Growth Hormone Hyperresponsiveness to Dopaminergic Stimulation in Huntington’s Chorea

The effect of 3 dopamine (DA) mimetic drugs, i.e. bromocriptine (Bro), apomorphine (Apo) and L-3,4-Dihydroxyphenylalanine (L-dopa), was evaluated on plasma growth hormone (GH) levels in 18 patients with Huntington’s chorea (HC). 27 nonobese hospitalized patients were used as controls. Mean baseline GH levels were not altered in patients with HC. Oral administration of Bro (2.5 mg po) or L-dopa (500 mg), or subcutaneous administration of Apo (1.0 mg) resulted in a significantly greater and more prompt (Bro, L-dopa) increase in plasma GH in patients than in controls. These results suggest the presence of an altered dopaminergic regulation of GH secretion inHC.