Uptake, efflux and metabolism of the polyamine putrescine in rabbit lung slices

Saunders, NA, Ilett, KF and Minchin, RF (1987) Uptake, efflux and metabolism of the polyamine putrescine in rabbit lung slices. BBA - Molecular Cell Research, 927 2: 170-176. doi:10.1016/0167-4889(87)90131-5


Author Saunders, NA
Ilett, KF
Minchin, RF
Title Uptake, efflux and metabolism of the polyamine putrescine in rabbit lung slices
Journal name BBA - Molecular Cell Research   Check publisher's open access policy
ISSN 0167-4889
Publication date 1987-02-18
Year available 1987
Sub-type Article (original research)
DOI 10.1016/0167-4889(87)90131-5
Open Access Status Not yet assessed
Volume 927
Issue 2
Start page 170
End page 176
Total pages 7
Place of publication AMSTERDAM
Publisher ELSEVIER SCIENCE BV
Language eng
Subject 1304 Biophysics
1307 Cell Biology
1312 Molecular Biology
Abstract The herbicide paraquat is a selective pulmonary toxin in many mammals, including man, and its pulmonary toxicity has been attributed to selective uptake by a polyamine transport system in lung. In the present study, we investigated the characteristics of this transport process in rabbit lung slices. [14C]Putrescine was accumulated by both saturable and non-saturable processes and the accumulated putrescine was non-effluxable over 60 min. The saturable component was inhibited by spermine and paraquat. Moreover, uptake studies in Na+-deficient medium indicated that the lack of Na+ may selectively enhance uptake via the non-saturable process. The two components also differed in the metabolic fate of accumulated substrate. At 0.6 μM putrescine, where the saturable process predominated, 98% of the 14C in the perchloric acid-soluble fraction of tissue homogenates was present as putrescine, whilst 3% of the accumulated substrate was found in the acid-insoluble fraction. With 500 μM putrescine, where the non-saturable process predominated, 82% of the 14C in the acid-soluble fraction was present as putrescine and 15% of accumulated putrescine was found in the acid-insoluble fraction. The acid-insoluble 14C was localised mainly in the 700 g and 4500 g pellets obtained after homogenising the tissue. We conclude that there are two components to putrescine uptake in rabbit lung slices, both of an apparently irreversible nature. We suggest that the components represent compartmentalisation of putrescine in selective pulmonary cell-types or separate subcellular organelles. The observed metabolism and covalent binding of putrescine appeared to be associated with the non-saturable component only.
Keyword (Rabbit lung)
Polyamine metabolism
Putrescine transport
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Unknown

Document type: Journal Article
Sub-type: Article (original research)
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