PULMONARY UPTAKE OF LIPOSOME-ASSOCIATED ALPHA-TOCOPHEROL FOLLOWING INTRATRACHEAL INSTILLATION IN RATS

Authors
  1. Suntres, Z.E.
  2. Hepworth, S.R.
  3. Shek, P.N.
Corporate Authors
Defence and Civil Inst of Environmental Medicine, Downsview ONT (CAN)
Abstract
The study examined the uptake and subcellular distribution of alpha-tocopherol in the lung following intratracheal instillation of liposome-associated alpha-tocopherol in rats. The liposomal suspension was composed of dipalmitoylphosphatidylcholine (DPPC) and alpha-tocopherol (molar ratio 7:3), labelled with (3H)alpha-tocopherol and (14C) cholersterol. The results of the the present study showed that following intratracheal administration of the liposomal preparation (2mg alpha-tocopherol/animal), the recovery of (3H) alpha-tocopherol in the lung was maximal (87% of initial dose) 1 hr after treatment; thereafter, alpha-tocopherol levels remained relatively high (no less than 73% of initial dose) for the rest of the 72-h experimental period. This treatment effect resulted in approximately 16-fold increase in pulmonary total alpha-tocopherol concentration 72 h post-instillation. No radioactivity was detected in the blood, liver, kidney, pancreas, spleen and heart of animals during the 72-h experimental period. Measurement of radioactivity in the subcellular fractions of the lung tissue showed that (3H) alpha-tocopherol was recovered largely from cytosolic (45%) and nuclear (36%) fractions and to a lesser extent, from microsomal (11%) and mitochondrial (9%) fractions. Chromatographic analysis of the subcellular fractions reavealed that (3H)alpha-tocopherol was co-eluted with 14C-labelled liposomal lipids. TRUNCATED
Report Number
DCIEM-92-P-36 — Reprint
Date of publication
20 May 1992
Number of Pages
7
Reprinted from
J Pharm Pharmacol, vol 45, 1993, p 514-520
DSTKIM No
93-04463
CANDIS No
133337
Format(s):
Hardcopy;Originator's fiche received by DSIS

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