RESUMEN
The effect of stobadine on respiratory smooth muscles, blood pressure, heart rate and gastric acid secretion was studied and compared with the action of other antihistamines in vivo. Stobadine, as diphenhydramine, dithiadene and promethazine, but in contrast to cimetidine and ranitidine, prevented histamine from producing bronchospasm both after i.v. and oral administration. Based on the potency of its pharmacological action, diphenhydramine had a lower bioavailability after oral administration than the other antihistamines. Both cimetidine and ranitidine reduced the gastric acid secretion while stobadine was ineffective in this respect. None of the drugs studied antagonized histamine in reducing blood pressure, but all of them, with exception of promethazine and diphenhydramine, reduced mean arterial blood pressure. The results suggest that the action of stobadine on the respiratory and vascular smooth muscle effects is intermediate between that of diphenhydramine and dithiadene. In view of the minimal effect of stobadine on gastric acid secretion and its marked activity on airways, it is concluded that this drug predominantly acts on H1-receptors.
Asunto(s)
Carbolinas/farmacología , Antagonistas de los Receptores Histamínicos H1/farmacología , Antagonistas de los Receptores H2 de la Histamina/farmacología , Músculo Liso Vascular/efectos de los fármacos , Músculo Liso/efectos de los fármacos , Resistencia de las Vías Respiratorias/efectos de los fármacos , Anestesia , Animales , Presión Sanguínea/efectos de los fármacos , Bronquios/efectos de los fármacos , Ácido Gástrico/metabolismo , Cobayas , Frecuencia Cardíaca/efectos de los fármacos , Técnicas In Vitro , Masculino , Prometazina/farmacología , Ratas , Ratas EndogámicasRESUMEN
The action of pentacaine, a new prospective antiulcer drug with gastric cytoprotective activity, on gastric acid secretion was analysed and compared with the action of other antisecretory drugs. The drugs were given orally or intraduodenally to Wistar rats after pylorus ligation. The gastric acid secretion was studied under basal or stimulated (histamine, pentagastrin, carbachol) conditions. Oral administration of pentacaine, oxethazaine and procaine, in contrast to atropine, had no influence either under basal or stimulated conditions. However, intraduodenal administration of pentacaine significantly suppressed both the basal and stimulated gastric secretion. The present study suggests that the mechanism of antisecretory activity of pentacaine differs from that of anticholinergic and antihistaminergic drugs.
Asunto(s)
Carbamatos/farmacología , Ácido Gástrico/metabolismo , Animales , Antiulcerosos , Carbamatos/administración & dosificación , Cimetidina/farmacología , Duodeno , Femenino , Ratas , Ratas EndogámicasRESUMEN
The effects of pentacaine and heptacaine were compared with that of procaine on the isolated tracheal smooth muscle of guinea-pigs and anococcygeal muscle of rats. Pentacaine increased the initial tone of the tracheal smooth muscle. In higher concentration however pentacaine and heptacaine induced smooth muscle relaxation. Pentacaine diminished the action of histamine on the tracheal smooth muscle and both pentacaine and heptacaine depressed the effects of noradrenaline and acetylcholine on anococcygeal muscle.