Ketoconazole is an effective drug with acceptable side effects. It should be used under close liver enzyme monitoring. Hepatotoxicity is usually mild and resolves after drug withdrawal.
Bilateral inferior petrosal sinus sampling (BIPSS) is the most reliable procedure for distinguishing Cushing's disease from ectopic ACTH secretion. However, it is less reliable at predicting the lateralization of the pituitary corticotroph microadenoma. We sought to determine whether this could be improved by taking into account the pattern of venous drainage and the precise location of the catheters. We retrospectively studied data from 86 patients who underwent BIPSS. Cushing's disease was predicted in 74 patients, of whom 69 underwent transsphenoidal surgery. Surgical cure was obtained in 65 patients, with identification of a corticotroph microadenoma in 58 cases. In 49 patients the location of the microadenoma predicted by the intersinus ACTH gradient could be compared with the pathologist's data. BIPSS accurately predicted the lateralization of the microadenoma in only 57% of these patients. Prediction was improved to 71% when both venograms and catheters were symmetric (35 patients). In this subgroup accuracy was 86% in patients with both catheters in the inferior petrosal sinuses compared with 50% in patients with both catheters in the cavernous sinuses (CS). Two transient sixth nerve palsies occurred during CS catheterization. Our data suggest that BIPSS results are much improved when venous drainage is symmetric. Catheterization of CS did not improve the results and was less safe.
Cushing's syndrome due to ACTH-independent macronodular adrenal hyperplasia (AIMAH) can be associated with abnormal responses of aberrantly expressed adrenocortical receptors. This study aimed to characterize in vitro the pathophysiology of hypercortisolism in a β-blocker-sensitive Cushing's syndrome due to AIMAH. Cortisol secretion profile under aberrant receptors stimulation revealed hyperresponsiveness to salbutamol (β2-adrenoceptor agonist), cisapride (5-HT4 receptor agonist), and vasopressin in AIMAH cultured cells, but not in normal adrenocortical cells. By RT-PCR, AIMAH tissues revealed β2-adrenoceptor overexpression rather than ectopical expression. MC2R expression was similar in both AIMAH and normal adrenocortical tissues. Curiously, cortisol levels of AIMAH cells under basal condition were 15-fold higher than those of control cells and were not responsive to ACTH. Analysis of culture medium from AIMAH cells could detect the presence of ACTH, which was immunohistochemically confirmed. Finally, the present study of AIMAH cells has identified: a) cortisol hyperresponsiveness to catecholamines, 5-HT4 and vasopressin in vitro, in agreement with clinical screening tests; b) abnormal expression of β2-adrenoceptors in some areas of the hyperplastic adrenal tissue; c) autocrine loop of ACTH production. Altogether, the demonstration of aberrant responses to hormonal receptors and autocrine hormone production in the same tissue supports the assumption of multiple molecular alterations in adrenal macronodular hyperplasia. A síndrome de Cushing secundária à hiperplasia adrenal macronodular independente de ACTH (AIMAH) pode estar associada com respostas anômalas a estímulos sobre receptores hormonais expressos de maneira aberrante no córtex adrenal. O objetivo deste trabalho foi caracterizar a fisiopatologia do hipercortisolismo in vitro na sín-drome de Cushing responsiva a β-bloqueadores decorrente de AIMAH. Em cultura de células, a secreção de cortisol apresentou resposta aumentada ao salbutamol (agonista β2-adrenérgico), à cisaprida (agonista de receptor 5-HT4) e à vasopressina, na AIMAH mas não no córtex adrenal normal. O estudo de receptores aberrantes por RT-PCR demonstrou que o gene do receptor β2-adrenérgico estava superexpresso (e não expresso ectopicamente) nos fragmentos da AIMAH quando comparado ao tecido normal. A expressão de MC2R foi semelhante em ambos. Curiosamente, o nível basal de secreção de cortisol pelas células da AIMAH foi 15 vezes superior às células normais, não havendo resposta das células AIMAH ao estímulo com ACTH. A análise do meio de cultura das células AIMAH revelou a presença de ACTH, que foi confirmada por estudo imuno-histoquímico. Em suma, este estudo demonstrou: a) aumento dos níveis de cortisol in vitro em resposta a catecolaminas, 5-HT4 e vasopressina, correspondendo aos resultados dos testes clínicos para pesquisa de receptores aberrantes; b) expressão anormal de receptores β2-adrenérgicos em algumas áreas de hiperplasia; c) produção autócrina de ACTH. Estes resultado...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.