RESUMO
We studied the effect of the angiotensin converting enzyme inhibitor, captopril, on two models of gastric ulcers; oxyphenbutazone and ethanol-induced lesions. There was a significant protective effect against oxyphenbutazone-induced ulcers, which was prevented by prior administration of indomethacin. Captopril, however, failed to protect against ethanol-induced lesions. These findings are discussed in the light of captopril being a sulfhydryl compound with prostaglandin-releasing activity.
Assuntos
Captopril/farmacologia , Etanol , Oxifenilbutazona , Úlcera Gástrica/prevenção & controle , Animais , Indometacina/farmacologia , Masculino , Ratos , Ratos Endogâmicos , Úlcera Gástrica/induzido quimicamenteRESUMO
We studied the effect of five antihypertensive drugs on ethanol-induced gastric haemorrhagic lesions in rats. While hydralazine aggravates these lesions, nifedipine and propranolol have a protective action. On the other hand, enalapril and prazosin have no effect. Thus the effects of antihypertensive drugs on ethanol-induced lesions do not always correlate with their reported actions on gastric mucosal blood flow.
Assuntos
Anti-Hipertensivos/farmacologia , Etanol/efeitos adversos , Mucosa Gástrica/irrigação sanguínea , Hemorragia Gastrointestinal/tratamento farmacológico , Gastropatias/tratamento farmacológico , Animais , Pressão Sanguínea/efeitos dos fármacos , Interações Medicamentosas , Mucosa Gástrica/efeitos dos fármacos , Hemorragia Gastrointestinal/induzido quimicamente , Hemorragia Gastrointestinal/prevenção & controle , Hidralazina/farmacologia , Masculino , Propranolol/farmacologia , Ratos , Ratos Wistar , Gastropatias/induzido quimicamente , Gastropatias/prevenção & controle , Vasodilatadores/farmacologiaRESUMO
Endogenous nitric oxide has been proposed as one of the mediators of gastric cytoprotection. We studied the effect of the vasodilator hydralazine which acts via nitric oxide and thus is expected to have a gastroprotective action. However, hydralazine aggravates ethanol-induced gastric lesions. This effect is not influenced by pretreatment with the selective alpha 1 adrenergic antagonist prazosin but is abolished by the angiotensin converting enzyme inhibitor, captopril suggesting the involvement of the renin-angiotensin system.
Assuntos
Etanol/toxicidade , Hemorragia Gastrointestinal/induzido quimicamente , Hidralazina/farmacologia , Gastropatias/induzido quimicamente , Estômago/efeitos dos fármacos , Animais , Captopril/farmacologia , Interações Medicamentosas , Hidralazina/administração & dosagem , Masculino , Prazosina/farmacologia , Ratos , Ratos EndogâmicosRESUMO
Morphine has a significant protective effect on ethanol-induced gastric lesions. This effect is antagonized by naloxone, suggesting the involvement of opioid receptors. The ATP-dependent potassium channel blockers glibenclamide and phentolamine have different effects on this action of morphine. While glibenclamide potentiates the gastroprotective effect of morphine, phentolamine antagonizes it. However, both prazosin and yohimbine do not affect the gastroprotective action of morphine, suggesting that the influence of phentolamine is not mediated by alpha-adrenoceptors. As phentolamine also prevented the gastroprotective effect of the ATP-dependent K+ channel opener diazoxide, our results suggest that ATP-dependent K+ channels may be involved in the gastro-protective action of morphine.