Ultrastructural characteristics of the microcirculatory bed of the human adrenal cortex in prenatal ontogenesis

By means of transmissive electron microscopy the adrenals have been studied in 25 human embryos and fetuses at the age of 6-36 weeks. Certain stages have been revealed in formation of the adrenal cortex microcirculatory bed. In 6-7-week-old embryos (period of diffuse protocapillary bed) endothelial structure and mesenchymal cells, surrounding the adrenal anlage, resemble one another. A distinguished feature of the endothelium is regularly revealed desmosomes and large vacuoles, often found in cytoplasm of endotheliocytes. In 8-12-week-old fetuses (period when the organospecific microcirculatory bed is forming) sinusoid capillaries differentiate in the internal zone of the adrenal cortex; in endothelium fenestrae, "hatches", "locks" are revealed, the capillary basal membrane is formed. During subsequent time of the intrauterine development perfection of the microcirculatory pathways in the adrenals takes place, the arteriolar link of the subcapsular layer including. By the time of birth morphofunctional maturity of the microcirculatory bed in the adrenal cortex is noted.     

Ultrastructural and immunohistochemical studies on the zona-reticularis cells of the adrenal cortex of normal and 3-methylcholanthrene-treated mice

Summary The drug-metabolism activity of adrenocortical cells of normal and 3-methylcholanthrene (MC)-treated ddY mice were examined ultrastructurally and immunohistochemically. Immunoblot analyses performed prior to immunohistochemistry revealed the presence of a protein — possible equivalent to cytochrome P-450 found in the liver microsomes of MC-treated male rats — in the adrenal homogenate of MC-treated female mice. Immunohistochemistry demonstrated the presence of a cytochrome-P-450-like protein in the adrenal-cortical cells (especially in the zona-reticularis cells) of MC-treated female mice; at the same time, a remarkable increase in the amount of SER in these cells was observed by electron microscopy. These findings suggest that cells of the mouse adrenal gland, particularly those of the zona-reticularis, might participate not only in steroid biosynthesis but also in some sort of drug metabolism (detoxication). In addition, there might be a sex-related difference in ddY mice.Supported by grants from the Ministry of Education, Science and Culture, Japan     

Ultrastructural and immunohistochemical studies on the zona-reticularis cells of the adrenal cortex of normal and 3-methylcholanthrene-treated mice

The drug-metabolism activity of adrenocortical cells of normal and 3-methylcholanthrene (MC)-treated ddY mice were examined ultrastructurally and immunohistochemically. Immunoblot analyses performed prior to immunohistochemistry revealed the presence of a protein - possible equivalent to cytochrome P-450 found in the liver microsomes of MC-treated male rats - in the adrenal homogenate of MC-treated female mice. Immunohistochemistry demonstrated the presence of a cytochrome-P-450-like protein in the adrenal-cortical cells (especially in the zona-reticularis cells) of MC-treated female mice; at the same time, a remarkable increase in the amount of SER in these cells was observed by electron microscopy. These findings suggest that cells of the mouse adrenal gland, particularly those of the zona-reticularis, might participate not only in steroid biosynthesis but also in some sort of drug metabolism (detoxication). In addition, there might be a sex-related difference in ddY mice.     

Ultrastructural studies on the blood-testes barrier of the rat.

Typical pinocytic vesicles were visible in electron micrographs in both outer and inner cellular layers of rat boundary tissue. FF technique revealed that they formed characteristic ribbons of foveoli. Foveoles less numerous were present in outer lamina for the most part of the investigated material. So we believe that this phenomenon speaks in favor of myoblastic origin of that layer.     

Ultrastructural demonstration of dehydrogenases in rat cerebral cortex.

Techniques for the ultrastructural demonstration of dehydrogenases in cerebral cortex are described. The best fixation for good fine structural preservation and retention of LDH and NADH-diphorase was obtained by perfusion with a misture of formaldehyde and glutaraldehyde and for SDH by perfusion with formaldehyde. Comparison of incubation conditions showed that consistent results were obtained using enzyme markers NBT and DS-NBT for LDH and NADH-diaphorase: DS-NBT was more satisfactory than NBT and BSPT for SDH. Penetration of incubation media was improved by Triton X-100: DMSO and ultrasonic treatment were less effective. The techniques enabled the first electron cytochemical demonstration of dehydrogenases in different elements of prefixed cerebral cortex. Ultrastructural sites of enzyme activities were localized within cristae and inter-membrane spaces of mitochondria in nerve cell cytoplasm and its processes, oligodendrocytes and astrocytes. Authenticity of the ultrastructural sites was confirmed by four different control experiments.     

