This experiment was carried out to investigate the inhibitory effects of glycyrrhizin and its aglycon, glycyrrhetinic acid, on the metabolism of cortisol and prednisolone in vivo and in vitro. The effects of glycyrrhetinic acid on the metabolism of cortisol were examined in vitro using rat and bovine liver homogenate. Glycyrrhetinic acid inhibits both hepatic delta 4-5-reductase and 11 beta-hydroxysteroid dehydrogenase in a dose-dependent manner, resulting in the decrease of conversion of cortisol to cortisone, dihydrocortisol and tetrahydrocortisol in rats. The concentrations of glycyrrhetinic acid inducing 50% inhibition of rat liver delta 4-5-reductase and 11 beta-hydroxysteroid dehydrogenase were 2.5 x 10(-6) M and 8.5 x 10(-6) M, respectively. Glycyrrhetinic acid also inhibits bovine liver 11 beta-hydroxysteroid dehydrogenase and 20-hydroxysteroid dehydrogenase in a dose-dependent manner, resulting in the decrease of conversion of cortisol to dihydrocortisol and prednisolone to 20-dihydroprednisolone. The concentrations of this drug inducing 50% inhibition of 11 beta-hydroxysteroid dehydrogenase and 20-hydroxysteroid dehydrogenase were 8.2 x 10(-6) M and 6.5 x 10(-6) M, respectively. This is the first report which demonstrates the marked inhibitory effects of glycyrrhetinic acid on 11 beta-hydroxysteroid dehydrogenase and 20-hydroxysteroid dehydrogenase in vitro. The effects of glycyrrhizin on the rate of metabolism of cortisol as well as prednisolone were studied in 23 patients with or without adrenal insufficiency. Glycyrrhizin had no effect on diurnal rhythm of plasma cortisol in 7 control subjects with normal pituitary adrenal axis, whereas glycyrrhizin significantly increased the half-time (T 1/2) and area under the curve (AUC) for plasma cortisol in 4 patients with adrenocortical insufficiency taking oral cortisol. Glycyrrhizin also increased T 1/2 and AUC for plasma prednisolone in 12 patients taking an oral prednisolone for at least 3 months. These results indicate that the suppression of hepatic delta 4-5-reductase, 11 beta-hydroxysteroid dehydrogenase and 20-hydroxysteroid dehydrogenase by glycyrrhizin and glycyrrhetinic acid may delay the clearance of cortisol and prednisolone and prolong the biological half-life of cortisol or prednisolone.
Adrenal tumors showing no clinical manifestations (incidentaloma) are frequently encountered during imaging analysis upon routine examinations. These tumors are sometimes associated with hypertension and/or diabetes mellitus (DM). We have examined six cases of incidentalomas with these symptoms in this study. All patients underwent endocrinological evaluation by measuring plasma cortisol and aldosterone levels to assess adrenocortical function. The levels of urinary 17-hydroxysteroids, 17-ketosteroids and catecholamines were also measured. Imaging analysis were performed by using 131I-adosterol scintigraphy, computed tomography and magnetic resonance imaging. Whereas one case was diagnosed as having an adrenal adenoma without the examination of a surgical specimen, other cases underwent surgical removal of the tumor, and final diagnoses were made by pathohistological examination of the tumors. Three cases were diagnosed as having adrenocortical adenomas (one was functioning and others were non-functioning) and one case was diagnosed as having a functional adrenocortical carcinoma. Adenomas were found to produce either non-functional steroids or a small amount of functional steroid hormones. The adenoma patients all suffered hypertension, whereas one of the adenoma patients and the carcinoma patient showed signs of DM. By contrast, of the six cases, one case was diagnosed as having an adrenal cyst, and one case was diagnosed with myelolipoma. Although these two cases suffered DM and hypertension, respectively, it seemed to be unlikely that these clinical symptoms were caused by the adrenal disease. Thus, the present analysis of the six incidentaloma patients suggests that once an adrenal incidentaloma patient with hypertension and/or DM is found, both endocrinological and imaging examinations are necessary to determine the indication of surgical treatment. This analysis supports the present consensus that non-functional adenomas whose sizes are 3cm or less and whose sizes do not change at any reevaluation period, as well as adrenal cysts and myelolipoma should not be surgically removed.
