Fasting and hypothalamic catecholamines in goldfish

Hypothalamic catecholamines and their metabolites have been studied after 7 days starvation and starvation plus 1 day refeeding in goldfish Carassius auratus. A reduction of norepinephrine (NE) and dopamine (DA) content (21 and 28%, respectively) together with an increase (53%) of NE turnover, without significant modifications of DA turnover was observed following 7 days starvation. These data indicate that NE and DA are involved in the hypothalamic response to fasting in fish. Different mechanisms can be suggested, that is, an activation of noradrenergic system and a decrease of dopaminergic system by fasting. NE would stimulate food intake, whereas DA would inhibit it.