Comparison of plasma levels of 11-desoxycortisol (S) , tetrahydro-11-desoxycortisol (THS) and total 11-desoxycorticosteroids (total 11-DCS) , as indices of pituitary-adrenal response to oral metapyrone
Kornel, L.; Ezzeraimi, E.; Economou, P.G.
Materia Medica Polona. Polish Journal of Medicine and Pharmacy 8(2): 108-123
1976
ISSN/ISBN: 0025-5246 PMID: 979350 Document Number: 103413
Methods were developed for the estimation of plasma levels of total 11-desoxycorticosteroids (11-DCS), and levels of 11-desoxycortisol (S) and tetrahydro-11-desoxycortisol (THS), separately. These methods were applied to the determination of pituitary ACTH-reserve, by means of metapyrone test in 350 subjects with a normal pituitary function and in 33 hypopituitary patients. In all of these subjects levels of total 11-DCS were determined (routine method); in 49 of the normal subjects and in 18 of the hypopituitary patients levels of S and THS were also determined. The following results were obtained: in the group of 49 normal subjects, 9 (i.e., 18%) exhibited a response in S levels which was below the lower limit of the range of normal response (false negative response). Levels of THS, following metapyrone administration, were in all normal subjects well within the normal range of response. Out of 420 tests performed in all 350 subjects with a normal pituitary function, in whom total 11-DCS (S + THS) were determined, false negative response was found in 20 (i.e., in 5%). The mean THS/S ratio in normal subjects with the low S response was twice greater (P < 0.01) than that in subjects with an appropriate S response. The false negative S responses to metapyrone in the former subjects was due to a more rapid hepatic metabolic conversion of S to THS. All hypopituitary subjects exhibited significantly lower than normal responses in the plasma levels of both S and THS, and of total 11-DCS. In none of the subjects were plasma levels of cortisol suppressed to 0. The estimation of plasma THS, or total 11-DCS (S + THS), following metapyrone administration, provides a more reliable index of pituitary ACTH-reserve than the estimation of plasma S alone. A concomitant determination of plasma cortisol levels, as indication of the effectiveness of metapyrone in blocking adrenal 11.beta.-hydroxylation, is of value, particularly in the patients with low S and THS responses. The total amount of S present in plasma could be accounted for by the free steroid, whereas 67-100% of THS were conjugated with glucuronic acid.