O,p'-DDD has a cytotoxic action and inhibits the cholesterol side chain cleavage enzyme, 11 beta-hydroxylase, 3 beta-hydroxysteroid dehydrogenase coupled with delta 5 to 4 isomerase and 21-hydroxylase of the adrenal cells. However, the effects of o,p'-DDD on gonadal steroidogenesis are still unknown. In the present study, the effects of o,p'-DDD on Plasma cortisol, pregnenolone, 17 alpha-hydroxypregnenolone (17-OH-pregnenolone), progesterone, 17 alpha-hydroxyprogesterone (17-OH-progesterone), 11-deoxycorticosterone (DOC), corticosterone, dehydroepiandrosterone (DHEA), delta 4-androstenedione (androstenedione), estradiol, and LH and FSH were investigated in 3 patients with Cushing's disease before and after the administration of o,p'-DDD. The results are presented here. In Case 1 (18 yr old female) who had had secondary amenorrhea for 2 years, the plasma levels of cortisol, pregnenolone, 17-OH-pregnenolone, DHEA, androstenedione, testosterone, estradiol and corticosterone were elevated. The basal levels of plasma LH and FSH and the responses of both gonadotropins were lower than those of women with eumenorrhea. The plasma levels of progesterone, DHEA and testosterone decreased to normal 2 months after the beginning of the administration of o,p'-DDD. She restored menstrual cycles ranging from 40 to 50 days 3 months after the administration of o,p'-DDD, but with anovulatory bleeding. She showed a biphasic body temperature pattern with plasma progesterone and estradiol levels indicating corpus luteum formation 11 months after the start of the treatment, when plasma cortisol as well as progesterone and androgen were reduced to normal. The basal levels of FSH and LH and responses of these gonadotropins were slightly improved at that time. The plasma levels of cortisol, DHEA and androstenedione were high in Case 2 (38 yr old male) and Case 3 (45 yr old male), whereas plasma testosterone level was normal in Case 2 and low in Case 3. The plasma levels of these 3 steroids were normalized 28 days after the beginning of the o,p'-DDD administration. These results suggest that o,p'-DDD does not interfere with gonadal steroidogenesis in Cushing's disease.
We report a 54-year old man diagnosed as idiopathic hyperaldosteronism (IHA) at least 12 years after the onset. At the age of 42, he showed hypertension (162/100mmHg), hypokalemia, metabolic alkalosis, low plasma renin activity (PRA) and normal plasma aldosterone concentration (PAC) in a supine posture. Both PRA and PAC were elevated after a 2-hour ambulation following furosemide (60mg) injection. Since the accumulation of radioactivity following 131I-aldosterol injection with combined administration of dexamethasone was equally detected in both adrenal areas, he was diagnosed as low-renin essential hypertension (LREH). Blood pressure (BP) decreased to the normal range after treatment with nifedipine (40mg/day). At the age of 47, however, BP was hypertensive (164/106mmHg) serum potassium (K) level was normal. Although PAC was normal in a supine posture, it increased after a 2-hour ambulation following furosemide (60mg) injection. PRA after the stimulation was still suppressed despite the increase in PAC. At the age of 54, BP was 172/94mmHg. Serum K level was 3.4mEq/L. PRA was suppressed below 0.1 ng/ml/hr, while PAC was above the normal range (170pg/ml) in a supine posture. Serum cortisol and urinary excretion of 17-OHCS and 17-KS were within normal limits. PRA was still suppressed below 0.1 ng/ml/hr after a 2-hour ambulation following furosemide (60mg) injection, but PAC was markedly increased (330pg/ml). There was a diurnal rhythm of aldosterone, which was parallel to that of ACTH.(ABSTRACT TRUNCATED AT 250 WORDS)
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