THE ROLE OF THE ADRENAL GLAND IN THE CONTROL OF AMINO ACID INCORPORATION INTO PROTEIN OF ISOLATED RAT LIVER MICROSOMES

1960 ◽  
Vol 21 (2) ◽  
pp. 177-189 ◽  
Author(s):  
A. KORNER
Keyword(s):  
Amino Acid ◽  
Rat Liver ◽  
Liver Microsomes ◽  
Female Rats ◽  
Male Rats ◽  
Rat Liver Microsomes ◽  
Hypophysectomized Rats ◽  
Normal Rat ◽  
Secondary Result

SUMMARY 1. Microsomes, isolated from rat liver a day after adrenalectomy, incorporate more radioactive amino acid into their protein in vitro than microsomes from normal rat liver. This enhanced rate of incorporation progressively declines with time after adrenalectomy until it reaches a plateau level which is below the normal rate of incorporation. 2. Following adrenalectomy microsomes isolated from liver of male rats show a greater rise in incorporating ability than those from liver of female rats, and maintain it longer. 3. Most of the increased incorporation observed in the in vitro system soon after adrenalectomy of the rat, and most of the decreased incorporation observed in rats adrenalectomized for some time, results from alterations in the microsomes which change their ability to incorporate activated amino acids into proteins. 4. Treatment of rats with cortisol acetate results in an increase in the ability of liver microsomes to incorporate amino acid into protein. This heightened incorporating ability is probably a secondary result of the breakdown of extrahepatic tissue protein which is stimulated by cortisol. 5. Somewhat similar responses to acute adrenalectomy and to treatment with cortisol were found in hypophysectomized rats. 6. The protein anabolic response of adrenalectomized rats to treatment with insulin, and of adrenalectomized-hypophysectomized rats to treatment with insulin or growth hormone, is greater than that shown by rats which possess adrenal glands.

scholarly journals The Effect of (-)-Linalool on the Metabolic Activity of Liver CYP Enzymes in Rats

2016 ◽  
pp. S499-S504 ◽  
Author(s):  
K. NOSKOVÁ ◽  
G. DOVRTĚLOVÁ ◽  
O. ZENDULKA ◽  
R. ŘEMÍNEK ◽  
J. JUŘICA
Keyword(s):  
Rat Liver ◽  
Metabolic Activity ◽  
Systemic Treatment ◽  
Competitive Inhibition ◽  
Floral Scent ◽  
Liver Microsomes ◽  
Inhibitory Effect ◽  
Male Rats ◽  
Rat Liver Microsomes

(-)-Linalool is the major floral scent occurring mainly in families Lamiaceae, Lauraceae and Rutaceae and is the main active compound of lavender oil. The purpose of this study was to reveal the influence of subchronic systemic treatment with (-)-linalool on the metabolic activity of CYP2A, 2B, 2C6, 2C11 and 3A in rat liver microsomes (RLM). The second aim was to reveal possible inhibitory effect of (-)-linalool on CYP2C6 in vitro. Wistar albino male rats were treated with (-)-linalool intragastrically at the doses of 40, 120, and 360 mg/kg/day for 13 days. Treatment with (-)-linalool at the dose of 360 mg/kg increased the metabolic activity of CYP2A assessed with testosterone as a probe substrate. (-)-Linalool showed weak competitive inhibition of CYP2C6 in rat liver microsomes, with IC50 of 84 μM with use of diclofenac as a probe substrate.

scholarly journals Degradation of Stearoyl-Coenzyme A Desaturase: Endoproteolytic Cleavage by an Integral Membrane Protease

1998 ◽  
Vol 9 (12) ◽  
pp. 3445-3453 ◽  
Author(s):  
F. Scott Heinemann ◽  
Juris Ozols
Keyword(s):  
Rat Liver ◽  
Coenzyme A ◽  
Liver Microsomes ◽  
Integral Membrane Protein ◽  
Rat Liver Microsomes ◽  
Selective Degradation ◽  
Endoproteolytic Cleavage ◽  
Microsomal Membranes ◽  
Normal Rat

Stearoyl-coenzyme A desaturase (SCD) is a key regulator of membrane fluidity, turns over rapidly, and represents a prototype for selective degradation of resident proteins of the endoplasmic reticulum. Using detergent-solubilized, desaturase-induced rat liver microsomes we have characterized a protease that degrades SCD. Degradation of SCD in vitro is highly selective, has a half-life of 3–4 h, and generates a 20-kDa C-terminal fragment of SCD. The N terminus of the 20-kDa fragment was identified as Phe177. The cleavage site occurs in a conserved 12-residue hydrophobic segment of SCD flanked by clusters of basic residues. The SCD protease remains associated with microsomal membranes after peripheral and lumenal proteins have been selectively removed. SCD protease is present in normal rat liver microsomes and cleaves purified SCD. We conclude that rapid turnover of SCD involves a constitutive microsomal protease with properties of an integral membrane protein.

