Glucose polymerisation and cortisol

Vol. 10, No. 6, 1963

BIOCHEMICAL

AND BIOPHYSICAL

GLUCCJSE PGLYKEXISBTION H.Hile, Physiol.-Chem.

Received

February

Hilz,

1962)

on a simpler

der Universitat

concerning

polysaccharide 1960,

lead

model

rat

hormones.

Inspite

been made

tion

into

Weber, is

known

the

glucose

sol

the

of

#

some aspects

of

is

the

glucocorticoid

induction

(cf.

processes acid

1961;

Hiibener,

trsnsforma-

practically in

the

question et

and the

system

and their

1960; nothing

Latschinski

activities in

formation

amino

hormones

the

stimulated

for

enzyme

glycogen

strongly

test

the

problem

rle choose

glycogen

and others),

itself

the

that

way from

of

(cf.

fact

enzyme

concentrations

(G- 6-P)

tissue

Peigelson,

influence

therefore

on a1.,1961). corres-

glucose-6-

behavior

after

corti-

administration. Injection

lectomieed

of a suspension rats

concentration to

(cf.

of glucocorticoids

connective

which

on the

polymerisation

substrate

phosphate

of

1962,

the

We determined ponding

units

blatzelt,

about

liver,

a number

probable

glucose

1961;

Deutschland

synthesis.

as a biological

and although

habe

study

polysaccharide

by these

used

influence

of in

action,

Hamburg,

in

us to

formation

routinely

the

metabolism

glycogen

is

P. Arend

1963

12,

Experiments on the

AND COBTISOL

Y. Tarnowskiand

Institut

RESEARCH COMMUNICATIONS

a 40 fold

G-l-P

in

a single

of dose

cortisol leads

already

after

30 min.

increase

(fig.

1).

and finally

of glycogen

492

into

to an increase

which

A (less follows,

acetate

after

in

6 hrs.

drastic) whereas

adrena-

increase the

G-6-P-

amounts of

concentration

Vol. 10, No. 6, 1963

of

the

imr;iediate

(UDPG) the 0

BIOCHEMICAL

is

glycogen

strongly

glycogen

AND BIOPHYSICAL

precursor

decreased.

content

of

the

uridine

diphosphoglucose

glucose

rises

Blood liver

RESEARCH COMMUNICATIONS

also

starts

only

when

to increase.

I oc

zoog

4t

?-----

G-6-p

1

2

Pip.

1:

6

A

Theeffect

of cortisol

40

8

on the

system

Ip-s. post i+ctionem G-6-P

+

glycogen.

Male rats (-200 gm) were adrenalectomixed and injected with cortisol acetate suspension (2,5 mg/lOO gm), on the day,after a 14 hrs. fast. At the time indicated, they were decapitated after a blow on the head, the livers rapidly removed, and three homogenates from weighted pieces were prepared: One for enzyme detns. with 0.25 m sucrose-O.001 m BDTA, one for substrate tests with 4 % HClO , and one for glycogen phosphorylase with a solution contain&g 0.1 m NaF-0.005 m A detailed account of the methods employed will appear I%%&re (Biochem.2.) . The changes are expressed in $ of the starting point (adrenalect., without cortisol), rind all values are based on DNA content. Xach point represents 4-16 animals.

In the

contrast

activities

to the of

the

marked enzymes

changes

at

the

phosphoglucomutase, 493

substrate

levels,

UDPG-pyro-

Vol. 10, No. 6, 1963

BIOCHEMICAL

phosphorylase, little,

glycogen

if

any,

AND BIOPHYSICAL

phosphorylase,

increase

except

the

onset

measured

of

with

increase

apparently

the

have

shown,

our

(different)

labelled

that

but of

the

action

G-6-P

G-6-P

the

very

of

cortisol

concentration activator

from

should

very

primarily If

the

synthetase

present.

in

the

homogenate

as a basis,

elevated

But

addition,

in

itself,

G-6-P

is

The effectivity

Soon

nearly

after

1) Purified

indicate "G-6-P 1962).

of by the the

this

increase

in

of

the

system

rise

values

in of

activity determined

the

synthetase

be about

of

the

point.

lo-fold.

enzyme The overall

by a factor

the

our

the

would

this

than

increase

of

stimulation

G-6-P,

in

by increasing

therefore

behavior

this

an increase

combined

to less

as a rapid

the

for

shows a

stimulation

at

C-14we could

1) . Since

6 hrs.

doubled

may be increased

demonstrated

at

one observes

which

activity

the

With

of

amounts

one takes

niveau

synthetase.

levels,

act

et a1.(1959)

homogenate

first low

early,

of a cofactor

which

an

one has to

glycogen),

the

visible

of

by the

the

preparation

is

Here,

properties

activity

activated

such

As Leloir

into

G-6-P,

1959),

the

(incorporation

has the

small

fully

of

(UDPG)

Without

Leloir,

Nevertheless,

G-6-P.

assay

glucose"

(cf.

elevated

activity,

to explain

an activator of

enzyme

of glycogen. of

(GDPG-

significantly

G-6-P

sufficient

role

method

enzyme.

