Adrenal cortex lipid droplets

Indeed, the early histologists characterized cellular and tissue constituents as fully as was possible with the histological methods and the knowledge of chemistry that were available. Around the turn of the century, the lipid droplets in certain cells of the adrenal cortex, testis, ovary, and placenta were shown to be distinguishable from fatty droplets in other tissues. Some of these observations were cited by reviewers in Cowdry s Special Cytology (1932 Rogoff Rasmussen Corner). Recently acquired information makes a re-examination of the older literature appropriate. The following section will consider only the more important work of this early period. 

In the cat s adrenal cortex, Bennett found that yellow phenylhydra-zones and metallic silver both appeared predominantly in the outer portion of the zona fasciculata, the so-called spongy zone. These reactions failed to develop if the sections were previously extracted with acetone or ethyl alcohol at room temperature, indicating that the reactive compounds were readily soluble in such lipid solvents. In this same zone, the cells contained abundant small hpid droplets, as demonstrated with Sudan dyes or osmic acid. 

Direct attempts to demonstrate the ketonic nature of the reactive lipids have been made by Seligman and co-workers (Seligman and Ashbel, 1951, 1952 Ashbel et al., 1951). They reported that a positive hydrazide reaction still occurred in droplets in the adrenal cortex and the testis following the differential blocking of aldehydes by sulfanilic acid or aniline (Oster and Mulinos, 1944). This is particularly significant since Boscott and Mandl (1949) found that aniline effectively blocked all staining with phenylhydrazine. 

Histochemically, positive reactions have been reported with this test in lipid droplets in the ovary (Everett, 1945, 1947 Claesson and Hillarp, 1947a, 1947b Deane and Barker, 1952) in the adrenal cortex (Whitehead, 1942 Vicari, 1943 Nichols, 1948 Yoffey and Baxter, 1949 Deane, 1951) and in the testis (McEnery and Nelson, 1950 Montagna and Hamilton, 1951 Maddock and Nelson, 1952). By model tests, Everett (1947) determined that a positive reaction requires that cholesterol constitute at least 10% of the lipid droplet. Reiner (1953) has obtained comparable results. 

Despite these precautionary remarks, some suggestive data have been adduced by Everett (1947, 1948, 1949), Claesson and Hillarp (1947a, 1947b), and Deane and Barker (1952) to indicate that the Schultz reaction declines or disappears from the lipid droplets in the thecae intemae, interstitial cells, and lutein cells of the ovary at those periods when there is physiological evidence that hormone secretion is rapid, and reaccumulates when secretion subsides. Corresponding data for the adrenal cortex have been presented by Nichols (1948), Yoffey and Baxter (1949), and Cain and Harrison (1950). 

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