PT  - JOURNAL ARTICLE
AU  - Fabisiak, J P
AU  - Vesell, E S
AU  - Rannels, D E
TI  - Interactions of beta adrenergic antagonists with isolated rat alveolar type II pneumocytes. II. Receptor-independent accumulation of beta adrenergic antagonists and other cationic amphiphilic drugs in lamellar bodies.
DP  - 1987 May 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 728--735
VI  - 241
IP  - 2
4099  - http://jpet.aspetjournals.org/content/241/2/728.short
4100  - http://jpet.aspetjournals.org/content/241/2/728.full
SO  - J Pharmacol Exp Ther1987 May 01; 241
AB  - Accumulation of basic drugs by pulmonary tissue is well known. The cationic amphiphilic nature of many of these compounds suggests that they may be sequestered within an acidic and/or phospholipid-rich compartment. We described previously receptor-independent, concentrative, temperature- and pH-dependent sequestration of the beta adrenergic antagonists [125I]iodocyanopindolol and [125I]iodopindolol by intact rat type II pneumocytes in primary culture. The present study reveals that type II pneumocytes sequester [125I]iodocyanopindolol to an extent greater than other cell types (type II cells greater than polymorphonuclear leukocytes greater than S49) within 80-min incubations. Localization of fluorescence into large granular structures was observed after incubation of type II cells with 9-aminoacridine-propranolol (9-AAP). The distribution of fluorescence coincides with surfactant-containing lamellar bodies (LB) visualized with tannic acid/osmium staining. The large granule localization of 9-AAP fluorescence decreases with time in primary culture in parallel with changes in cell morphology and decreased numbers of LB. Comparison of patterns of fluorescence after incubation with 9-AAP, acridine orange and 9-aminoacridine (all 1 microM) indicates that localization is not a property of the acridine moiety, but requires the propranolol side-chain. Association of 9-AAP fluorescence with LB is inhibited completely by chlorpromazine (10 microM); the same concentration of propranolol or chlorquine produces less extensive, but detectable, inhibition.(ABSTRACT TRUNCATED AT 250 WORDS)