Biomaterial Database

Effects of glucagon and other peptides on fixation of CO2 by rat liver mitochondria. 1975

I M Smith, and R C Haynes, and J F Harper

Glucagon and glucagon fragments from the carboxyl terminal end of the protein act at 0.01 to 0.1 mM concentrations on isolated rat liver mitochondria to sustain the rate of fixation of CO2 in the presence of pyruvate. The rate of decarboxylation of pyruvate is also increased by these substances. Similar effects are found with bacitracin, vanocomycin and cephalothin but not with any other of the proteins, peptides and antibiotics tested. The action of glucagon requires the presence of added magnesum ion. The addition of glucagon results in a better maintenance of adenosine triphosphate (ATP), and it leads to a greater degree of swelling of the mitochondria during the incubation. The effect of glucagon is partially mimicked by atractyloside, but it appears that glucagon is not exerting its effect by an atractyloside-like action. Added ATP obliterates the effect of added glucagon by sustaining fixation of CO2 However in incubations made in the presence of lower than usual levels of inorganic phosphate (2 mM vs. 8 mM) an effect of glucagon can be seen in the presence of ATP.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008274	Magnesium	A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
D008297	Male		Males
D008930	Mitochondria, Liver	Mitochondria in hepatocytes. As in all mitochondria, there are an outer membrane and an inner membrane, together creating two separate mitochondrial compartments: the internal matrix space and a much narrower intermembrane space. In the liver mitochondrion, an estimated 67% of the total mitochondrial proteins is located in the matrix. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p343-4)	Liver Mitochondria,Liver Mitochondrion,Mitochondrion, Liver
D008933	Mitochondrial Swelling	An increase in MITOCHONDRIAL VOLUME due to an influx of fluid; it occurs in hypotonic solutions due to osmotic pressure and in isotonic solutions as a result of altered permeability of the membranes of respiring mitochondria.	Giant Mitochondria,Megamitochondria,Mitochondrial Hypertrophy,Giant Mitochondrias,Hypertrophy, Mitochondrial,Megamitochondrias,Mitochondria, Giant,Mitochondrial Hypertrophies,Swelling, Mitochondrial
D010446	Peptide Fragments	Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.	Peptide Fragment,Fragment, Peptide,Fragments, Peptide
D010455	Peptides	Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are considered to be larger versions of peptides that can form into complex structures such as ENZYMES and RECEPTORS.	Peptide,Polypeptide,Polypeptides
D011773	Pyruvates	Derivatives of PYRUVIC ACID, including its salts and esters.
D002245	Carbon Dioxide	A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.	Carbonic Anhydride,Anhydride, Carbonic,Dioxide, Carbon
D003653	Decarboxylation	The removal of a carboxyl group, usually in the form of carbon dioxide, from a chemical compound.	Decarboxylations