Estrogen-induced increase in phosphohexose isomerase activity in the rat uterus

Estrogen-Induced Increase in Phosphohexose Isonlerase Activity in the Rat Uterus

The effects

of administration

of estradiol-

17~ on the activity of phosphohexose isomerase have been studied in the rat titerus. In ovariectomized rats, the activity of uterine phosphohexose isomerase was decreased to 49 per cent when compared to that of normal, unoperated rats. A single injection of estradiol-17/3 caused a marked increase in the enzyme activity which was detectable in 4 hours (153 per cent) and reached a maximum level (246 per cent) 16 hours after adof the hormone. Doseministration response studies indicated that 0.50 pg. of estradiol/lOO Gm. was sufficient to induce a statistically significant increase in uterine phosphohexose isomerase activity (158 per cent). Enzyme activity was maximally elevated to 278 per cent with the 20 pg./100 Gm. dose. Treat-

ment of estradiol injected rats with actinomycin, puromycin or ethionine, inhibitors of RNA and protein synthesis. completely blocked estradiolthe induced increase in the activity of uterine phosphohexose isomerase. Methionine, given concurrently with ethionine caused a complete reversal of ethionine inhibition of estradiol-induced rise in phosphohexose isomerase activity. The results suggest that the estradiol-induced increase in uterine phosphohexose isomerase activity represents enzyme biosynthesis de novo. The data are discussed in the light of current views regarding biochemical mechanisms underlying estrogenic action in the rat uterus. (Metabolism 16: No. 0, March, 271-278, 1967)

Control HOURS

2 AFTER

4

8

IN. JECTION

16

24 OF

E STRADI

OL

SINt31.41,.

VALADAHES

AND

LINC

Fig. 2.-Effect of varying d oses ’ of estradiol-17p on uterine phosphohexose isomerase (dose-response study). Bars represent the III~;~IISand st;dartl errors of 0 wluea rats of IO-12 m~ariectoinized c,acli obtained lw pooling lIteri Front :3-4 I-ats. hllp” were gi\.erl a sii;glc injection of estradiol-I’iP ii) (loses wr\-ing from 0. I O-:30.0 pg. 100 (;in. and sacrificed after 16 11011~s.Eirz\mr ;Icti\-it\, \xis calcl~l;~tctl per 100 (Gun. TIIC Id\. weight aird expressed as pcrumtage~ of controlk taken as IO0 per wrh asterisks indicate sigilific;wt alterations statisticall\ different from \~Llllrs of tllct C’oIt1ro1 rats. (1’ =
lh.~l~~xose

isomcwse

121, 124 and dfects

uctivitv

105 pr

of c~thioninr

versed

by rthioniw

(221

pc’r crnt)

and

Thus,

niiir gest

synthc,sis

that

the

phoh~~xosr Thy

of

and/or followiiig control thw

c~xprini~nt

anv

s&d

onlv

port

to thk

of ukrine

;~pprwial~k

\vas

view

carrid

out.

wtinomycin studies

1,~ hlurllc~r horniom~s

HNA

and

wnts

wtrogenic

protck

co-work+’

activitv.

inliil,itioii

rcacwltlv rcsvcwecl

wtivitv

Of synthrsis

of cstroqcnic I

alouS

id cutain

1)iosvntlicsis. of s&l,lc-l
our

that

~idi;iinistratit,11 into

l
<;ol-ski

csstratliol

in rat uterus

data

the, suggrstion

1jrc’;111(l

c;~I~s~~(~

and

that

olww~atioi~s

l~hospl~ol~~xosc

ot

utcbriirr>

cwnpl<~tc~ly

lvith

prc\ious

arc’ ii1 lines \vith

1’r(L-

prcuuwrs

lwcwnt

in ukrine \I.ith

sup-

ill the, ;lcti\it\.

tllis

011 thcs isorncw~c~

on

phosph0-

that

ri~ki!’ 1~1 one’ of thcs prim;ir\

stilnllac+ioi~s

hormones.

oiltht>ir rcsccwt studic,s, a&on

of this

is l~~lic~~d

dclition~~l

l
trc~atment

ethos

iiicrcaasc.

