Abstract
Stress is an organism's condition in response to exposure to adverse environmental situations, involving essential adaptive responses for survival. The activation of the hypothalamus adrenal-axis, autonomic nervous system and brain structures (eg.: brainstem and amygdala), have an important role in stress, and consequently also in the related pathophysiological process. Oxytocin can be a possible treatment for disorders related to aversive situations, by modulating negative responses to stress. Thus, the aim of the present project is to evaluate cardiovascular, behavioral, endocrine and morphofunctional changes in animals exposed to acute restraint stress (RS) and its relation to the oxytocinergic pathway. Adult Wistar rats (240-260 g) will be used, and will be submitted to the RS model for 180 minutes. The participation of oxytocin in RS-evoked responses will be studied obserserving the effects of the treatment with the oxytocinergic receptor antagonist L-368,899 (3, 6 and 12 mg / kg i.p.). The mean arterial pressure, heart rate and spontaneous baroreflex sensitivity will be recorded. Twenty-four hours after the RS it will begin the behavioral evaluation on the open field test and the elevated plus maze. After each recording session, and behavioral test, it will be collected biological samples for plasma dosage of corticosterone, vasopressin and oxytocin, serum creatinine, urea, aminotransferases and creatine kinase. We also will proceed to morphological evaluation of possible alteration induced in the heart, liver, kidneys, stomach, thymus and adrenals.
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