Evidence of the glyoxylate cycle in the liver of newborn rats.
RESULTS



BACKGROUND
It is generally accepted that the glyoxylate cycle exists in microorganisms and higher plants but absent in higher animals. the hypodhesis of the glyoxylate cycle in the tissues of higher animals with a high level of physiological activity was first proposed by Kondrashova and Rodionova in 1971. The goal of this work was yo verifv this in newborn rats, which possess a 2.5-fold hygher physiological activity and oxygen consumption rate than adult rats.


METHODS
Newborn (7-day-old) anradult 1 ats were used for this experiment. The activities of the key enzymes of the glyoxylate cocle (isecitrate lyse and nmalate synthase) were measured by HPLC and spectroscopic methods. The activities of isocitrate lyase and malate synthase were found in the liver homogenates prepared from newborn rats, but not from adult rats. The activities of the enzymes common to both the Krebs cycle and the glyoxylate cycle (citrate synthase, aconitase, and malate dehydrogenase) were 20-40% higher in newborn than in adult rats.


CONCLUSIONS
These data indicate the existence of the glyoxylate cycle in animal tissues.
Morgunov
Igor G
IG
Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Russian Federation.
Kondrashova
Maria N
MN
Kamzolova
Svetlana V
SV
Sokolov
Alexander P
AP
Fedotcheva
Nadezhda I
NI
Finogenova
Tatiana V
TV
D000154:Aconitate Hydratase / Q000378:metabolism; D000375:Aging / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn; D002851:Chromatography, High Pressure Liquid; D002950:Citrate (si)-Synthase / Q000378:metabolism; D002952:Citric Acid Cycle; D006038:Glyoxylates / Q000378:metabolism*; D007522:Isocitrate Lyase / Q000378:metabolism; D008099:Liver / Q000201:enzymology / Q000378:metabolism*; D008291:Malate Dehydrogenase / Q000378:metabolism; D008292:Malate Synthase / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar
D006038:Glyoxylates; D008291:Malate Dehydrogenase; D002950:Citrate (si)-Synthase; D008292:Malate Synthase; D007522:Isocitrate Lyase; D000154:Aconitate Hydratase; C031150:glyoxylic acid