When faced with stress, an organism calls upon several mechanisms to maintain biological
homeostasis. The cardiovascular system is the first to respond usually with an increase in
arterial pressure and tachycardia. Therefore we investigated the central and peripheral
sympathetic responses to acute and chronic starvation in Wistar rats. The noradrenaline (NA)
turnover rate was determined in different catecholaminergic nuclei (A1, A2, A5, A6) as well
as the arterial blood pressure and heart rate modifications. During acute starvation (3 days of
starvation), the NA turnover was increased in the A1 and rostral A2 nuclei as well as in
ventricles and kidneys and decreased in the A6 nucleus. During chronic starvation (4
consecutive cycles of 3 days of starvation plus 1 day of feeding), the NA turnover was
increased in the A5 and caudal A2 nuclei as well as in ventricles and atria and decreased in
the A1 nucleus and kidneys. The arterial blood pressure revealed a gradual decrease during
the first 3 days of fasting but the heart rate was not modified. We conclude that starvation
should be considered as an unusual state of stress because of the absence of locus coeruleus
response (A6 nucleus) despite its well-defined role in stress reactions. One of the
manifestations of these central and peripheral noradrenergic changes is the change in blood
pressure during the starvation-feeding cycles.