Abstract
Extract: Human term placental lysosomes have been isolated and their quantitative density distribution has been established by biochemical and morphologic analysis. Histologic examination of placental villi after passage through the tissue press reveals minimal contamination due to platelets and leukocytes. Fluorescence microscopy with acridine orange demonstrates lysosomes in the syncytium. Differential centrifugation yields two lysosome populations. One segregates with endoplasmic reticulum, whereas the other is similar to lysosomes isolated from other tissues. The classic lysosomes have a peak density of 1.195 g/ml and are heterogeneous with respect to size and distribution within the density gradient. Acid phosphatase is differently distributed than the other acid hydrolases and is not a suitable marker for placental lysosomes. The enzyme cleaving glucose 6-phosphate is broadly distributed and not necessarily identical with the glucose 6-phosphatase (EC. 3.1.3.9) of other tissues. Peroxisomes are absent from term placenta.
Speculation: Placental lysosomes are considered to play a role in fetal-maternal transport, cellular differentiation, and remodeling. The organelle may be affected by sequential fluxes in steroidal sex hormones. Present knowledge of the characteristics of placental lysosomes and their role in these physiologic processes is limited. Isolation and characterization of lysosomes from placentas of different gestational ages will provide answers to these questions.
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Corash, L., Gross, E. Subcellular Constituents of Human Placenta. I. Isolation and Characterization of Lysosomes from Term Tissue. Pediatr Res 7, 798–811 (1973). https://doi.org/10.1203/00006450-197310000-00003
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DOI: https://doi.org/10.1203/00006450-197310000-00003