[Patients with Parkinson disease: functional analysis of dopamine receptors by bromocriptine- thyrotropin-releasing hormone test].
The bromocriptine-TRH test was performed in 11 patients with advanced Parkinson's disease and in 10 control subjects. Seven patients were receiving treatment with Levo-DOPA, which was discontinued 12 h prior to the test. Basal prolactin levels were 5.88 ng/ml in treated and 18.22 ng/ml in untreated patients as compared to 9.68 mg/ml in controls. Bromocriptine induced a similar reduction of about 60% in prolactin levels in all groups (3.28, 11.5 and 5.95 ng/ml, respectively). After TRH, prolactin levels increased to 13.8 ng/ml in controls and 15.2 ng/ml in patients treated with levo-DOPA. Untreated patients remained with prolactin below basal levels (11.6 ng/ml). We postulate that low basal levels of prolactin in patients treated with levo-DOPA reveal a residual suppressing effect of the drug. The sharp increase after TRH is related to a significant dopaminergic hypofunction as evidenced by clinical findings. A high sensitivity of dopaminergic receptors in the anterior hypofisis is suggested as an explanation for the findings of the test in the untreated patients.
Díaz
F
F
Departamento de Medicina, Facultad de Medicina, Universidad de Chile, Santiago.
Liberman
C
C
Chariá
P
P
D000704:Analysis of Variance; D001971:Bromocriptine; D005260:Female; D006801:Humans; D007030:Hypothalamo-Hypophyseal System / Q000187:drug effects / Q000503:physiopathology; D007980:Levodopa / Q000627:therapeutic use; D008297:Male; D010300:Parkinson Disease / Q000097:blood / Q000188:drug therapy / Q000503:physiopathology*; D011388:Prolactin / Q000097:blood; D011954:Receptors, Dopamine / Q000502:physiology*; D013973:Thyrotropin-Releasing Hormone
D011954:Receptors, Dopamine; D001971:Bromocriptine; D007980:Levodopa; D013973:Thyrotropin-Releasing Hormone; D011388:Prolactin
Pacientes con enfermedad de Parkinson: analisis functional de los receptores dopaminérgicos mediante la prueba de hormona liberadora de tirotrofina-bromocriptina.