Am J Physiol. 1996 Jul;271(1 Pt 1):L178-85.

Distribution of alveolar type II cells in neonatal and adult rat lung revealed by RT-PCR in situ.

Mensah EA, Kumar NM, Nielsen L, Lwebuga-Mukasa JS.

Department of Internal Medicine, State University of New York Buffalo School of Medicine and Biomedical Sciences, Buffalo General Hospital 14203, USA.

Type II pneumocytes in newborn lungs are more uniformly distributed, whereas in adult lungs they are located at alveolar corners. We used morphometry and reverse transcription-polymerase chain reaction in situ hybridization of surfactant protein C mRNA to determine the patterns of type II cell distribution in random lung sections from Sprague-Dawley rats at various neonatal stages and adults. There was a progressive increase in the percentage of type II cells at alveolar corners from 30% at 1 day to 51, 62, 78, and 81% at 3, 5, and 7 days old and adult rats, respectively. There were statistically significant differences (P < 0.001) in the localization of type II cells from the nearest alveolar corner in the 1-day-old compared with 7-day-old and adult rat lungs. These results show that rat type II cells localize to the alveolar corners within the first 7 days postnatally and provide a system for study of factors that regulate alveolar epithelial cell distribution.

PMID: 8760149 [PubMed - indexed for MEDLINE]