RESUMEN
The brain content of dopamine (DA) and its metabolites [dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA)] were the same in rats with different immobilization times in forced swimming test, while the serotonin (5-HT) concentration was higher in high active (HA, immobilization < 2 min) than low active (LA, immobilization > 5 min) animals. Ethanol (2 g/kg, PO) tended to increase the DA level in the striatum and nucleus accumbens in LA rats and decrease the 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) concentration in HA rats. delta-Sleep-inducing peptide (DSIP) injection reduced the level of 5-HT in the medial prefrontal cortex (MFC) in both groups, did not affect the concentration of DA or DOPAC, but increased HVA in the striatum of HA rats. DSIP injected before ethanol administration augmented the ethanol effects on 5-HT in the MFC and attenuated the action of ethanol on 5-HIAA in the nucleus accumbens. A relationship between the different levels of voluntary alcohol consumption and sensitivity to stress among LA and HA rats and the differences in DA and 5-HT concentrations is suggested. The use of LA and HA rats in developing models for testing of stress-shielding compounds is also described.
Asunto(s)
Monoaminas Biogénicas/metabolismo , Química Encefálica/efectos de los fármacos , Péptido Inductor del Sueño Delta/farmacología , Etanol/farmacología , Ácido 3,4-Dihidroxifenilacético/metabolismo , Consumo de Bebidas Alcohólicas , Animales , Cromatografía Líquida de Alta Presión , Cuerpo Estriado/efectos de los fármacos , Cuerpo Estriado/metabolismo , Dopamina/metabolismo , Electroquímica , Ácido Homovanílico/metabolismo , Masculino , Núcleo Accumbens/efectos de los fármacos , Núcleo Accumbens/metabolismo , Corteza Prefrontal/efectos de los fármacos , Corteza Prefrontal/metabolismo , Ratas , Serotonina/metabolismo , Estrés Psicológico/metabolismoRESUMEN
Delta-sleep-inducing peptide (DSIP) effects on resistance to acute emotional stress induced by electric stimulation of the ventromedial hypothalamus and skin of immobilized rats have been investigated. On the basis of the pattern of cardiovascular reactions, three groups of rats were distinguished: resistant, adapted, and predisposed to the experimental emotional stress. It is shown that DSIP injections increase animals' resistance to acute emotional stress. DSIP also changes the vascular reactivity to episodic emotiogenic stimulations. It is revealed that, after DSIP application, the absence of vascular reactions to emotiogenic ventromedial hypothalamic and electro-skin stimulations significantly increased.