Amniotic fluid and meconium embolism was experimentally reproduced in adult female rabbits by intravenous infusion of human amniotic fluid and meconium, to clarify histopathologic characteristics of, pulmonary vascular occlusive lesion, in, relation to reduction rate of plasma fibrinogen levels.
1) The principal histopathologic lesions were found mainly in the pulmonary tissue. being summarized as sequences of embolic and/or thrombotic blockage of pulmonary vascular bedsand it was suggested that the severity of those occlusive lesions depended onn the total amount and proportions of the particulate substances contained in fluid. Mild pulmonary edema and alveolar hemorrhages were scattered but accompanied no´ significant inflammatory exudative .reaction.
2) Embolic substance in the vascular beds was composed mainly of epithelial squames and amorphous materials mixed with fat and a few polymorphonuclear cells along the periphery -of the arterioles and capillaries. No mucin or fibrin. thrombi were detected, although bland thrombi plugged rather. larger arterial branches.
3) Infusion.of diluted meconium with or without amniotic fluid resulted in´ iiumediate death within 0 minutes, but in those groups received intra-arterially or intra-. peritoneally, it was not the feature.
4) Mucus content as an important particulate substance of meconium embolism, when present abundant, played a significant role in complete mechanical b..o:kage of vascular beds.
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