Fig. 5

Transmission electron microscopy of lung parenchyma in control (C) animals treated with i.p. saline (Sal, a, b, and c) or ghrelin (Ghr, d, e, and f), as well as elastase-induced emphysema (ELA) mice treated with i.p. saline (g, h, and i) or ghrelin (j, k, and l). Note normal alveolar epithelium (type 2 epithelial cell, P2) and intact alveolar septa (AS) and capillary membrane (Cap) in C-Sal (a-c) and C-Ghr (d-f). Activated macrophages (Mac*) with lysosomes and glycogen accumulation can be visualized in the alveolar space in ELA-Sal (i). ELA-Sal animals show rupture of alveolar septa with loss of capillaries and increased collagen fibre content (in AS) (g and h). After ghrelin therapy, there is visible repair of the capillary (j), proliferation of type 2 epithelial cells (P2) (k), suggesting epithelial repair, as well as activated macrophages with lysosomes and glycogen accumulation (l)