Transient appearance of a provocative growth hormone response to L-dopa following incomplete adenomectomy in an acromegalic patient.
A 33-year female patient with active acromegaly and hyperthyroidism was examined before and after incomplete removal of a pituitary adenoma. Before adenomectomy the mean basal plasma GH level was 786+/-189 ng/ml. After surgery this value decreased to 251+/-22 ng/ml. Before surgery L-dopa decreased the plasma GH levels, but after adenomectomy normal GH responses were transiently observed to L-dopa. At 10 months after incomplete surgery the GH response to L-dopa became abnormal again despite a lower GH concentration. These findings suggest that the abnormal GH response to L-dopa may be due to a short-loop negative feedback system which was reset by an elevated GH level.
D000172:Acromegaly / Q000150:complications / Q000378:metabolism*; D000236:Adenoma / Q000150:complications / Q000601:surgery*; D000328:Adult; D005260:Female; D013006:Growth Hormone / Q000097:blood*; D006801:Humans; D007980:Levodopa; D010911:Pituitary Neoplasms / Q000150:complications / Q000601:surgery*
D007980:Levodopa; D013006:Growth Hormone