EphR/ephrin signalling in the rat adrenal cortex. To demonstrate the possibility of specific EphR/ephrin involvement, the tissues were taken from control animals, and from animals subjected to treatments known to have specific actions on adrenal cell
Caroline H Brennan, Alexandra Chittka, Stewart Barker and Gavin P Vinson
Sinead N Kelly, T Joseph McKenna and Leonie S Young
years studies have shown that the transcription factor SF-1 participates in the expression of all steroidogenic enzymes in the adrenal cortex ( Leers-Sucheta et al. 1997 , Hu et al. 2001 a , Bassett et al. 2002 , Sewer & Waterman 2002 ). We have
A. T. COWIE and S. C. WATSON
The hormones of the adrenal cortex play an important role in lactogenesis in several species and adrenocorticotrophin (ACTH) is generally regarded as an essential component of the lactogenic complex of the anterior pituitary (see reviews by Folley, 1952, 1956, 1961; Cowie, 1966). The observations that cortisol acetate or ACTH will induce lactation in the rabbit whose mammary glands are suitably developed (Talwalker, Nicoll & Meites, 1961; Chadwick & Folley, 1962) would appear to agree with this concept of the important role of the adrenal cortex in lactogenesis in this species. Recently, however, Kilpatrick, Armstrong & Greep (1964) have reported that prolactin alone will induce a lactogenic response in the hypophysectomized pseudopregnant rabbit; that is, in circumstances when the level of corticosteroids in the body must be low. It is therefore of interest to test whether prolactin is lactogenic in the rabbit in the absence of the adrenal glands.
Weiye Wang, Lishan Wang, Akira Endoh, Geoffrey Hummelke, Christina L Hawks and Peter J Hornsby
Introduction In the human adrenal cortex the zona reticularis (ZR) is biochemically and functionally distinct from the zona fasciculata (ZF; Hornsby 1995 ). The most significant difference is the level of 3β
I. E. BUSH and K. A. FERGUSON
Adrenal venous blood was collected from six anaesthetized sheep, of which two had been previously hypophysectomized. The blood was extracted and analysed for adrenocortical steroids by paper chromatography. In each case the predominant secretory product found in the extracts was 17α-hydroxycorticosterone. Small amounts of corticosterone and a substance tentatively identified as 11β-hydroxyandrost-4-ene-3,17-dione were also found in all the extracts. Only traces of other reducing steroids or αβ-unsaturated ketosteroids were found: their irregular appearance makes it likely that they were artifacts. It seems unlikely that the secretion of the adrenal cortex in vivo is as complex as the mixture of products released by the perfused beef adrenals in the experiments of Hechter, Zaffaroni, Jacobsen, Levy, Jeanloz, Schenker & Pincus .
The reported actions of cortical steroids, or whole adrenal extracts, when injected into mammals or added to isolated tissues have become so numerous that it has become essential to find out by direct experiment what the adrenal cortex actually secretes into the blood in various conditions. In the absence of direct knowledge of the nature of the cortical secretion, various theories of adrenocortical function have been proposed from time to time [e.g. Sayers, 1950], but recent work has cast considerable doubt upon them. All such theories postulate that the adrenal cortex secretes one or more steroid substances at particular rates in various physiological conditions, and it is necessary to find out whether this is the case or not.
This paper describes experiments on six sheep in which adrenal venous blood was collected and analysed by paper chromatography [Bush, 1953] in order to determine the rate and type of secretion in this species.
I. CHESTER JONES and C. C. ROBY
Male adult mice, 80 days after hypophysectomy, show approximately the same pattern of sodium and potassium intake and sodium, potassium and water output as normal mice. The healthy remnant of adrenal cortex left after the operation is thought to be responsible for the day-to-day competence of the hypophysectomized animal in salt-electrolyte metabolism. The histology of the cortex is described and it is shown that, with the injection of ACTH, a cortex of normal appearance can be regenerated from the persistent zona glomerulosa of the long-term hypophysectomized mouse.
