Dopamine receptor expression and function in corticotroph pituitary tumors

摘要: The role of dopamine agonist treatment in corticotroph pituitary tumors is controversial. aim this study was to evaluate D(2) receptor expression 20 and correlate it the vitro effect agonists on ACTH secretion the vivo short-term cabergoline cortisol secretion. D(2) evaluated by receptor-ligand binding, immunohistochemistry, RT-PCR. A 50% or more decrease daily urinary levels was considered a significant clinical response. At binding, specific binding [(125)I]epidepride found 80% cases. At immunohistochemistry, immunostaining 75% of 83.3% cases (D(2long) 40%, D(2short) 20%, both 40%) Significant vitro inhibition 100% D(2)-positive cases, but not D(2)-negative either bromocriptine cabergoline. vivo after 3-month 60%, although normalization 40% All cabergoline-responsive were associated with expression, whereas all noncabergoline-responsive but one expression. In conclusion, functional receptors expressed in approximately tumors. effectiveness normalizing supports its therapeutic use management Cushing's disease.