Morphogenesis of albino rat lung: An autoradiographic analysis of the embryological origin of the type I and II pulmonary epithelial cells

1970 ◽  
Vol 132 (1) ◽  
pp. 69-87 ◽  
Author(s):  
Karen Hitchcock O'Hare ◽  
Philip L. Townes
1990 ◽  
Vol 38 (2) ◽  
pp. 233-244 ◽  
Author(s):  
D J Taatjes ◽  
L A Barcomb ◽  
K O Leslie ◽  
R B Low

We used post-embedding cytochemical techniques to investigate the lectin binding profiles of rat lung alveolar epithelial cells. Sections from rat lung embedded in the hydrophilic resin Lowicryl K4M were incubated either directly with a lectin-gold complex or with an unlabeled lectin followed by a specific glycoprotein-gold complex. The binding patterns of the five lectins used could be divided into three categories according to their reactivity with alveolar epithelial cells: (a) the Limax flavus lectin and Ricinus communis I lectin bound to both type I and type II cell plasma membranes; (b) the Helix pomatia lectin and Sambucus nigra L. lectin bound to type II but not type I cells; and (c) the Erythrina cristagalli lectin reacted with type I cells but was unreactive with type II cells. The specificity of staining was assessed by control experiments, including pre-absorption of the lectins with various oligosaccharides and enzymatic pre-treatment of sections with highly purified glycosidases to remove specific sugar residues. The results demonstrate that these lectins can be used to distinguish between type I and type II cells and would therefore be useful probes for investigating cell dynamics during lung development and remodeling.


1998 ◽  
Vol 275 (4) ◽  
pp. C1151-C1157 ◽  
Author(s):  
Haruko Funaki ◽  
Tadashi Yamamoto ◽  
Yu Koyama ◽  
Daisuke Kondo ◽  
Eishin Yaoita ◽  
...  

Aquaporin (AQP) 5 gene was recently isolated from salivary gland and identified as a member of the AQP family. The mRNA expression and localization have been examined in several organs. The present study was focused on elucidation of AQP5 expression and localization in the eye, salivary gland, and lung in rat. RNase protection assay confirmed intense expression of AQP5 mRNA in these organs but negligible expression in other organs. To examine the mRNA expression sites in the eye, several portions were microdissected for total RNA isolation. AQP5 mRNA was enriched in cornea but not in other portions (retina, lens, iris/ciliary body, conjunctiva, or sclera). AQP5 was selectively localized on the surface of corneal epithelium in the eye by immunohistochemistry and immunoelectron microscopy using an affinity-purified anti-AQP5 antibody. AQP5 was also localized on apical membranes of acinar cells in the lacrimal gland and on the microvilli protruding into intracellular secretory canaliculi of the serous salivary gland. In the lung, apical membranes of type I pulmonary epithelial cells were also immunostained with the antibody. These findings suggest a role of AQP5 in water transport to prevent dehydration or to secrete watery products in these tissues.


1992 ◽  
Vol 262 (5) ◽  
pp. L582-L589 ◽  
Author(s):  
D. E. Rannels ◽  
S. E. Dunsmore ◽  
R. N. Grove

Both type I and type II pulmonary epithelial cells contact the extracellular matrix (ECM). Type II cell-ECM interactions are bidirectional; they involve matrix-mediated modulation of type II cell differentiation, as well as cellular synthesis and deposition of ECM components. The present experiments examine the kinetics of accumulation of newly synthesized proteins in cell and matrix fractions from primary cultures of type II pneumocytes. Cycloheximide-sensitive incorporation of [3H]leucine into total protein of both the cell and ECM fractions was linear for 24–30 h, when steady-state labeling was reached and maintained to at least day 8. Over this interval, the cells enlarged but did not divide. Newly synthesized proteins recovered in the matrix fraction averaged 1–2% of those in the cells. Relative rates of radiolabeling of matrix proteins peaked at culture day 2 and increased in the absence of serum. In short-pulse studies, initial rates of protein synthesis were equal on culture days 1 and 3; this suggested that the steady-state labeling kinetics above reflected protein turnover. This was supported by rapid loss of radioactivity from the ECM after fresh type II cells were seeded on a prelabeled, cell-free matrix surface. Fresh or conditioned Dulbecco's modified Eagle's medium containing 10% fetal calf serum had little effect on matrix stability. These results demonstrate regulated deposition and turnover of a complex ECM by type II cells and provide a basis for further investigations of factors that control these processes.


1998 ◽  
Vol 274 (4) ◽  
pp. L647-L656 ◽  
Author(s):  
Robin N. N. Han ◽  
Victor K. M. Han ◽  
Shilpa Buch ◽  
Bruce A. Freeman ◽  
Martin Post ◽  
...  

Expression of insulin-like growth factor (IGF) I and its type I receptor is increased in the adult rat lung exposed to 85% O2. We hypothesized that there would be a parallel up- and downregulation of growth-stimulating and growth-inhibiting IGF binding proteins (IGFBPs), respectively. The normal adult rat lung expresses mRNAs for IGFBP-2, -3, -4, -5, and -6 but not for IGFBP-1. O2 exposure for 6 or 14 days reduced IGFBP-3 and -6 and increased IGFBP-4 mRNA abundance. IGFBP-5 mRNA was reduced at 6 days but increased at 14 days. IGFBP-4 mRNA was localized to perivascular and peribronchial interstitial cells and IGFBP-5 mRNA to airway and alveolar epithelial cells. IGFBP-2, -4, and -5 immunolocalized to airway epithelial cells in normal lung and to perivascular exudates after 6 days in 85% O2. IGFBP-2 was diffusely increased throughout the lung tissue only after a 6-day exposure. IGFBP-5 was reduced after a 6-day exposure but was increased and widely distributed after 14 days. IGFBP-4 increased over airway epithelium and subepithelial cells after 6 days and over perivascular interstitial cells after 14 days of 85% O2. These data are consistent with the predicted changes for IGFBPs on O2 exposure except that the generally growth-inhibitory IGFBP-4 was increased at sites of active cell proliferation.


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