S-Space College of Medicine/School of Medicine (의과대학/대학원) Dept. of Medicine (의학과) The Seoul Journal of Medicine The Seoul Journal of Medicine Vol. 03 No.4 (1962)
흰쥐 간장절편에 있어서 C14-pyruvate의 대사과정에 관한 실험
Kinetics of Oxidative and Non Oxidative Metabolism of C14-labeled Pyruvate in Liver Slices of Normal Rats.
- Issue Date
- 서울대학교 의과대학
- Seoul J Med 1962;3(4):53-60
- Liver slices of rats were incubated with C'incubation mixtures of different concentrations.
Incubation was continued up to 5 hours. During the
incubation period, liver slices were exposed to fresh
media by hourly replacement of fresh incubation mixture.
Hourly samples, obtained through the replacement
of medium, were analyzed for pyruvate, lactate,
CO2 and specific activity (SA) of respiratory CO2•
Thirty two Sprague-Dawley rats were divided into
4 groups of 8 each. Different concentrations of pyruvate
incubation medium were used for each group.
Group 1 was incubated with pyruvate solution of 10
mg/dl, group 2 with 20mg/dl, group 3 with 30mg/dl
and group 4 with 40mg/dl pyruvate solution.
The following results were obtained.
1) Pyruvate disappearance rate, lactate accumulation
rate and total CO2 production rate decreased during
the initial 3 hours of incubation period and remained
approximately constant. Relative specific activity (R
SA) and CO2 produced from the medium C'increased exponentially during the early 3 hours and
reached to plateau values. These steady or plateau
values were used as the reference to compare the
metabolic rates between each group.
2) Pyruvate disappearance rates were 4. 2pM/hr/gm
of tissue in group 1, 7. 1 for group 2, 8. 8 for group
3 and 10 for group 4. Thus pyruvate disappearance
rates increased below 30mg/dl of pyruvate concentration
as the concentration of pyruvate in the incubation
medium increased and remained approximately
constant at concentration of greater than 30mg/dl.
3) Lactate accumulation rates for each group were
3. 3pM/hr/gm of tissue, 3. 5, 3. 8 and 4. 1 respectively,
There were little changes in lactate accumulation
rates despite the change in concentration of medium
pyruvate. 4) Total CO2 production rates for each group were
24. 4pM/hr/gm of tissue, 23.0, 26. 0 and 27. 3, respectively.
These rates also showed little changes as
shown in the lactate accumulation rate. RSA and
CO2 production rates derived from medium C'increased at concentration of medium pyruvate
below than 30mg/dl and remained approximately
constant at the concentration of C'than 30mg/dl. The percentage of CO2 derived from
medium C'for each group were 7. 1, 9. 4, 14.2 and 14. 7%,
respectively, while CO2 production rates derived from
medium C'0.7, 1.2 and 1. 3, respectively.
5) Fractions of pyruvate disappeared into respiratory
CO2 to total pyruvate disappearance, which is refered
to RPD, ,2, were 13.8, 10.1, 14.0 and 13.4%, respectively,
for each group and RPD lactate for each
group were 78.6, 49.3, 43.2 and 41. 0%. Therefore,
average of 92.4% of total pyruvate disappeared from
the medium in the group 1, 59.4% in the group 2,
57.2% in group 3 and 54.4% in group 4 were found
to be accounted for by the conversion of respiratory
CO2 and lactate accumulation.