Effects of the chronic treatment with L-3,4-dihydroxyphenylalanine (L-Dopa) on the Neuroendocrine Stress Response

ORILLO, SANTIAGO JORDI; IMSEN, MERCEDES; LIZARRAGA, ALFONSINA; ROMERO, ANA CLARA; DE FINO, FERNANDA; PEÑA, MILAGROS; ABELEDO MACHADO, A I; ZÁRATE, SANDRA; FERRARIS, JIMENA; DÍAZ-TORGA, G; PISERA, DANIEL

Congreso; Reunión Anual SAIC - SAFE - SAB - SAP; 2019

Stress evokes a complex response mediated by two systems: the Hypothalamus- Pituitary-Adrenal (HPA) axis and the Sympathetic-Adreno-Medullar (SAM) axis. Glucocorticoids and catecholamines secreted from the adrenal glands and sympathetic nerves are the main hormone effectors of the physiological adaptations observed during stress. Moreover, prolactin (PRL) is another pituitary hormone secreted under stressful stimuli. Catecholamines are synthesized from the hydroxylated precursor L-Dopa. This agent is also used with therapeutic purposes,e.g. in Parkinson?s disease. In the present research, we studied the effects of L- Dopa on the response to a stressor. Adult male Wistar rats (300 g) were chronically treated (24 days) with LEBOCAR (L-Dopa (75 mg/day) - Carbidopa (7.5 mg/day)) orally in drinking water and stressed by immobilization during the last 9 days of treatment. We first explored the activity of the SAM axis. Circulating noradrenaline increased in rats treated with LEBOCAR (p