M. M. FERGUSON, J. B. GLEN and D. K. MASON
Cortisol utilization by salivary glands, kidneys and adrenals of various mammals has been compared by using a standard histochemical technique for the demonstration of hydroxysteroid dehydrogenases. 11β-Hydroxysteroid dehydrogenase activity was localized in salivary gland ducts, renal collecting and convoluted tubules and in the adrenal cortex of some species. There was no obvious relationship between the levels of enzyme activity in the salivary glands, kidneys and adrenals. Neither was the presence of 11β-hydroxysteroid dehydrogenase in salivary glands particularly associated with mucous or serous secretion, nor were sex differences in levels of activity evident.
D. KADIOGLU and R. G. HARRISON
During an ultrastructural study of the rat adrenal cortex (Kadioglu & Harrison, 1971) the mitochondria in both normal and experimentally treated rats showed a variable appearance. It was decided to examine further the ultrastructure of adrenal cortical mitochondria in normal rats. Fifty-three adult inbred Wistar rats (136–348 g) were examined. Sliced pieces of adrenal cortices were fixed in 3% glutaraldehyde in 0·1 m-sodium cacodylate buffer and embedded in Araldite, sectioned, stained with lead citrate, and examined with an Hitachi HS 7S electron microscope.
Several different fine structural characteristics were found in the mitochondria of the zona fasciculata in both sexes regardless of age and body weight. The diameters varied from 1·3 × 0·8 μm to 8·4 × 6·2 μm. Although the shape changed from cell to cell they were generally oval or nearly round. The polylaminar membranous internum contained several layers of concentric membranes around a core, or sometimes a double
M. M. Ho and G. P. Vinson
It is now known that in the rat there are two distinct species of cytochrome P45011β/18, namely aldosterone synthase and 11β-hydroxylase. Whereas aldosterone synthase is located exclusively in the zona glomerulosa, the zonal distribution and site of production of 11 β-hydroxylase is not entirely clear. In the present study we examined the zonal expression of 11β-hydroxylase mRNA in adrenals from control rats and animals subjected to ACTH treatment and dietary sodium restriction using a non-isotopic in-situ hybridization technique. The results were compared with those obtained using an inner zone specific antigenic (IZAg) marker to give unequivocal identification of the adrenocortical cell types.
11 β-Hydroxylase mRNA was clearly shown to be expressed in the inner zones of the control rat adrenal cortex, and none was detected in the zona glomerulosa and medulla. The message was more abundant in the outer zona fasciculata. A similar pattern of distribution of 11β-hydroxylase mRNA was observed in adrenals from rats subjected to dietary sodium restriction, although the width of the negatively staining layer of zona glomerulosa was significantly increased. In rats treated with 100 μg ACTH for 1 day, the number of cells expressing 11β-hydroxylase mRNA was increased, especially in the zona reticularis. With continued ACTH treatment, 11β-hydroxylase mRNA was found in the region of the zona glomerulosa, and after 3 and 5 days of ACTH treatment cells expressing 11β-hydroxylase mRNA extended to the connective tissue capsule. At this time there was a significant reduction in the total expression of the message compared with the controls.
These results suggest that the presence of 11β-hydroxylase in the zona glomerulosa cells is not essential for the late pathway for aldosterone biosynthesis from deoxycorticosterone. Like IZAg, the distribution of 11β-hydroxylase mRNA after prolonged ACTH treatment provides further evidence to support the hypothesis that ACTH increases the conversion of zona glomerulosa to zona fasciculata-like cells.
Journal of Endocrinology (1993) 139, 301–306
EVA BRUMMEL, I. D. K. HALKERSTON and M. REISS
The action of different steroid hormones on the oxygen consumption of adrenal cortex slices in vitro was investigated.
Deoxycorticosterone (DOC), testosterone and dehydroisoandrosterone, and 17-hydroxycorticosterone, were found to stimulate the oxygen uptake rate, while cortisone, progesterone, pregnenolone, androsterone and cholesterol were inactive.
Pretreatment of the slices with DOC, testosterone or ACTH inhibited the action of ACTH or DOC added subsequently.
The significance of the direct action of different steroid hormones on the energy metabolism of the adrenal cortex is discussed.