MetaTOC stay on top of your field, easily

Impact of ventilation induced lung injury on the structure and function of lamellar bodies

, , , , , , ,

AJP Lung Cellular and Molecular Physiology

Published online on

Abstract

Alterations to the pulmonary surfactant system have been observed consistently in ventilation-induced lung injury including composition changes and impairments in the surface tension reducing ability of the isolated extracellular surfactant. However, there is limited information about the effects of VILI on the intracellular form of surfactant, the lamellar body. It is hypothesized that VILI leads to alterations of lamellar bodies numbers and function. To test this hypothesis, rats were randomized to one of three groups, non-ventilated controls, control ventilation and high tidal volume ventilation (VILI). Following physiological assessment to confirm lung injury, isolated lamellar bodies were tested for surfactant function on a constrained sessile drop surfactometer. A separate cohort of animals was used to fix the lungs followed by examination of lamellar body numbers and morphology using transmission electron microscopy. The results showed an impaired ability of reducing surface tension for the lamellar bodies isolated from the VILI group as compared to the two other groups. The morphological assessment revealed that the number, and the relative area covered by, lamellar bodies was significantly decreased in animals with VILI animals as compared to the other groups. It is concluded that VILI causes significant alterations to lamellar bodies. It is speculated that increased secretion causes a depletion of lamellar bodies that cannot be compensated by de novo synthesis of surfactant in these injured lungs.