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We have studied the effect of chronic noise stress (St) and ACTH administration (Ac) affecting blood pressure and plasma corticosterone levels in male Wistar rats. Both chronic treatments elicited an increase in plasma corticosterone and blood pressure levels. The blood pressure increased from the first week of treatment period in St and Ac rats and remained high 4 weeks after the end of the stress period. However, blood pressure elevation decrease progressively during the first three weeks of post-treatment in ACTH administrated rats. The rise of blood pressure levels was due to the effect of chronic treatment. This was demonstrated by the absence of differences between the two values of blood pressure measurement with and without daily treatment in both St and Ac groups. Increased corticosterone levels decreased rapidly during the post-treatment period in St and Ac rats. The results suggest a possible relationship between the development of hypertension and the Hypothalamus-Hypophysis-adrenal (HHA) axis stimulation in rats.

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Serotonin, gamma-aminobutyric acid and glutamate, which are regulated by glucocorticoids in the central nervous system, are involved in neuroendocrine functions and the development of the brain. The present study investigates the effect of maternal adrenalectomy on the developing serotoninergic, GABAergic and glutamatergic systems. Neurotransmitter levels were measured in four brain areas of both male and female offspring on postnatal days 1, 8, 12 and 22. At postnatal day 1 and 8, the pups of adrenalectomized dams showed higher concentrations of serotonin than controls in all the brain areas studied. Serotonin levels decreased significantly in males at postnatal day 22 in the hippocampus and cortex. During the first 2 weeks of postnatal life, the lack of maternal corticosterone produced an increase in glutamate and a reduction in gamma-aminobutyric acid concentrations, mainly in males. Further, on postnatal day 1, increased serotonin and glutamate levels and lower levels of gamma-aminobutyric were observed in the hypothalamus of male pups born to adrenalectomized dams. The absence of maternal corticosterone affects the pattern of development of the serotoninergic system, especially in the hippocampus and cortex, and particularly in males. A delay in the maturation of the aminoacidergic systems, mainly of the GABAergic system and in males, was also seen. A sexually dimorphic response to the removal of maternal glucocorticoids was seen in terms of neurotransmitter levels, mainly in the hippocampus and hypothalamus.