Mitochondrial lamellated bodies and surfactant depots in the Type II cells of the lung compared by bimetallic staining and X-ray analysis.

After heavy dosages of sensory irritants osmiophilic whorls (mitochondrial lamellated bodies) are found in the mitochondria of the Type II cells of the lung. To obtain evidence of their nature, the lead/osmium (Pb/Os) ratio in these and other bodies after bimetallic staining was studied by electron probe X-ray analysis during transmission electron microscopy. To allow for inter-specimen variation the Pb/Os ratio was divided by the Pb/Os ratio for chromatin in the same cell, to give a "relative ratio".

Maturity of fetal lungs tested by production of stable microbubbles in amniotic fluid.

Lung surfactant in amniotic fluid, and hence the maturity of the fetal lungs, can be assessed by observation of stable microbubbles (less than 15 micron diameter). Bubbles are formed by agitation with a Pasteur pipette and examined in hanging drops under the 10 x power of a microscope. Either after a count of bubbles, or after a general survey of hanging drops, the fluid is given a stable microbubble rating.

Postmortem changes in the surpellic activity of lung surfactant.

The surpellic activity of lung surfactant in mouse lungs stored in the cadaver persists for times much longer than those after which gross morphological changes at electron microscope level have been recorded.

The relation between surface tension and area in the alveolar lining film.

1. The properties of the rat alveolar lining film have been studied by observing the behaviour in a hanging drop, under reduced or increased ambient pressure, of bubbles derived from the lung.2.

The development of the lung and its surfactant in the foal and in other species.

The development of the lung from the glandular through the canalicular to the alveolar stages in the horse fetus is described. Traces of surfactant and occasional lamellated osmiophilic bodies representing intracellular surfactant were found at 150 days of gestation, some 40 to 60 days before the transition to the canalicular stage. During this transition some of the cuboidal cells of the glandular rosettes are transformed into cells of Types I and II, but the surfactant is not fully developed until 300 days or, in some foals, until after delivery.

Post-mortem changes at electron microscope level in the type II cells of the lung.

In the type II cells of the lungs of mice, left in the cadaver after death, no post-mortem changes at electron microscope level have been found after 30 minutes. At 1 hour cytoplasmic vesicles have appeared and the microvilli have altered. Vesiculation and nuclear contrast then increase, and after 8 hours at 25° most of the cell is occupied by large vesicles and the cell boundary is disrupted.

Lung surfactant and organelles after an exposure to dibenzoxazepine (CR).

Rats were exposed to a heavy dosage of the sensory irritant dibenz (b.f.)-1,4 oxazepine (CR).