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KMID : 0377619620020040393
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Korean Jungang Medical Journal
1962 Volume.2 No. 4 p.393 ~ p.429
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Connective Tissue Structure of the Adrenal Cortex and its Behavior
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Abstract
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Many attempts to investigate the histology and the function of adrenal have been made during recent years. Among them, the success in the extraction of several corticoids and Selye´s general adaptation concept are the most important contributions.
However, on the localization of corticoids in the adrenal cortex and the origin of each layer, the opinions are in dispute. Nicander proposed the subdivision of the adrenal cortex into five different zones (zona glomerulosa, intermediary zone, zona fasciculata, zona reticularis, and juxtamedullary zone).
Concerning the origin of each zone, Gottschau postulated that the cortical cells
which were stored in the zona glomerulosa migrated into and were active in the zona fasciculata and degenerated in the zona reticularis; on the contrary, Tonutti denied any migration of cells within the cortex, and he introduced the theory of two transformation fields of the zona glomerulosa and the zona reticularis, where cortical cells existed in an inactive state, which were transformed into active fasciculata cells when the cortex was stimulated. Starkel and Wegrzynowski reported for the first time the "fetal cortex," and Howard and Mitchell described a peculiar "X-zone" in young mice. It disappeared during puberty-in males and at the first pregnancy in females.
Recently many diverse postulations and reports on the genetical relation of fetal cotex and X--zone to the zona reticularis, and on their behavior to the hormone were published.
In our laboratory, there have been performed investigations, which are related to another unknown adrenal cortical function; that is, the adrenal cortex is the center of the accelerating action of blood coagulation in vivo when the cortex is stimulated by various agents (such as calcium chloride, electric shock, hypertonic saccharide solution, hypoxia and ACTH etc.). And they postulated that the stimulants which caused the shortening of blood coagulation in vivo in normal animals, and which could not shorten the blood clotting time in an adrenalectomized animal, induced severe liberation of fats including cholesterol and phosphor lipid from the adrenal cortex into blood. And the increase of liberated fats induced shortening of blood coagulation time following acceleration of thromboplastin generation. They also confirmed histochemically that the decrease of fats in the adrenal cortex was most prominent in the zona fasciculata, and that such changes were also accompanied with severe regressive changes in the case of most stimulants or with progressive changes only in the case of ACTH administration. With repeated stimulants, the regressive changes extended to the zona reticularis and concomitantly caused a zona glomerulosa broadening which extended beyond its limit into the zona fasciculata. And such finding of the zona glomerulosa was most distinct in hypophysectomized animals. Such broadening of the zona glomerulosa, however, seems to be unable to determine whether it is a emigration or a transformation by ordinary staining methods. Many discrepancies on the origin of each zone and on the possibility of emigration or transformation seem to have resulted from the observations which were done up to date only in the phase of cells and not in the phase of the connective tissue. If the intercellular findings are particular to each zone, and also genetically peculiar to each zone, and are maintained throughout the life even under various stimulants, then many diverse postulations and discrepancies will be solved.
Part 1 ; At first author intended to confirm whether each layer of the adrenal cortex has its own peculiar structure, and also whether its structure is common and uniform in most mammalians. So 4 kinds of normal domestic animals (cows, pigs, dogs and cats) and 4 laboratory animals (mice, rats, rabbits and guinea pigs), 3 heads of each species, were used. Histological study was made using hematoxylin eosin, Van Gieson´s method and the silverimpregnation method, and the following results were obtained:
? The intercellular structure of the adrenal cortex of these all mammalians which were investigated by author was commonly uniform, and characteristic in each layer despite its diverse cellular structure in´ every species.
? The intercellular structure in the juxtameduilary zone was similar to that of the zona fasciculata and the existence of this zone was confirmed by the intercellular structure in each species experimented except in pigs.
? From the view point of the intercellular structure, author agrees to the subdivision of an adrenal cortex into 5 layers which was proposed by Nicander;
Part II ; If,. on the division of each layer in an adrenal cortex, the characteristic .intercellular structure is more proper than the cellular structure, confirmation of the time when the structure is established in an embryonic adrenal will be interesting and may be a criterion to elucidate the genetical relation of each layer in the ,postnatal adrenal, Human fetal adrenals from the third month up to the tenth month were investigated, and following results were obtained:
① The intercellular structure of a provisional cortex is quite the same as that of a zona reticularis of a postfetal cortex, and was performed in moderate differentiation in the third month fetus, and continued to develops gradually until the end of fetal life,
② In the intercellular structure, the differentiation of the permanent cortex into the zona glomerulosa and the zona fasciculata was not evident till the 7th month fetal adrenal.
Part III; As the genetical difference in development of the intercellular structure between the permanent cortex and the provisional cortex became evident, author intended to investigate the regenerating ability of zona glomerulosa cells after enucleation; that is, the possibility of differentiation of cells into following layers, even into the zona reticularis which is genetically different from the zona glomerulosa. Enucleation of the adrenal was done in rats by the Evan´ s method. The results were as follows:
① Within 5 days after enucleation, almost all the residual cortical cells degenerated but the intercellular structure remained partially, which later composed a new irregular intercellular network in connection with regenerated fibers.
②The peculiar intercellular structures corresponding to the zona glomerulosa and the zona fasciculata were-established 5,weeks after operation, nevertheless, that of the zona reticularis was not reformed.
Part IV; Author elucidated the genetical development diffference and. the limit of regenerating ability between the zona glomerulosa and the zona fasciculata, and also the zona reticularis. There are many reports on emigration or transformation into fasciculata cells of glomerulosa cells. Author intended to confirm whether or not a real emigration happens in postnatal life, and, from the view point of the characteristic intercellular structure of each layer, observed the adrenal cortex from rabbits which were treated with calcium chloride, electric shock, nitrogen gas, ACTH and cow serum, and which were hypophysectomizect. The results were as follows:
① in the hypophysectomized rabbits, intercellular fibers of the zona fasciculata disappeared gradually in parallel with the destruction of the same layer, and simultaneously a real broadening of zona glomerulosa into zona fasciculata was confirmed.
② Regressive changes of zona fasciculata from rabbits following repeated calcium chloride injection were accompanied with emigration of glomerulosa cells into the zona fasciculata which later would become fasciculata cell.
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