Induction of Cytochrome P-450-linked Monooxygenase System in Rat Liver Microsomes by Xiao-Chaihu-Tang

1996 ◽  
Vol 24 (02) ◽  
pp. 143-151 ◽  
Author(s):  
Taira Ohnishi ◽  
Hirohito Yoneyama ◽  
Tatushichiro Hamamoto ◽  
Toshihiko Ishida ◽  
Jirou Takahara ◽  
...  
Keyword(s):  
Rat Liver ◽  
Liver Microsomes ◽  
The Other ◽  
Female Rats ◽  
Male Rats ◽  
Monooxygenase System ◽  
Rat Liver Microsomes ◽  
Female Rat ◽  
Metabolic Rates ◽  
Cytochrome P 450

The administration of Xiao-Chaihu- Tang (TJ-9) for 2 weeks induced a 25% increase in the content of cytochrome P-450 in female rat liver microsomes, while the content in male rats remained unchanged. The enzymatic activities toward various xenobiotics were stimulated in female rats, the levels being in the range of 125-250% of those in the control rats. Among these xenobiotics, the metabolic rates for substrates of cytochrome P-450 2El were significantly enhanced in female rats. On the other hand, the activities toward various xenobiotics in male rats were unchanged. When 3-methylcholanthrene was given to rats for a week, the augmentation of cytochrome P-450 content and the stimulation ofxenobiotic metabolism were observed. However, co-administration ofTJ-9 did not alter the effect of 3-methylcholanthrene described above.

In vitro metabolism in Sprague–Dawley rat liver microsomes of forsythoside A in different compositions of Shuang–Huang–Lian

Fitoterapia ◽  
2011 ◽  
Vol 82 (8) ◽  
pp. 1222-1230 ◽  
Author(s):  
Wei Zhou ◽  
Liu-qing Di ◽  
Jin-jun Shan ◽  
Xiao-lin Bi ◽  
Le-tian Chen ◽  
...  
Keyword(s):  
Rat Liver ◽  
Liver Microsomes ◽  
In Vitro Metabolism ◽  
Rat Liver Microsomes ◽  
Sprague Dawley ◽  
Sprague Dawley Rat

scholarly journals In Vitro Characterization of Borneol Metabolites by GC--MS Upon Incubation with Rat Liver Microsomes

2008 ◽  
Vol 46 (5) ◽  
pp. 419-423 ◽  
Author(s):  
R. Zhang ◽  
C.-h. Liu ◽  
T.-l. Huang ◽  
N.-s. Wang ◽  
S.-q. Mi
Keyword(s):  
Rat Liver ◽  
Liver Microsomes ◽  
Rat Liver Microsomes ◽  
In Vitro Characterization

In Vitro Metabolism of E2, G2: Novel Bile Acid-Coupling Camptothecin Analogues, in Rat Liver Microsomes

2021 ◽  
Vol 16 ◽  
Author(s):  
Xiangli Zhang ◽  
Qin Shen ◽  
Yi Wang ◽  
Leilei Zhou ◽  
Qi Weng ◽  
...  
Keyword(s):  
Bile Acid ◽  
Phase I ◽  
Rat Liver ◽  
Deoxycholic Acid ◽  
Liver Microsomes ◽  
Intrinsic Clearance ◽  
Rat Liver Microsomes ◽  
Camptothecin Analogues

Background: E2 (Camptothecin - 20 (S) - O- glycine - deoxycholic acid), and G2 (Camptothecin - 20 (S) - O - acetate - deoxycholic acid) are two novel bile acid-derived camptothecin analogues by introducing deoxycholic acid in 20-position of CPT(camptothecin) with greater anticancer activity and lower systematic toxicity in vivo. Objective: We aimed to investigate the metabolism of E2 and G2 by Rat Liver Microsomes (RLM). Methods: Phase Ⅰ and Phase Ⅱ metabolism of E2 and G2 in rat liver microsomes were performed respectively, and the mixed incubation of phase I and phase Ⅱ metabolism of E2 and G2 was also processed. Metabolites were identified by liquid chromatographic/mass spectrometry. Results: The results showed that phase I metabolism was the major biotransformation route for both E2 and G2. The isoenzyme involved in their metabolism had some difference. The intrinsic clearance of G2 was 174.7mL/min. mg protein, more than three times of that of E2 (51.3 mL/min . mg protein), indicating a greater metabolism stability of E2. 10 metabolites of E2 and 14 metabolites of G2 were detected, including phase I metabolites (mainly via hydroxylations and hydrolysis) and their further glucuronidation products. Conclusion: These findings suggested that E2 and G2 have similar biotransformation pathways except some difference in the hydrolysis ability of the ester bond and amino bond from the parent compounds, which may result in the diversity of their metabolism stability and responsible CYPs(Cytochrome P450 proteins).

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