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Glucose metabolism in young rat skin
Glucose SEYMOUR
Metabolism
H. PO?\IEKXNTZ
in Young SND
MURIEL
Rat
Skin’
T. XS130RNSE;“r’
l-l!)
ii, 1
I Ii
,I /I 0.:j!) ,x3 o.o
‘t 23 20
, Ii0 Ii:3
‘/ 2.7 ”-. 4
0,s I .o O.-I 1 :< 0.;
I -1; 50
1i’l.S Iill. I:lli Ii11 104
‘, !l.li Ill
71 Sl S" !Ih IOi !)I 7.5 ! I$ !I5
T11c data in ‘l’abl<~ III intlicatc that in both experiments a minimum of 75c;Z of tlie total counts in t,hc c~tlicr vstrnct occurred in lactic aclitl. Tritll most of tlic. rcmnindcr in the ncctic acid and a small amount, in formic acid. Tf lactate were synthcGzcd via the I~mhdcn-~Iererllof patlln-a?- its maximum q1wific~ activity woulfl IJ~ 54X counts/min. ,‘pmol(, ( 10,900,/2) . The tnblv sl~ows that, cwcl)t for one sainplc the l:tct:rte:: were dilutctl 1~s::tlixn 375’1 by entlogcnous synthesis. Tn l?sl)t. 1 the ~pccifit nctivit,ies of the samples of acctatc~ and formate TWX considcrnblv IOU-er than the c*orrcsi)onding wn~plw in T;:sl)t 2. These tliffcrcnccs were caused ma,inly bp a rclatiwly large endogenous production of acetntc and formatc in Espt. 1 rather than by an increased conrersion of glurosc carbon to awtatr and formatc in Espt. 2. An csamination of Tables II and IT1 rercnls also that carbons I :rnd 6 of glucose ~vei’t‘ wnvcrt,ed about cqunlly to t,lle major frartions and to the different acids. Table ITT shows the distribution of C” in tlic sninplrs of lnctntc of T+q’t. 2. Froln both glucose-l-C’” and glucose-6-C’” virtunll\- all of the Cll- was in t,hc mcthgl carbon with little activity in carbons 1 and 2. The socaifir sdivit,ies of t.he free amino
‘l’l~c~ opcrntion of the citric acid cycle in:r\- IJCinfcrrcd frown the isolation of rnclioactive gltltamatc~ an(l aspartat,c:. This suppoAtion lw been confirmed by later csperinicnts (26 I in wliicli the specific a&vit> of CO, and information from the tlegrndation of citrate, malate: glutamate, aspnrtatc~, and svrine have shovn thnt the cit,ric acxid cycle is an impoltant clement in tlic osidative reactions of rat skin. LIore Cr40, was produced from gluc~osc~l-Cl4 than from ~IUCOSC-fXY4. However. the ratio c~hnnged during the incubation from 4.7 at 1 hr. to about 2 at 3 and 5 11r. The CIWZ tlata in thcsc csprriments arc) in gcncr:~l :tg~~c~~inontwith the results of Freinkc1 n-itll lrulr~an lwt-mortem skin 1141. In the roac*tion:: of the l?mbdcn-?\lcycrhof pathway and Gtric acicl cycle both the C-t ant1 (‘-6 1)ositions of gluroSc arc coilr-crtetl to Inc~tllpl ~1’Oll~E of pylYwntc :mrt I:LCt:lt~P and :II’O tllcrcufter metabolized identically. Chnri1ctc~ri~tics of the pentose cycle are the 105~ of C-l of glucose as CO, and the diffcrctrt metabolism of C-l and C-6. Frcinlie1 estim:tt,cd the percentages of gluroso mrtabolizcd via the pentose cycle and T-in
3. 4. 5. 6. 7. 8. 9. 10.
Metabolism
H. PO?\IEKXNTZ
in Young SND
MURIEL
Rat
Skin’
T. XS130RNSE;“r’
l-l!)
ii, 1
I Ii
,I /I 0.:j!) ,x3 o.o
‘t 23 20
, Ii0 Ii:3
‘/ 2.7 ”-. 4
0,s I .o O.-I 1 :< 0.;
I -1; 50
1i’l.S Iill. I:lli Ii11 104
‘, !l.li Ill
71 Sl S" !Ih IOi !)I 7.5 ! I$ !I5
T11c data in ‘l’abl<~ III intlicatc that in both experiments a minimum of 75c;Z of tlie total counts in t,hc c~tlicr vstrnct occurred in lactic aclitl. Tritll most of tlic. rcmnindcr in the ncctic acid and a small amount, in formic acid. Tf lactate were synthcGzcd via the I~mhdcn-~Iererllof patlln-a?- its maximum q1wific~ activity woulfl IJ~ 54X counts/min. ,‘pmol(, ( 10,900,/2) . The tnblv sl~ows that, cwcl)t for one sainplc the l:tct:rte:: were dilutctl 1~s::tlixn 375’1 by entlogcnous synthesis. Tn l?sl)t. 1 the ~pccifit nctivit,ies of the samples of acctatc~ and formate TWX considcrnblv IOU-er than the c*orrcsi)onding wn~plw in T;:sl)t 2. These tliffcrcnccs were caused ma,inly bp a rclatiwly large endogenous production of acetntc and formatc in Espt. 1 rather than by an increased conrersion of glurosc carbon to awtatr and formatc in Espt. 2. An csamination of Tables II and IT1 rercnls also that carbons I :rnd 6 of glucose ~vei’t‘ wnvcrt,ed about cqunlly to t,lle major frartions and to the different acids. Table ITT shows the distribution of C” in tlic sninplrs of lnctntc of T+q’t. 2. Froln both glucose-l-C’” and glucose-6-C’” virtunll\- all of the Cll- was in t,hc mcthgl carbon with little activity in carbons 1 and 2. The socaifir sdivit,ies of t.he free amino
‘l’l~c~ opcrntion of the citric acid cycle in:r\- IJCinfcrrcd frown the isolation of rnclioactive gltltamatc~ an(l aspartat,c:. This suppoAtion lw been confirmed by later csperinicnts (26 I in wliicli the specific a&vit> of CO, and information from the tlegrndation of citrate, malate: glutamate, aspnrtatc~, and svrine have shovn thnt the cit,ric acxid cycle is an impoltant clement in tlic osidative reactions of rat skin. LIore Cr40, was produced from gluc~osc~l-Cl4 than from ~IUCOSC-fXY4. However. the ratio c~hnnged during the incubation from 4.7 at 1 hr. to about 2 at 3 and 5 11r. The CIWZ tlata in thcsc csprriments arc) in gcncr:~l :tg~~c~~inontwith the results of Freinkc1 n-itll lrulr~an lwt-mortem skin 1141. In the roac*tion:: of the l?mbdcn-?\lcycrhof pathway and Gtric acicl cycle both the C-t ant1 (‘-6 1)ositions of gluroSc arc coilr-crtetl to Inc~tllpl ~1’Oll~E of pylYwntc :mrt I:LCt:lt~P and :II’O tllcrcufter metabolized identically. Chnri1ctc~ri~tics of the pentose cycle are the 105~ of C-l of glucose as CO, and the diffcrctrt metabolism of C-l and C-6. Frcinlie1 estim:tt,cd the percentages of gluroso mrtabolizcd via the pentose cycle and T-in
3. 4. 5. 6. 7. 8. 9. 10.