A. Lespine et al., RETINOL AND RETINYL ESTER CONCENTRATIONS IN RAT-TISSUES DURING TOTAL PARENTERAL-NUTRITION, Journal of nutritional biochemistry, 9(6), 1998, pp. 316-323
We have previously observed that continuous total parenteral nutrition
(TPN) that supplies retinyl palmitate induces a strong decrease of th
e circulating retinol, which is associated with an impaired hepatic pr
oduction of retinol-binding protein. We have investigated the effect o
f 7 days of TPN on the retinal and retinyl ester concentrations in rat
tissues, relative to the vitamin A status [n = 30 for vitamin A-suffi
cient (A(+)) and n = 30 for deficient (A(-))]. Rats were cannulated fo
r intravenous feeding (n = 12 for TPN-A(+), n = 12 for O-A(-)). Retino
l and retinoic acid in serum and retinol and retinyl ester concentrati
ons in liver, kidney, lung, heart, and testis were measured by high pe
rformance liquid chromatography. TPN induced a dramatic decrease in ci
rculating retinol of A(+) rats, whereas retinoic acid concentration in
serum was unchanged. When TPN was given to A- rats, retinol concentra
tion in serum remained low. Lower retinol and retinyl ester concentrat
ions were measured in the livers of TPN rats compared with orally pair
-fed rats, no matter the initial vitamin A status (P < 0.02 for A(+) a
nd P < 0.01 for A(-)). By contrast, in extrahepatic tissues, retinol a
nd retinyl ester concentrations were similar in TPN rats compared with
orally pair-fed rats. Our results indicate that TPN induced a decreas
e of retinol in serum and retinyl esters in liver. However, TPN was ab
le to maintain retinol and retinyl ester concentrations in extrahepati
c tissues of vitamin A-sufficient rats and to restore retinol and reti
nyl ester concentrations in extrahepatic tissues of vitamin A-deficien
t rats, albeit a low circulating retinol. (J. Nutr. Biochem. 9:316-323
, 1998). (C) Elsevier Science Inc. 1998.