THE EFFECT OF FASTING ON ESTERIFICATION OF PALMITATE BY RAT LIVER IN VITRO

1966 ◽  
Vol 44 (1) ◽  
pp. 129-140 ◽  
Author(s):  
Bernard Rubenstein ◽  
David Rubinstein
Keyword(s):  
Rat Liver ◽  
Incubation Medium ◽  
Intact Cell ◽  
Glycerol Kinase ◽  
Glycerophosphate Dehydrogenase ◽  
Liver Slices ◽  
Liver Homogenates

The ability of liver slices from rats fasted 48 hours to esterify palmitate-1-14C is about half of that of slices from fed animals. The same effect can be observed in homogenates of liver freed of nuclei, either with or without mitochondria. In both preparations, the synthesis of triglycerides is chiefly affected. The decrease in esterification by homogenate supernatants containing microsomes from fasted animals can be overcome by using increased amounts of ATP or an ATP generator and NaF in the incubation medium. The ATPase responsible for the higher ATP requirement in liver homogenates from fasted animals is Mg++-dependent. Higher concentrations of ATP inhibit esterification by mitochondrial preparations. Incorporation of both palmitate-9-10-3H and of glycerol-1-3-14C is reduced to the same extent for each compound in slices from fasting animals. Glycerol kinase and α-glycerophosphate dehydrogenase are both unaffected by 48 hours' fasting. It is concluded that the decrease in ATP from the activation of ATPase is responsible for the decreased esterification in the intact cell.

IN VITRO STUDIES ON THE BIOSYNTHESIS OF UBIQUINONE

1960 ◽  
Vol 38 (10) ◽  
pp. 1105-1115 ◽  
Author(s):  
W. E. J. Phillips
Keyword(s):  
Rat Liver ◽  
Intestinal Mucosa ◽  
Mevalonic Acid ◽  
In Vitro Studies ◽  
Detectable Amount ◽  
Exogenous Factor ◽  
Liver Slices ◽  
Liver Homogenates ◽  
Isolated Tissues

Radioactive ubiquinone can be isolated from rat liver following intraperitoneal injections of C14-acetate or mevalonic acid. No detectable amount of radioactive ubiquinone could be isolated from liver homogenates, liver slices, or intestinal mucosa incubated in vitro with C14-acetate or mevalonic acid. The possible requirement of isolated tissues for an exogenous factor is discussed.

In- Vitro Hepatotoxicity of Three Dichlorobenzene Isomers in Human Liver Slices

1991 ◽  
Vol 10 (5) ◽  
pp. 357-363 ◽  
Author(s):  
Robyn Fisher ◽  
John Barr ◽  
Charles F. Zukoski ◽  
Charles W. Putnam ◽  
I. Glenn Sipes ◽  
...  
Keyword(s):  
Animal Models ◽  
Rat Liver ◽  
Incubation Medium ◽  
Human Liver ◽  
Rank Order ◽  
Liver Slices ◽  
Ultimate Question ◽  
Human Liver Slices ◽  
Krebs Henseleit Buffer

1 The cytotoxicity of dichlorobenzenes in cultured rat liver slices has previously been shown to be strain specific and biotransformation related. 2 In order to extrapolate animal models to humans, the dichlorobenzenes were incubated with human liver slices to try to clarify their hepatotoxic potential in man. 3 The degree of hepatotoxicity observed with the dichlorobenzenes depended on whether Waymouth's or Krebs-Henseleit was used as the incubation medium. 4 All three dichlorobenzenes (1 mM) produced no significant differences from control when incubated in Waymouth's medium. However, in the Krebs-Henseleit buffer there was a substantial increase in cytotoxicity. 5 In both incubation mediums the dichlorobenzene isomers exhibited the following rank order 1,3-DCB > 1,2-DCB > 1,4-DCB. 6 1,2-dichlorobenzene hepatotoxicity was blocked by metyrapone, 1,3-dichlorobenzene toxicity was blocked by SKF 525-A and neither one of these inhibitors could block the 1,4-dichlorobenzene cytotoxicity. 7 The use of human liver tissues to evaluate potential toxicants merits consideration since the hepatotoxicity of xenobiotics and drugs in man is the ultimate question.

IN VITRO STUDIES ON THE BIOSYNTHESIS OF UBIQUINONE

1960 ◽  
Vol 38 (1) ◽  
pp. 1105-1115 ◽  
Author(s):  
W. E. J. Phillips
Keyword(s):  
Rat Liver ◽  
Intestinal Mucosa ◽  
Mevalonic Acid ◽  
In Vitro Studies ◽  
Detectable Amount ◽  
Exogenous Factor ◽  
Liver Slices ◽  
Liver Homogenates ◽  
Isolated Tissues

Radioactive ubiquinone can be isolated from rat liver following intraperitoneal injections of C14-acetate or mevalonic acid. No detectable amount of radioactive ubiquinone could be isolated from liver homogenates, liver slices, or intestinal mucosa incubated in vitro with C14-acetate or mevalonic acid. The possible requirement of isolated tissues for an exogenous factor is discussed.

