Browsing by Author "SANCHEZ, R"

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    INHIBITION OF STRESS-INDUCED HYPERGLYCEMIA BY TAIL PINCHING OR INTRAVENTRICULAR ENKEPHALIN ADMINISTRATION IN THE RAT
    (1988) SANCHEZ, R; VARGAS, L
    The tail pinch (t-p) method added to a basal restraint stress produced inhibition of the stress-induced hyperglycemia, an effect that was neutralized with intrathecal anesthesia but not with intracerebroventricular (i.c.v.) naloxone (50, 100, 1000 ng/100 g) or with intraperitoneal naloxone injections (0.1-0.3 mg/100 g). A similar negative result was obtained with i.c.v. administration of 500 and 1000 ng/100 g of .beta.-endorphin. In contrast, a single i.c.v. injection of 1000 ng/100 g of Met-enkephalin reproduced the t-p inhibitory effect. The latter was not elicited by i.c.v. FK 33824, an enkephalin analogue, a result that supports the specific participation of the .delta.-opioid receptors. The results obtained with central .alpha.-adrenoceptor antagonists and central noradrenergic chemical destruction, or central .alpha.-adrenoceptor agonists, support the production of a reinforcement of the .alpha.-adrenoceptor stress stimulation by the t-p procedure, probably through noradrenaline and enkephalin mediation.