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 Udoka p e t i o b , 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.

No 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 laudanosine indicating no inhibitory effect on intracellular calcium release. Those alkaloids containing an unsaturated heterocyclic ring (papaverine, papaverinol, papaveraldine, N-methylpapaverine and dehydropapaverine) exhibited a more specific activity than those with a tetrahydroisoquinoline ring.

Hypertension caused by calcium deficiency in the diet has been linked with an increase in parathyroid hormone (PTH) and calcitriol levels. We evaluated arterial blood pressure (ABP), PTH, and calcitriol in normotensive Sprague-Dawley rats (SDR) and in spontaneously hypertensive rats (SHR) fed from weaning on a control diet with a normal calcium content (1%) or a low-calcium diet (0.1%). The calcemia was also measured in the rats by colorimetric methods. The low-calcium diet decreased the calcemia in both strains and brought about an increase in the ABP which was significant in adult SDR and particularly noticeable during the early hypertensive phase in SHR. The rats fed on this diet had higher hormonal plasma levels when compared with the corresponding values in rats fed on the control diet. In particular, the SDR fed on the low-calcium diet showed much higher PTH (122.6 ± 31.0 pg/ml, p ≤ 0.05) and calcitriol (458.0 ± 13.1 pg/ml, p ≤ 0.01) values than the SDR fed on the control diet (PTH 31.7 ± 2.80 pg/ml; calcitriol 292.1 ± 17.5 pg/ml). These endocrine alterations could justify the increase in ABP caused by dietary calcium deficiency in normotensive rats. Nevertheless, the results of this study indicate that the modifications of the ABP caused by the low-calcium diet in SHR could not be correlated with significant increases in these hormones.

No abstract