Acute influence of cigarette smoke on secretion of pulmonary surfactant in rat alveolar type II cells in culture

Abstract

It has been shown, that smoking results in a lower yield of surfactant associated phospholipids in bronchoalveolar lavage (BAL). Indirect evidence suggests impaired secretion. In the present study, we investigated the influence of cigarette smoke on surfactant secretion in cultured rat alveolar type II cells.Smoke exposure was achieved by bubbling the smoke of four cigarettes through Dulbecco's modified Eagle's medium (DMEM) which was adjusted to a reference absorption value of 1.36 at 320 nm. Cells were preincubated with various dilutions of cigarette smoke-treated medium for 30 min, and were then exposed to this medium for 2 h. After this time, secretion of 3 H-choline-labelled phosphatidylcholine (PC) was measured as a marker of surfactant secretion.A 10 fold dilution of cigarette smoke-treated medium inhibited PC secretion stimulated by a combination of terbutaline, adenosine triphosphate and 12-O-tetradecanoylphorbol-13-acetate by over 50%, but did not alter basal secretion. Exposure to less concentrated cigarette smoke-treated medium resulted in less inhibition. Cellular injury was not observed with the concentrations of cigarette smoke-treated medium used in this study. The gas phase of cigarette smoke was not inhibitory at comparable concentrations. Longer exposure to cigarette smoke-treated medium resulted in increased inhibition of PC secretion. The cigarette smoke ingredients, nicotine and benzo[a]pyrene, failed to inhibit PC secretion. Secretion of type II cells exposed to cigarette smoke-treated medium at lower temperatures was not affected. Addition of antioxidants to medium and cells during the preincubation and secretion period did not alter cigarette smoke-treated medium-induced inhibition of stimulated PC secretion.These results demonstrate a direct inhibitory effect of cigarette smoke constituents on surfactant secretion in type II cells. Inhibition is mediated by compounds contained predominantly in the particulate phase of cigarette smoke. Inactivation of the inhibitory effect by lower temperatures suggests involvement of processes such as enzymatic bioactivation or active transport mechanisms.

Enhanced phospholipase B activity and alteration of phospholipids and neutral lipids in Saccharomyces cerevisiae exposed to N-nitrosonornicotine

“…Data are means ± SD, P \ 0.05, # P \ 0.01 and *P \ 0.001 versus control to maintain the normal pulmonary function. Decreased secretion of PC (*50%) was observed in rat alveolar type II cells by cigarette smoke exposure (Wirtz and Schmidt 1996) and similar observation was also reported by Giammona et al (1971). Clinical reports showed decreased surfactant phospholipids in the lavage fluid of smokers (Hohlfeld et al 1997;Finley and Ladman 1972).…”

SASH1, a new potential link between smoking and atherosclerosis

“…However, the vapor phase molecules are lost by this procedure. To solve this issue, another method consists of bubbling the whole cigarette smoke into the culture media or PBS, using a system (usually custom made) of pumps and tubing or simple syringe 96 . This approach has the advantage of containing both compounds from the vapor phase and the particulate phase, however it also comes with a number of drawbacks.…”

Green tea protects human osteoblasts from cigarette smoke-induced injury: possible clinical implication

“…Three cigarettes were blown through 35 ml medium for 15 min with a rate of 1 toke (2 s)per min. Before using the freshly prepared CSM, it was filtered (0.22 μm filter, Sarstedt, Nürnberg, Germany) and its optical density at 320 nm (OD 320 ) was determined using a plate reader (BMG Labtech, Offenburg, Germany) [42].…”