Effects of vinblastine and colchicine on the rat adrenal cortex: morphometric and cytochemical studies

The effects of administration of anti-microtubular drugs--vinblastine and colchicine--on the ultrastructure of the zona fasciculata cells of young rat adrenal were studied. Young male rats were injected with vinblastine and sacrificed 2 hr later or with colchicine and sacrificed 3 hr after drug administration. Animals injected with isotonic saline in same experimental conditions served as controls. Ultrastructural alterations provoked by both drugs, vinblastine or colchicine, were identical and were most prominent in the Golgi areas. They appeared enlarged and crowded with round, or slightly elongated light vesicles, acid phosphatase, and osmium negatives. The Golgi dictyosomes, although keeping their normal morphology, were less numerous and presented cisternae which were narrower and shorter than controls. Electron-dense vesicles, round or elongated, and acid phosphatase positive--lysosomes--were observed in great number in the Golgi areas, intermingled with light vesicles. The relative volume of light vesicles and lysosomes of the treated animals was significantly increased when compared with controls, but the relative volume of dictyosomes was significantly decreased. Also the numerical density of light vesicles and lysosomes of the injected rats was significantly increased when compared with controls. These alterations are highly suggestive of the Golgi involvement in the adrenal secretory process.     

Catecholaminergic innervation of the rat adrenal cortex

Summary The zona glomerulosa of the rat adrenal gland is innervated by catecholaminergic nerves. Using histofluorescence techniques, we observed catecholaminergic plexuses surrounding adrenal capsular and subcapsular blood vessels. Individual varicose nerve fibers that branched off these plexuses were distributed among adrenal glomerulosa cells. This innervation was permanently eliminated after neonatal sympathectomy with guanethidine or 6-hydroxydopamine, but was not affected by ligation of the splanchnic nerve or extirpation of the suprarenal ganglion. At the ultrastructural level, axonal varicosities were commonly observed in close proximity to glomerulosa cells and blood vessels. Nerve fibers and varicosities were found to contain small (30–60 nm) clear vesicles as well as large (60–110 nm) and small (30–60 nm) dense-cored vesicles. In tissue fixed for the dichromate reaction with or without pretreatment with the false transmitter 5-hydroxydopamine, many nerve terminals contained numerous small dense-cored vesicles which are thought to contain catecholamines. These results establish the anatomical substrate for the catecholaminergic innervation of the rat adrenal cortex.     

A correlated stereological and functional studies on the long-term effects of ACTH on rat adrenal cortex

The aim of the study was to investigate the effect of prolonged ACTH administration on quantitative structural changes of the rat adrenal cortex and on function of its cells with particular emphasis on correlation of the results of biochemical estimations with stereologic parameters. Daily injections of 20 micrograms ACTH (Synacthen, Depot) for 35 days results in a marked enlargement of the cortex due to an increase in the volume of all the zones. This increase depends upon hypertrophy and hyperplasia of parenchymal cells. At day 21 of experiment the number of parenchymal cells markedly decreased if compared with day 14, the lost of cells being observed mainly in the zona reticularis. Prolonged ACTH treatment only insignificantly changed serum corticosterone concentration and--if calculated per mg of adrenal weight--did not change adrenal corticosterone concentration and 11 beta-hydroxylase activity and decreased corticosterone output by adrenal homogenate. If expressed per adrenocortical cell or per pair of glands, ACTH increased corticosterone concentration and 11 beta-hydroxylase activity while the drop in corticosterone output occurred only at days 28 and 35 of experiment. The striking differences in and among various functional parameters depicting adrenal steroidogenesis show for necessity--in case of long-term experiments leading to hypertrophy or atrophy of the gland--of using coupled stereologic and biochemical techniques which better evaluate the cytophysiological state of adrenocortical cells.