l/30

not

is

6 hrs.

formation

is

"active

definite,

the

is

G-6-P

liver

after

stimulating

demonstrate the

twofold

of

show only

synthetase

This

levels

and rapid

consider

synthesis.

saturating

nearly

efficient,

, which

glycogen

increased

and G-6-P*ase

glycogen

glycogen-1,4-transglucosylase) at

RESEARCH COMMUNICATIONS

of 20.

is

clearly

substrate

UDPG:

system

partially

is

synthetase behaves in a similar way. These results at the same time that in rat liver, practically no independent“ transglucosylase is present (cf.Friedman,

494

BIOCHEMICAL

Vol. 10, No. 6, 1963

deprived

from its

AND BIOPHYSICAL

"active

increasing

levels

merisation

runs faster

glucose"

inspite

of G-l-P are formed.

therefore

indicate

formation

of G-6-P (by an yet unknown mechanism).

creased

cortisol

of the fact

polymerisation

achieved

proper

by an increased

induces

primarily

is a secondary

activity

G-6-P,

the The in-

process

which is

of the enzyme synthetase

coming about in two ways: 1) by an elevated the activator

that

Apparently, the polyis made1) . Our results

than the supply

that

RESEARCH COMMUNICATIONS

concentration

and 2) by an (inductive?)

of

augmentation

of the enzyme protein 2) . The latter

point

the augmentation one is inclined hormonal

is caused.

as the result

of the synthetase

This fact,

the increase

it

Since,

after

sight,

of a direct in glycogen

can be suppressed

is not necessarily

however,

above.

At first rise

ethionine

in G-6-P is also suppressed,

of cortisol

by which factor

since the cortisol-induced

and the augmentation the explanation

to the question

of the synthetase to consider

action,

ethionine.

leads

by

in favor

of

administration,

the decisive

not only must be sought at an earlier

action

stage of

glycogen formation from protein: the failure of the different enzyme levels to rise (esp. synthetase, later on phosphoglucomutase, indirect

G-6-P'ase

consequence

one considers factor that

for

could also be interpreted

of the hormone action,

the G-6-P concentration

the glycogen

an increase

by injection

etc.)

then namely,

as the deciding

system. In fact, in G-6-P which was not hormonally

(or feeding)

formation

of glucose

as an cybernetic

we could show induced, but

to adrenalectomized

1) It is not clear yet if there is also an additional 2) UTP. A last proof for a true induction process is still although a number of tests make it very probable. 495

when

rats, need for lacking,

Vol. 10, No. 6, 1963

produced

BIOCHEMICAL

alterations

similar

AND BIOPHYSICAL

in the system G-6-P +

to the cortisol-induced

increase

in G-6-P concentration

in synthetase here,

too,

substrate

(measured

is followed

by a true

a metabolite

activation"

in an early it

rapid

increase And that

the

exhausted. may be described

best by the

induction":

stage of the glucose

probably

a primary

of G-6-P).

and "precursor

not only is an activator

enzyme synthetase;

levels

very

runs so effectively

UDPG becomes partially

terms "precursor chain,

too,

synthesis

these findings

glyoogen

ones. Here,

at saturating

the glycogen

At present,

RESEARCH COMMUNICATIONS

(G-6-P,

polymerisation

of the irreversibly

acting

also acts as an inducer

key

of the

same enzyme'). How far these phenomena bear connections to the action cortisol on mucopolysaccharide and glycoprotein synthesis, remains for

to be determined.

We thank Dr. C. Erich, Dr. H. Kirsig, carrying out some of the determinations. Mbit Untersttitzung

der Deutschen

and M. v. Gossler

Forschungsgemeinschaft.

BFXEXENCES Feigelson, Friedman,

Congress Biochem., Moscow 1961. P., V. Intern. D.L. and J. Larner, Biochim.Biophys.Acta 64, 185 (1962).

1) A definite

decision on induction" mechanism is system. The increase in could also be due, for level provocated by the

the existence of a true "precursor only possible with an isolated the (fully activated) synthetase instance, to an increased insulin rise in blood glucose. 496

of

Vol. 10, No. 6, 1963

BIOCHEMICAL

AND BIOPHYSICAL

RESEARCH COMMUNICATIONS

Hilz, H., J.Atheroscler.Res. 2, 252 (1962). Bile, H. and D. Utermann, Bi0chem.Z. B, 376 (1960). Hiibener, H.J., Hoppe-Seyler's Z.physiol.Chem. 322, 135 (1960). Leloir,L.F., J.Y. Olavarria, S.H. Goldenberg and H. Carminatti, Arch.Biochem.Biophys. 81, 508 (1959). Matschinski, F., U. Meyer and 0. Wieland, Klin.Wschr. 2, 818 (1961). Matzelt, D., A. Oriol-Bosch and K.D. Voigt, Bi0chem.Z. 222, 485 (1962). Weber, G., G. Banerjee and S.B. Bronstein, Biochem.Biophys.Res. Commun. 4, 332 (1961).

497