Studies on the induction of rat hepatic CYP1A, CYP2B, CYP3A and CYP4A subfamily form mRNAs in vivo and in vitro using precision-cut rat liver slices

Xenobiotica ◽  
2003 ◽  
Vol 33 (5) ◽  
pp. 511-527 ◽  
Author(s):  
C. Meredith ◽  
M. P. Scott ◽  
A. B. Renwick ◽  
R. J. Price ◽  
B. G. Lake
Keyword(s):  
Rat Liver ◽  
Liver Slices

Substrate specificity of iodothyronine 5′-deiodinase in rat liver homogenates and its requirements of divalent cations in vitro

Life Sciences ◽  
1986 ◽  
Vol 38 (24) ◽  
pp. 2231-2238 ◽  
Author(s):  
Shinya Kobayshi ◽  
Yan Gao ◽  
Richard L. Ong ◽  
Constance S. Pittman
Keyword(s):  
Substrate Specificity ◽  
Rat Liver ◽  
Divalent Cations ◽  
Liver Homogenates

Metabolism in vitro of n-methylamphetamine with rat liver homogenates

1977 ◽  
Vol 26 (11) ◽  
pp. 1043-1049 ◽  
Author(s):  
Ronald T. Coutts ◽  
Susan H. Kovach
Keyword(s):  
Rat Liver ◽  
Liver Homogenates

Insulin stimulus of leucine incorporation into frog liver protein

1962 ◽  
Vol 203 (4) ◽  
pp. 687-689 ◽  
Author(s):  
J. C. Penhos ◽  
M. E. Krahl
Keyword(s):  
Amino Acid ◽  
Rat Liver ◽  
Leucine Incorporation ◽  
Liver Protein ◽  
Amino Acid Incorporation ◽  
Insulin Effect ◽  
Acid Incorporation ◽  
Liver Slices ◽  
Stimulation Of

Slices prepared from livers of bull frogs ( Rana catesbiana), pancreatectomized and/or hypophysectomized 7 days before, were incubated 2 hr in frog Ringer-bicarbonate solution at 25 C. Incorporation of leucine-1-C14 into protein was subnormal in the pancreatectomized series. The addition of insulin in vitro, with glucose also present in the medium, produced a significant ( P < 0.01) stimulation of amino acid incorporation in the following series: livers from normal fed animals; livers from animals pancreatectomized 7 days before; and livers from animals pancreatectomized and hypophysectomized 7 days before. Neither insulin nor glucose alone gave a significant effect. These results therefore confirm and extend those obtained with rat liver slices showing that insulin can stimulate amino acid incorporation into protein when added directly to liver. The effect is relatively greatest with livers from animals pancreatectomized 7 days before; the insulin effect does not depend on the presence of the pituitary, as it is obtainable with livers from animals hypophysectomized and pancreatectomized 7 days previously.

scholarly journals Aqueous Extracts of Teucrium polium Possess Remarkable Antioxidant Activity In Vitro

2006 ◽  
Vol 3 (3) ◽  
pp. 329-338 ◽  
Author(s):  
Predrag Ljubuncic ◽  
Suha Dakwar ◽  
Irina Portnaya ◽  
Uri Cogan ◽  
Hassan Azaizeh ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Antioxidant Activity ◽  
Rat Liver ◽  
Antioxidant Properties ◽  
Liver Homogenate ◽  
Plasma Oxidation ◽  
Teucrium Polium ◽  
Liver Homogenates ◽  
Β Carotene

Teucrium poliumL. (Lamiaceae) (RDC 1117) is a medicinal plant whose species have been used for over 2000 years in traditional medicine due to its diuretic, diaphoretic, tonic, antipyretic, antispasmodic and cholagogic properties. The therapeutic benefit of medicinal plants is often attributed to their antioxidant properties. We previously reported that an aqueous extract of the leaves and stems of this plant could inhibit iron-induced lipid peroxidation in rat liver homogenate at concentrations that were not toxic to cultured hepatic cells. Others have reported that organic extracts of the aerial components of this plant could inhibit oxidative processes. Against this background, we felt further investigation on the antioxidant action of the extract ofT. poliumprepared according to traditional Arab medicine was warranted. Accordingly, we assessed (i) its ability to inhibit (a) oxidation of β-carotene, (b) 2,2′-azobis(2-amidinopropan) dihydrochloride (AAPH)-induced plasma oxidation and (c) iron-induced lipid peroxidation in rat liver homogenates; (ii) to scavenge the superoxide ($${\hbox{ O }}_{2}^{\bullet -}$$) radical and the hydroxyl radical (OH•); (iii) its effects on the enzyme xanthine oxidase activity; (iv) its capacity to bind iron; and (v) its effect on cell glutathione (GSH) homeostasis in cultured Hep G2 cells. We found that the extract (i) inhibited (a) oxidation of β-carotene, (b) AAPH-induced plasma oxidation (c) Fe2+-induced lipid peroxidation in rat liver homogenates (IC50 = 7 ± 2 μg ml−1); (ii) scavenged $${\hbox{ O }}_{2}^{\bullet -}$$(IC50 = 12 ± 3 μg ml−1) and OH• (IC50 = 66 ± 20 μg ml−1); (iii) binds iron (IC50 = 79 ± 17 μg ml−1); and (iv) tended to increase intracellular GSH levels resulting in a decrease in the GSSG/GSH ratio. These results demonstrate that the extract prepared from theT. poliumpossesses antioxidant activityin vitro. Further investigations are needed to verify whether this antioxidant effect occursin vivo.

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