SOME BIOCHEMICAL EFFECTS OF SPORIDESMIN

1965 ◽  
Vol 43 (7) ◽  
pp. 881-888 ◽  
Author(s):  
D. E. Wright ◽  
I. T. Forrester
Keyword(s):  
Guinea Pig ◽  
Succinate Oxidation ◽  
Biochemical Effects ◽  
Sheep Liver ◽  
Liver Homogenates ◽  
Nicotinamide Coenzymes

Sporidesmin inhibits in vitro the respiration of guinea pig and sheep liver homogenates in the presence of substrates which require nicotinamide coenzymes for their oxidation. Succinate oxidation was far less sensitive. Similar results were found with mitochondria.Slight swelling and release of 260 mμ absorbing compounds from mitochondria incubated in the presence of sporidesmin were observed. These results are discussed in relation to those reported elsewhere.

IN VITRO INHIBITION OF SUCCINATE OXIDATION BY ALFALFA SAPONIN

1970 ◽  
Vol 50 (1) ◽  
pp. 107-112 ◽  
Author(s):  
P. R. CHEEKE ◽  
J. E. OLDFIELD
Keyword(s):  
Enzyme Activity ◽  
Cumulative Effects ◽  
Succinate Oxidation ◽  
Saponin Content ◽  
Liver Homogenates ◽  
In Vitro Inhibition ◽  
Ethanol Extracts ◽  
Reaction Vessels

The effect of various levels of alfalfa saponin on the in vitro oxidation of succinate by rat liver homogenates was examined. With levels of 1 to 30 mg saponin per 100 mg liver tissue, the degree of inhibition increased from 3 to 90%. The inhibition was noncompetitive, since it was not overcome by increasing the substrate concentration. Mitochondria isolated from homogenates which had been incubated with saponin exhibited a reduced capacity to oxidize succinate of about the same magnitude as observed when saponin was added directly to the homogenates in the reaction vessels. Since the procedure for isolation of mitochondria should remove any unbound saponin, the reduction in oxidation capacity was attributed to binding of saponin to the succinoxidase enzyme. Thus, cumulative effects of saponin on enzyme activity might occur in vivo. Ethanol extracts of alfalfa were also found to inhibit in vitro succinate oxidation. Evidence is presented indicating that the inhibitory activity of these extracts was not due to their saponin content. Possible implications of the inhibition of succinate oxidation by alfalfa saponin are discussed.

VITAMIN A DEFICIENCY AND ISOPRENOID METABOLISM

1961 ◽  
Vol 39 (5) ◽  
pp. 855-861 ◽  
Author(s):  
W. E. J. Phillips
Keyword(s):  
Vitamin A ◽  
Guinea Pig ◽  
Vitamin A Deficiency ◽  
Metabolic Defect ◽  
Isoprenoid Metabolism ◽  
Metabolic Block ◽  
Liver Homogenates

Vitamin A deficiency in the intact rat evokes an increase in liver ubiquinone and the incorporation of mevalonate into ubiquinone and squalene. This aberration is caused by a metabolic block between squalene and cholesterol. The addition of vitamin A in vitro to vitamin A deficient liver homogenates does not influence the metabolic defect. The vitamin A deficient guinea pig does not exhibit an increase in liver ubiquinone or incorporation of mevalonate into ubiquinone or squalene, but the incorporation into sterols is enhanced.

Inhibition of Human and Animal Platelet Adhesiveness to Glass Bead Columns by Adenosine, Dipyridamole, Chlorpromazine and Acetylsalicylic Acid

1976 ◽  
Vol 36 (02) ◽  
pp. 401-410 ◽  
Author(s):  
Buichi Fujttani ◽  
Toshimichi Tsuboi ◽  
Kazuko Takeno ◽  
Kouichi Yoshida ◽  
Masanao Shimizu
Keyword(s):  
Guinea Pig ◽  
Acetylsalicylic Acid ◽  
Guinea Pigs ◽  
Glass Bead ◽  
Animal Species ◽  
Inhibitory Effect ◽  
Rabbit Platelet ◽  
Platelet Adhesiveness

SummaryThe differences among human, rabbit and guinea-pig platelet adhesiveness as for inhibitions by adenosine, dipyridamole, chlorpromazine and acetylsalicylic acid are described, and the influence of measurement conditions on platelet adhesiveness is also reported. Platelet adhesiveness of human and animal species decreased with an increase of heparin concentrations and an increase of flow rate of blood passing through a glass bead column. Human and rabbit platelet adhesiveness was inhibited in vitro by adenosine, dipyridamole and chlorpromazine, but not by acetylsalicylic acid. On the other hand, guinea-pig platelet adhesiveness was inhibited by the four drugs including acetylsalicylic acid. In in vivo study, adenosine, dipyridamole and chlorpromazine inhibited platelet adhesiveness in rabbits and guinea-pigs. Acetylsalicylic acid showed the inhibitory effect in guinea-pigs, but not in rabbits.

INHIBITION OF LIPOLYTIC ACTIVITY OF SYNTHETIC β1–24 AND β1–39 CORTICOTROPHIN BY ANTI-ACTH ANTISERUM

1966 ◽  
Vol 51 (1) ◽  
pp. 88-94 ◽  
Author(s):  
A. Villanueva ◽  
S. J. H. Ashcroft ◽  
J. P. Felber
Keyword(s):  
Guinea Pig ◽  
Lipolytic Activity ◽  
Peptide Hormones ◽  
Fat Pad ◽  
Double Antibody ◽  
Epididymal Fat ◽  
Antibody Complex ◽  
Radio Immunoassay ◽  
Antigen Antibody

ABSTRACT The synthetic ACTH peptides β1–39 and β1–24 stimulated lipolysis as determined by the rat epididymal fat pad in vitro. The stimulating effect of these peptides was diminished by prior incubation of the peptides with antibodies produced by the guinea-pig against ACTH. The stimulating effect of these hormones was also diminished by the double antibody system used in the radio-immunoassay of ACTH and other peptide hormones, in which incubation with antiserum is followed by precipitation of the antigen-antibody complex by rabbit anti-guinea-pig-γ-globulin.

Die Bedeutung der Homogenisationsart und -intensität für die Größe und Konstanz der Sauerstoffaufnahme von Meerschweinchen-Leberhomogenat / The Influence of Mode and Intensity of Homogenization on the Absolute Value and Stability of Oxygen Consumption of Guinea Pig Liver Homogenates

1977 ◽  
Vol 32 (11-12) ◽  
pp. 908-912 ◽  
Author(s):  
H. J. Schmidt ◽  
U. Schaum ◽  
J. P. Pichotka
Keyword(s):  
Oxygen Uptake ◽  
Guinea Pig ◽  
Measuring Time ◽  
Pig Liver ◽  
Absolute Value ◽  
Modified Method ◽  
Simultaneous Measurements ◽  
Liver Homogenates ◽  
The Absolute ◽  
Guinea Pig Liver

Abstract The influence of five different methods of homogenisation (1. The method according to Potter and Elvehjem, 2. A modification of this method called Potter S, 3. The method of Dounce, 4. Homogenisation by hypersonic waves and 5. Coarce-grained homogenisation with the “Mikro-fleischwolf”) on the absolute value and stability of oxygen uptake of guinea pig liver homogenates has been investigated in simultaneous measurements. All homogenates showed a characteristic fall of oxygen uptake during measuring time (3 hours). The modified method according to Potter and Elvehjem called Potter S showed reproducible results without any influence by homogenisation intensity.

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