon injection and decays to control values within 12h (Civen et al, 1967) ;p-hydroxyphenylpyruvate oxidase, the enzyme ultimately responsible for elimination of phenylalanine carboxyl carbon, is not induced by glucagon treatment (Civen & Brown, 1971;Ip & Harper, 1973). p-Chlorophenylalanine (0.11%, w/w) was administered in the diet at the expense of glucose monohydrate (Wapnir et al, 1970); treatment was continued for 1 week.…”

Section: Methodsmentioning

confidence: 99%

Effect of glucagon on phenylalanine metabolism and phenylalanine-degrading enzymes in the rat

Brand

Harper

1974

Biochemical Journal

View full text Add to dashboard Cite

Glucagon administered subcutaneously to rats for 10 days had no significant effect on liver phenylalanine hydroxylase activity, but induced liver dihydropteridine reductase more than twofold. In rats administered a phenylalanine load orally, glucagon treatment stimulated oxidation and depressed urinary phenylalanine excretion. These responses could not be related to an effect of glucagon on hepatic tyrosine-alpha-oxoglutarate aminotransferase activity. Even in rats with phenylalanine hydroxylase activity depressed to 50% of control values by p-chlorophenylalanine administration, glucagon treatment increased the phenylalanine-oxidation rate substantially. Although hepatic phenylalanine-pyruvate aminotransferase was increased tenfold in glucagon-treated rats, glucagon treatment did not increase urinary excretion of phenylalanine transamination products by rats given a phenylalanine load. Glucagon treatment did not affect phenylalanine uptake by the gut or liver, or the liver content of phenylalanine hydroxylase cofactor. It is suggested that dihydropteridine reductase is the rate-limiting enzyme in phenylalanine degradation in the rat, and that glucagon may regulate the rate of oxidative phenylalanine metabolism in vivo by promoting indirectly the maintenance of the phenylalanine hydroxylase cofactor in its active, reduced state.

show abstract

The induction of hepatic tyrosine α-ketoglutarate and phenylalanine pyruvate transaminases by glucagon

Cited by 44 publications

References 10 publications

Feeding Schedule Alteration of Daily Rhythm in Tyrosine Alpha-Ketoglutarate Transaminase of Rat Liver

Feeding Schedule Alteration of Daily Rhythm in Tyrosine Alpha-Ketoglutarate Transaminase of Rat Liver

Zinc Glucagon Depression of Blood Amino Acids in Rabbits

Effect of glucagon on phenylalanine metabolism and phenylalanine-degrading enzymes in the rat

Contact Info

Product

Resources

About