No abstract

In addition to hypophyseal control, steroid synthesis and secretion in the adrenal cortex is also under direct local neural modulation. We obtained morphological and neurochemical evidence that a substantial proportion of the noradrenergic nerve endings lie in close proximity to zona glomerulosa cells without making synaptic contact, thus providing evidence for a direct local modulatory role of catecholamines in steroid secretion. These noradrenergic neurones, like other noradrenergic neurones in the central nervous system, are able to take up dopamine (DA), convert it partly into noradrenaline (NA) and to release both NA and DA together with the co-transmitter ATP when neuronal activity drives them to do so. These catecholamines and ATP may reach zona glomerulosa cells via diffusion in a paracrine way and modulate the synthesis of aldosterone. The presence of ecto-Ca-ATPases, enzymes that may terminate the effect of ATP, was demonstrated around the nerve profiles indicating that not only ATP but its metabolites (ADP, AMP, adenosine) can also influence the production of aldosterone. These data strongly support the possibility of a paracrine, non-synaptic modulatory role of catecholamines and ATP in the regulation of adrenocortical steroid secretion.

No abstract

The capacity of the adrenal gland of the mouse to form steroids in vitro, using incubation techniques with [4-14C]progesterone, was investigated.Reasons are given for the identification of two oestrogens, 16-oxooestrone and 17-epioestriol and two adrenocorticosteroids, corticosterone and 20\g=a\-hydroxycorticosterone. The presence or absence of the X zone did not appear to influence the relative amounts of oestrogens and adrenocorticosteroids produced. No compounds which could be unequivocally characterized as androgens (C19 steroids) were found.

SUMMARY Cells set about the renal tributaries of the post-cardinal veins of lungfish displayed staining properties similar to those generally characteristic of adrenocortical tissue in tetrapod vertebrates. Furthermore, the reactions of these cells in the lungfish, during aestivation and in the free-living forms, after injections of adrenocorticotrophic hormone, cortisol or hydroxylase inhibitor, metyrapone (Metopirone, Ciba), paralleled those occurring in the adrenal cortex of a variety of animals after equivalent treatment. Tissue, separated from the kidney so as to contain these cells, was capable of converting, in vitro, progesterone to corticosterone whilst control renal tissue had this capacity to only a negligible degree. On these grounds, it is suggested that these cells, in cord-like groups of three to ten, situated by the post-cardinal veins between renal and peri-renal tissue are true adrenocortical cells. The arrangement and nature of these cells are very similar to the adrenocortical tissue of amphibians, particularly adult urodeles and developmental stages of anurans. These findings are discussed in relation to the possible pattern of the evolution of the adrenal gland.