Alteration of total body potassium during intravenous feeding without change of body cell mass

0.121 AiTERATION OF TOTAL BODY POTASSIUM DURING INTRAVENOUS FEEDING WITHOUT CHANGE OF BODY CELL MASS. D.J. Almond, R.F.G.J. King, L. Burkinshaw, M.J. McMahon, (Departments of Surge--yand Medical Physics, The General Infirmary, Leeds, U.K.) The

equivalence

nutrition glucose study

spares where

IVN

60%

for

lipid body

There

was

glucose, no

was

Thus, body

40%

mass

of

were

as

Studies

more

sources of

of

total

effectively

energy

body

(I),

using

was TBK

but

the

changes lipid

with

concentration TBK

of

receive TBN

TBK

reverse was

suggest found

that in

a

to measure total body nitrogen is that TBN and TBK may change four patients fed exclusively

non-protein

and

intravenous (TBK)

were

energy

measured

as

glucose

or

simultaneously

as in

a

NAA.

the

associated

to

Changes of

a significant

in

of

and

during

potassium

(NAA) was used this discrepency Twenty refeeding.

randomised

glucose.

significant

changes cell

carbohydrate

unclear.

starvation

weeks

counter no

potassium

and

cell

during two

there

change

group

body

and

whole

fat

remains

neutron activation analysis A possible explanation for

(TBN) (2). independantly by

of

(IVN)

an

group was

of

in

of

group.

(211

+

44

mmol).

9.30

subnormal

intravenous

either

TBK

(0 + 44

increase

which during

TBN

gain

at

+

The

3.43 the

nutrition

In patients receiving : p,O.O I), but there

mmol

gain

mmol/l not

of

in

TBK

(p)O.O5

beginning do

of

the

necessaril

)

in

the

was

glucose

intracellular

study. y imply

changes

of

mass.

1.

Shizgal,

2.

Macfie,

H.M., J.,

Forse,

Smith,

R.A.

R.C.,

J.P.E.N.,

Hill,

G.L.

1981:

5;

391-6.

Gastroenterology,

1981:

80;

103-7.

0.122 COMPARISON OF DIFFERENT TECHNIQUES TO MEASURE PROTEIN SYNTHESIS IN SKELETAL MUSCLE J. Wernerman, K. Magnusson, L. Ekman, A. von der Decken, E. Vinnars (Department of Anesthesiology and Research Laboratory, S:t Erik's Hospital, Vitrum Institute for Human Nutrition, Wenner-Gren Institute for Experimental Biology, Stockholm, Sweden) Determination of protein synthesis (P.S.) in individual organs is important for the understanding of posttraumatic metabolic changes and the evaluation of the effects of nutritional support. Biopsy specimens of 50 mg human muscle are sufficient to measure the concentration and the size distribution of isolated ribosomes. Polyribosome concentration and P.S. capacity are positively correlated. The aim of the study was to compare P.S. activity measured by three different techniques. Methods Rats (n=41) were starved for 3 days followed by 2 days of refeeding. The methods used to study P.S. were: 1. l4C-Phenyalanine was incorporated in protein in vitro. 2. I4C-Leucine was incorporated in isolated ribosomes in a cellfree systembosome size distribution and concentration was determined. Results The incorporation into protein of leucine in a cellfree system and of phenylalanine into protein in the intact muscle both showed 40-60 % decrease on the 3rd day of starvation and a restoration to prestarvation values on the 2nd day of refeeding. The concentration of polyribosomes decreased by 35 % during starvation but did not reach prestarvation values during refeeding. Polyribosomes in percent of total ribosomes decreased by 10 % on the 1st day of starvation and became equal to the origjnal value on the 3rd day of starvation. On the 2nd day of refeeding it exceeded the prestarvation values by 10 %. Concl,usions Ribosome concentration and size distribution show similar trends as the incorporation studies. The relative proportion of ribosomes and their size distribution give valuable information regarding P.S. in skeletal muscle during pathophysiological conditions. 91