Hormonal Factors Altering Rhythmicity of Tyrosine-alphaketoglutarate Transaminase in Rat Liver<sup>1</sup>

Shambaugh, George E.; Warner, David A.; Beisel, William R.

doi:10.1210/endo-81-4-811

Cited by 62 publications

(10 citation statements)

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“…2.6.1.5) in the rat liver varies over a two-to fourfold range daily (Potter et al 1966). From low daytime values enzyme activity increases to peak several hours after darkness (Civen, Ulrich, Trimmer & Brown, 1967;Shambaugh, Warner & Beisel, 1967;Wurtman & Axelrod, 1967). This rise to an evening peak represents in-ACh, VAGUS AND TYROSINE TRANSAMINASE 423 by the inability of randomly selected animals to survive 1 week on tap water and confirmed after death in all animals by inspection of the retroperitoneal space for any remaining adrenal tissue.…”

Section: Introductionmentioning

confidence: 99%

Cholinergic regulation of hepatic tyrosine transaminase activity

Black¹,

Reis²

1971

The Journal of Physiology

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SUMMARY1. The cholinergic agent carbachol (0.5 mg/kg) produces within 2 hr a two-to threefold increase in the activity of hepatic tyrosine transaminase in the adrenalectomized fasted rat.2. The carbachol-evoked rise in enzyme activity is prevented by pretreatment with atropine.3. Cycloheximide, an inhibitor of protein synthesis, prevents the carbachol-evoked rise of enzyme activity; actinomycin D, an inhibitor of RNA synthesis, partially reduces it. 4. Atropine or unilateral (right or left) vagotomy suppresses the daily rhythm of tyrosine transaminase by attenuating the normal evening peak but not the normal lower daily levels of the enzyme.5. Electrical stimulation of the right vagus results in a significant elevation of tyrosine transaminase activity within 2 hr.6. The observations suggest that activity of vagal cholinergic nerves produces an RNA-dependent induction of hepatic tyrosine transaminase through a process requiring cholinergic-receptor stimulation. Intermittent activity of this vagal cholinergic system may contribute to the regulation of the daily rhythm in this enzyme.

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Section: Introductionmentioning

confidence: 99%

Cholinergic regulation of hepatic tyrosine transaminase activity

Black¹,

Reis²

1971

The Journal of Physiology

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“…3 (2,9); in addition, a diurnal rhythm for tyrosine transaminase recently has been observed by a number of investigators (10,11 ). Based on these findings, it is conceivable that feeding of protein or amino acids to patients in whom dietary nitrogen must be critically regulated, i.e.…”

Section: Resultsmentioning

confidence: 90%

Circadian periodicity of tryptophan metabolism

Rapoport¹,

Beisel²

1968

J. Clin. Invest.

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“…The second step (3 weeks of constant light) was introduced in the expectation that it would eliminate the rhythm. In previous studies (2)(3)(4), the approach was to remove the adrenal glands of rats already possessing the rhythm, then wait for a possible fade-out of periodicity. Only in the experiments of Shambaugh et al (4) did adrenalectomy produce an effect similar to that noted by us, whereas the effect was marginal in the studies of the other workers.…”

Section: Discussionmentioning

confidence: 99%

“…Changes in the range of oscillations as well as phase-shifts can be effected by hormonal (4) and dietary (1, 5, 6) manipulations. The effects on the rhythm are in accord with the well-established capacity of a number of hormones, and with the capacity of dietary means to alter the level of tyrosine aminotransferase in rat liver.…”

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confidence: 99%

The permissive role of cortisol in the regulation of rat liver tyrosine aminotransferase

Mavrides¹,

Lane²

1970

Can. J. Biochem.

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MAVWW, C., ~m LANE, E. A. The permissive rok of cortisol in the regulation of rat liver tyrosine aminotransferase. Can. J. Biochem. 48, 13-19 (1970).The daiIy rhythm in the activity of rat liver tyrosine aminotransferase was abolished after 3 weeks of constant illumination. The rhythm reappeared only partially in rats bilaterally adrenalectomized immediately after the 3-week period and returned to a cyclic lighting schedule. The failure of the enzyme rhythm to reappear fully did not seem to originate in dietary factors since food consumption and rate of growth were similar in the adrenalectomized and sham-operated control rats. Developmental studies showed that the adult rhythm was absent in rats up to 15 days old but present in 21-day-old rats. Although the rhythm appears to be generated in part by the rhythmic intake of dietary amino acids, a role for the endogenous glucocorticoids was suggested by the finding that physiological amounts of cortisol played a permissive role in the stimulation of enzyme activity by amino acids (casein hydrolysate) in adrenaIectomized rats. These amounts of cortisol greatly stimulated enzyme activity in rats fed a protein-free diet. A regulatory role for glucocorticoids based on this permissive action is envisaged in the daily rhythm of tyrosine aminotransferase.

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Hormonal Factors Altering Rhythmicity of Tyrosine-alphaketoglutarate Transaminase in Rat Liver¹

Cited by 62 publications

References 1 publication

Cholinergic regulation of hepatic tyrosine transaminase activity

Cholinergic regulation of hepatic tyrosine transaminase activity

Circadian periodicity of tryptophan metabolism

The permissive role of cortisol in the regulation of rat liver tyrosine aminotransferase

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Hormonal Factors Altering Rhythmicity of Tyrosine-alphaketoglutarate Transaminase in Rat Liver1

Cited by 62 publications

References 1 publication

Cholinergic regulation of hepatic tyrosine transaminase activity

Cholinergic regulation of hepatic tyrosine transaminase activity

Circadian periodicity of tryptophan metabolism

The permissive role of cortisol in the regulation of rat liver tyrosine aminotransferase

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Hormonal Factors Altering Rhythmicity of Tyrosine-alphaketoglutarate Transaminase in Rat Liver¹