0000000000023284
AUTHOR
Rafael Blasco
Selective inhibition of calcium entry induced by benzylisoquinolines in rat smooth muscle.
Abstract The mechanism of relaxant activity of six benzylisoquinolines was examined in order to determine the minimal structural requirements that enable these compounds to have either a non-specific action like papaverine or an inhibitory activity on calcium entry via potential-operated channels. All the alkaloids tested totally or partially relaxed KCl-depolarized rat uterus and inhibited oxytocin-induced rhythmic contractions. Only glaucine and laudanosine inhibited K+-induced uterine contractions more than oxytocin-induced uterine contractions. In Ca+-free medium, sustained contractions induced by oxytocin or vanadate were relaxed by the alkaloids tested except for glaucine and laudanos…
El dilema del patrimonio paleontológico: ¿es posible su protección a través de las leyes de conservación de espacios naturales?
En España, el patrimonio paleontológico puede ser protegido aplicando figuras de la legislación medioambiental o de la cultural, dependiendo si es considerado como perteneciente al patrimonio natural o histórico, respectivamente. La naturaleza intrínseca de los fósiles (origen, naturaleza y localización) permite englobarlos como un elemento de la geodiversidad (patrimonio geológico-paleontológico). Parece pues más adecuado incluir al patrimonio paleontológico como perteneciente al contexto de lo natural y no lo cultural. Por esta razón creemos más conveniente su protección a través de la legislación medioambiental. En la Comunidad Valenciana, la Ley 11/1994, de espacios naturales protegidos…
Inhibition of calcium entry induced by cularines and isocrasifoline in uterine smooth muscle.
Abstract The effects of nifedipine, papaverine and four benzylisoquinoline alkaloids (cularine, cularidine, celtisine and isocrasifoline) were studied in isolated rat uterus in order to clarify the mechanism of their relaxant action. All the compounds tested completely relaxed KCl-induced contractions and totally or partially inhibited oxytocin-induced rhythmic contractions. Only papaverine acted intracellularly, promoting relaxation of contractile responses induced by oxytocin or vanadate in a Ca 2+ -free medium. In spite of the structural relationship between papaverine and the other alkaloids, the mechanism of their relaxant action is not the same. The activities of cularine derivatives …
Study of the antioedema activity of some seaweed and sponge extracts from the mediterranean coast in mice
Chloroform and methanol extracts of ten marine species, seven seaweeds and three sponges, have been studied for possible, antioedema activities. The extracts were administered either topically or orally on TPA-induced mouse ear oedema and on carrageenan mouse paw oedema, respectively. The most interesting seaweed extracts were found to be from Corallina elongata, Galaxaura oblongata, Laurencia obtusa and Udotea petiolata, where both extracts of each species induced a large antioedema effect in both models employed. None of the sponges assayed demonstrated antiinflammatory effects on carrageenan mouse paw oedema, however, some extracts elicited an inhibition of the oedema developed by TPA.