in this kssucl

ill tllc~ rat

iii stcpa. First, cstrogcw target tissue, i.c*., uterus. wtivit\,

promvcin,

~iintl promvcin

r(i-

Furthermore,

of l~NA-l”)lvrnc.r~~s~,

h\,

to

and

yiizvmC

of

of

ant1 \fy’r(’ failed

as \vc,ll as pm‘omy~in that

th(, ntyri

activitv

lrncls

sho\ln

r~sponsw.““‘)”

tllca

aclmixiti~g

incwas[~

of DNA-cliwctcyl

cl~moiistrat~d

in the activitv

Such

incorporatiol~

of tlwse

of rstroSnl-intlu~~~l

fi&okinasr~

Bawd

thci

from

at the l&e1

his groiq~1i~2” lla\,e

Actinomycin

lw

actinomvcin

estrogen

and

ilr viva.

incwase could

inhibitor

c7i~vmc’

Accordingly.~

of wzvmc’

clrs nova

bvnthcsis

phos-

~~lios~~liolic~xos~~

proportions

obwrvation

wpscwts

in ukrinc,

Supernatants in carving

This

protc+n

stimulate>

Iwthio-

of prc-existing

~stroS~n-indL1~c.d

acwleration hail

a marked

lation

inhibits

II is ;I pvcrful

ckstropic

incrwsc

olwr\x~cl isoniwiw

puromvcin

rrprtd

that

tk nova.

consicl~wcl.

or inhil~ition

summation.

tlw

phosl~holiexos~

\\‘hereas \ioiis

that

c~stradiol inliihitioit

\\‘a

in utrrinca

furth(~r

\vc‘w mix&

activation

in the ~xpctd

\\ith

increases

inckcwcs

:~ssa~~~l for phosl~l~ol~esose~xos~isom(‘rasc

produce

treatd

of dhiollinc~

cluck to an activation

\vas

rc’-

on mrtisoiw ~ilicl rc&dingsug~iizviiws. lCi Thescn findings

svnthcssis

~,strt,R~n-induc~~~l

c.str~~diol-tre~it~~~l rats

wml~lrt~l\~

also liavc~ sliomm

hqxitic

06 im inhildor.

in vitro and

at

of ~tliioirinc~

mav lw tlu~ to enzvme

tlic rrmc;\al

arc

p2iosphofructo~ili~~s(~

estradiol-iliducctl

~oulcl liavc, lwrn

rwn~tinrd th(a inhihitor\~

injcckd comurr;~lItl\rcWrncd complrtV1;~

of rats

co-nwrkc~rs

important

ohwr\wl

that

activitv

that

iiicrcucs

r(~vcwal

uteriw

c4kts

of wveral

possibilit\r

in utui

nidiioninc~

\Vc~lx~r aid

prrwntlv

isoiiwr;~s~

isoiwraw

lw

svnthesis

can rc’vc’rsC thrs inhibitory

induced

~ii%vm~

lrvclohscyvcd

In a&lit&

of rats

~strogen-trc,~\t(~~l rats pliosl~hollc~xost~ isoni(wsc

cent ). A similar

of c,str~~diol-iiiduc~~l pviously.”

:3 groups

It is intcwsting

in

mdhioninc~,

to the

(228 per

alonr~

of thwc

on t,stradiol-inducc,~l

mrd~ionine.

with

in uteri

cent. ‘reqwctiwly.

that

r~ccptor this

utrrus iiit(wc+s

<&ski

protc,in

co-\\~orkc~rs2i

stay

;IS a rcwlt

intcwdiolI

invol\yhs

ha\.cs sll~gc~st~~(] t]lilt

consiclrrcyl

st;~r~,o-sl”.‘.it~~,ll~~

Tllcb sCcont1

primarv

aid

inki\‘ 1~5 arl)itraril\,

\\.itll ;i changy

of its intcwction is rc’po~~sil)lt~

;~s ()ccllrrillg

;k rcyy,l)tor

ill ttlc.

iu tllc- l)i()logic,;il \\ith

cLstrogc%It. It

for ;m i~l~rc~;~s(~itI g1~1.

c’osc’ m~tal~olisni, lipid, and ’ liN.4 svlltllcxsis. Tlrcwa authors” ha\ c’ suggrstc,tl that syntliclsis Of r,cdain sp~dic ciizvmc’s iIi;i\’ l)c~ ill\~ol\;~tl in iilc,rcylsillg t]lcbxc’ \.ital iwt~~holi~ procywc~s. sinccl c,ctrog[~i1-iiltlLl~(,~t rc~sl>o~~sty ;ir(’ ill1l,lO~!dYl

