The Fibroblast of Human Lung Alveolar Structures: A Differentiated Cell with a Major Role in Lung Structure and Function

This chapter describes the importance of the fibroblast of the human lung-alveolar structures. The postnatal lung is a complex organ with function to mediate the exchange of oxygen and carbon dioxide between the atmosphere and the blood. The lung brings air and blood into close proximity in structures termed “alveoli.” In the adult human lung, alveoli are comprised of four major cell types. The fibroblast significantly influences alveolar structure and function through its major role in maintaining the interstitial connective tissue. Morphological studies have demonstrated that human fibroblasts are also capable of ingesting collagen fibrils and thus use phagocytotic mechanisms to modulate the connective tissue matrix. Lungs were obtained from human fetuses following abortion and stored briefly in a sterile culture medium until processing could be initiated. After becoming confluent, pulmonary fibroblasts in the tissue culture measure up to 100 μpm in length and 10 pm in maximal width. The chromatin is evenly distributed with only minimal margination.