Browsing by Author "BUSTOS, E"

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    CHOLINERGIC TRANSMISSION IN VAS-DEFERENS
    (1983) BUSTOS, E; MIRANDA, H; PAEILE, C
    Prazosin, haloperidol, propranolol or timolol had no effect on the electrically evoked muscular twitch. Atropine was able to antagonize competitively acetylcholine (pA2 = 9.29 .+-. 0.30). The muscular twitch of the Octodon degus vas deferens was only partially abolished by atropine (53.2 .+-. 0.72). The present results can be interpreted assuming that the O. degus vas deferens has one component muscarinic in its innervation.
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    METAMORPHOSIS OF LABORATORY-REARED LARVAE OF CONCHOLEPAS-CONCHOLEPAS (MOLLUSCA, GASTROPODA)
    (1994) CAMPOS, EO; PINTO, A; BUSTOS, E; RODRIGUEZ, SR; INESTROSA, NC
    Metamorphosis of laboratory-reared larvae of the gastropod Concholepas concholepas was observed under the influence of K+ ions. After 64 h of incubation at 10 degrees C, 58% of larvae metamorphosed in response to 20 mM K+ final concentration in seawater, 11 mM above ambient. No effect was observed at 15 mM K+. Likewise, larvae were unable to survive when exposed to 25 mM K+. Metamorphosed individuals of C. concholepas migrated to the water-air interface within 28 h of their metamorphosis. This study reports the first successful experiment on the induction of metamorphosis in laboratory-reared larvae of C. concholepas. The advantages of mass production of larvae with metamorphic capacity of this economically important resource, related to its eventual culture on a pilot scale are discussed.
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    NATURAL-RESISTANCE TO EFFECTS OF MORPHINE IN OCTODON-DEGUS A SOUTH-AMERICAN RODENT
    (1984) PAEILE, C; CONTRERAS, S; MIRANDA, H; VILLANUEVA, L; BUSTOS, E
    O. degus, a South American caviomorph, presents a natural resistance to some effects of morphine. None of the doses of morphine (i.v.) employed produced a significant modification of respiration rate. The administration of morphine leu-enkephalin and .beta.-endorphin to isolated O. degus vas deferens did not significantly change electrically-induced muscular twitches. Brain concentration of 14C morphine in the rat, as compared to O. degus, showed statistically significant differences. Pentazocine modified in EEG of O. degus, while morphine had no effect. Pimozide produced only a partial change of the pentazocine effect on EEG. This result is consistent with the view that pentazocine interacts with different opiate receptors.