I:‘L‘lQIINt: I’HOSI’HOHEXOSE

ISOhlEIMSI~:

277

lw actinomycin and puromycin at a time when no c+fec% is noted on overall protein synthesis. Estradiol has been sho\vn to incrraw thcb activity of se\wal Ilterine enzvmes2:i.2i hut whether or not the olwxvecl increases represent c’nzvmc &thesis remains to 1)~ demonstrated. Previous studies by Wallas ani co-w&kerslzi have shown that glycolysis in isolatecl uterine muscle is grcaatlv enhanced hy treatmrnt of the rat \\ith estrogen. Our present obsc~vations on estradiol-induced increases in uterine phosphohexose isomerase. together with those reported earlier for l~l~ospl~ofructokinasr”-‘x art’ in agrectmcwt \\.ith thta above views of Corski and co-workers.“’ It is tempting to specwlate that the increased glycolysis observed in the rat uterus following cstrogrn treatment may be associated with an incrwwcl rate of synthesis of specific enzvrn~~s. Further studies on c,stladiol-induction of other uterine enzymes in\wlvc,cl in flucwr mctalx~lisni ;w curwntlv in progrws in this lal,oratorv. ACKNOWLEDGMENTS enc. ot ,,b (KIS) js gl.at&11 to I’I.ofcswr continilcd intrrrst. encowngen~rrlt for twhnic;ll assistance ant1 Dr.

(hxgc \C’rhr of Indiana rtlivcrsit! ;~ntl xlvivt~. Thth ;~llthors thnk Airs. Xhriette (;c~)rgr Howr clt \lrrck. Shat-p ;~rltl Doh~~rc~ for

gift< of .~c%incm~\.ci~l D. REFERENCES

for

lli\

%icdillski

ynt~r~~~~

1:3. \Vall;~s.

0..

~l’allu.

E.. antI

I.iikW,

I;.:

Ef+‘ect of oestratliol n~onolxmmatc. 011 the nWtal,olislr~ of rat lltcrinr~ mllscle. .kta Endocrinol. 10:201-21 1. 19Ti2. 14. Kennv.

F.

T.,

and

Flora,

Ii.

hl.:

In-

t\.rosin~-tr-~~~t(~~lll~~~r~lte dllction of transnminasc~ in rat liver. 1. Biol. Ch?111. 7:36:%99-~703, 1% 1 1.5. M:el)er, C:.. ant1 Singhal. K. I,.: Rtrl<~ of cnz~mcs it1 homeostasis \‘I. Elf’td of triamcinolonr antI 0thc.r strroitls on rnzymes involxd ill ~lucorleogenc~sis. 13iochem. 1’11arm:~~ol. I:i: 117:316. -.

1187. 1964. Banrrjee. <:.. untl Brcmdvilr. S. 13.: Selective intlnctiml ;mtl sllplxcssiolr of Ii\ t’r c1nx\.,11(’ I)ios\~nthvsis. :Zmer. J, Physiol. 2ob: 1:37-14i, 196-7.

17. IlerrarWn. A.. ;mtl hlllell~~r. (i. c.: Ellcct of estradiol on thr metalx~lisnr of \erine-3-C’-’ in s,lr\ il,irly: Iltcrine
1956. ler\,ell. K. I’.. DiniT, C. Ii.. ant1 ~lucllrr. C:. C.: E;~rlv t~lfecta of cstr;ldid

on

nllclric

acid

mc~t;~l~olisln

in

thr mt uterlls. J. Hiol. Chc~. 2:31: 94Yj-959. 1958. 19. \lueller, (G. C.. llerrancll, A.. ant1 Jvrvell. I;. I’.: Studies on th(L lllechxiism Prop. 40. -,

of action of fdrogens. Hvc. Hormone Krs. 14395-1339. 19.58. Y.: Thr Corski. J.? ant1 Aizawa,

role of protein avnthrsis rstrogen action. l’roc. NatI. IT, S. 47:104-169. 1961. 21.

ill (WI\ :\catl. SC;.

(kn&. J., Notelx)onr. 11’. I>., ant1 Kicolettt~. J. :\.: Estroi_‘cn control of