No abstract

Using a monodonab antibody and affmity-puni.tied polyclonal antiserum against a 10 KD protein isolated from rat pulmonary bavage, we have localized the protein within Clara cells by a post-embedment protein A-gold technique. The gold parnides were localized over the secretory granules ofrat Clara cells. Ultrastructural immunobocalization was abolished when the primary antibodies were previously absorbed with punfled 10 KD protein. Other pulmonary cells, including type Literature Cited

The reactivity of rabbit antisera to rat lung secretory proteins with other rodent species was evaluated by immunocytochemistry. Rabbit anti-rat surfactant apoprotein antiserum reacts with the cytoplasm of rat, mouse, and hamster type II pneumocytes and is specific for these cells. Rabbit antiserum to rat Clara cell secretory proteins stains rat, mouse, and hamster Clara cells. Rabbit antisera specific to the two antigenic types of rat Clara cell antigens were also both reactive with rat, mouse, and hamster Clara cells. An antiserum to the non-serum proteins of hamster lung lavage was also prepared and shown to be specifically reactive with hamster Clara cells. The availability of specific reagents for secretory proteins of rodent lungs is expected to facilitate studies of the respective cell types in various pathologic states.

No abstract

Human surfactant was analyzed for proteins associated with the lipids. Surfactant was isolated from lung lavage by the salt gradient centrifugation method, and the soluble proteins binding to the lipids were recovered by extraction with a low pH buffer. Antiserum to this preparation reacted with surfactant apoprotein A and a 7.5-kDa protein. The 7.5-kDa protein was isolated from reduced and alkylated lung lavage pellet by chromatography. The N-terminal amino acid sequence of the protein indicates that it is a novel protein.