ZUR FRAGE DER BIOSYNTHESE VON ALDOSTERON UND 11-DESOXYCORTICOSTERON IN DER NEBENNIERE UND IM ADENOM BEI EINEM PATIENTEN MIT PRIMÄREM ALDOSTERONISMUS

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Abstract
In a 19-year old male patient, suffering from primary aldosteronism, the biosynthesis of 11-deoxycorticosterone and aldosterone was studied in slices of normal and adenomatous adrenal tissue; [4-14C] progesterone and [4-14C] 17α-hydroxyprogesterone were used as substrates. In addition, the urinary excretion of 1 1-deoxycorticosterone, tetrahydro-11-deoxycorticosterone and aldosterone was determined before and after operation. As compared with normal adrenal tissue, a very high activity of the 21-hydroxylase towards progesterone (metabolite: 11-deoxycorticosterone) as well as 17α-hydroxyprogesterone (metabolite: 17α-hydroxy-11-deoxycorticosterone) was found in the adenoma. In contrast, the activity of the 11β-hydroxylase was much less in the adenoma than in the normal adrenal tissue. In the absence of cofactors, only traces of aldosterone were detected in the experiments with slices of the adenoma, whereas a normal rate of production was observed in the experiments with the adrenal slices. The excretion of aldosterone in urine varied between 29.4 and 70.7 μg/24 h before operation; it was unaffected by dietetic measures, thus indicating an autonomy of the tumour. After operation, the concentration of aldosterone in urine fell to normal values (6.1–9.1 μg/24 h). The excretion of free 11-deoxycorticosterone (0.2–2.0 μg/24 h) and of its tetrahydroderivative (31.7–40.4 μg/24 h) was in the normal range before as well as after operation. The increased formation of 11-deoxycorticosterone and the decreased formation of aldosterone in the adenoma under in vitro conditions stand in contrast to the normal excretion of 11-deoxycorticosterone and the increased excretion of aldosterone in urine before operation. This discrepancy may be explained by the deficiency of cofactors in the slices of the adenoma. The results obtained support the view that, in steroid producing organs with high activities, only limited conclusions can be drawn from in vitro experiments to the situation in vivo.

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