RESUMO
The effects of buprenorphine on castor-oil-induced diarrhoea, gastrointestinal transit and ethanol-induced gastric lesions in rats were compared to the same effects of morphine. Like morphine, buprenorphine prevented castor-oil-induced diarrhoea. However, it has no effect on gastrointestinal transit per se but prevented the inhibitory action of morphine. While morphine protected against ethanol-induced gastric lesions, buprenorphine aggravated them. It is suggested that different types/subtypes of opioid receptors may be involved in the gastrointestinal actions of buprenorphine.
Assuntos
Buprenorfina/farmacologia , Diarreia/tratamento farmacológico , Sistema Digestório/efeitos dos fármacos , Morfina/farmacologia , Animais , Relação Dose-Resposta a Droga , Masculino , Naloxona/farmacologia , Ratos , Ratos WistarRESUMO
Morphine has a significant protective effect on ethanol-induced gastric lesions. This effect is antagonized by naloxone, suggesting that it is mediated by opioid receptors. In the rat, mu-receptors have been shown to be involved in other gastrointestinal actions of opioids. However, the potent partial agonist at mu-receptors, buprenorphine, not only failed to protect but actually aggravated ethanol-induced lesions at higher doses. The gut-selective mu-agonist, loperamide, also did not have a protective effect, while the mixed opioid, pentazocine, which has an antagonistic action at mu-receptors, by itself protected against ethanol-induced gastric lesions. Our results suggest that mu-receptors are probably not involved in the gastric cytoprotective action of opioids.
Assuntos
Etanol/toxicidade , Morfina/farmacologia , Receptores Opioides mu/efeitos dos fármacos , Estômago/efeitos dos fármacos , Administração Oral , Animais , Buprenorfina/administração & dosagem , Buprenorfina/farmacologia , Modelos Animais de Doenças , Interações Medicamentosas , Injeções Intraperitoneais , Loperamida/administração & dosagem , Loperamida/farmacologia , Masculino , Morfina/administração & dosagem , Morfina/uso terapêutico , Naloxona/administração & dosagem , Naloxona/farmacologia , Pentazocina/administração & dosagem , Pentazocina/farmacologia , Distribuição Aleatória , Ratos , Ratos Wistar , Receptores Opioides mu/metabolismo , Estômago/citologia , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/tratamento farmacológicoRESUMO
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.
Assuntos
Trifosfato de Adenosina/fisiologia , Etanol/farmacologia , Hemorragia Gastrointestinal/induzido quimicamente , Hemorragia Gastrointestinal/prevenção & controle , Morfina/farmacologia , Canais de Potássio/fisiologia , Animais , Diazóxido/farmacologia , Glibureto/farmacologia , Masculino , Naloxona/farmacologia , Fentolamina/farmacologia , Canais de Potássio/efeitos dos fármacos , Prazosina/farmacologia , Ratos , Ratos Wistar , Receptores Adrenérgicos alfa/efeitos dos fármacos , Receptores Adrenérgicos alfa/fisiologiaRESUMO
We have compared the effect of the converting enzyme inhibitors, captopril and enalapril, on two models of gastric ulcers, viz; ethanol and oxyphenbutazone-induced lesions in rats. Both captopril and enalapril did not affect ethanol-induced lesions. While captopril significantly protected against oxyphenbutazone-induced lesions, enalapril aggravated the lesions. This difference is probably due to the lack of the protective sulfhydryl group in the chemical structure of enalapril.
Assuntos
Captopril/farmacologia , Enalapril/farmacologia , Etanol , Oxifenilbutazona , Úlcera Gástrica/prevenção & controle , Animais , Masculino , Ratos , Ratos Endogâmicos , Úlcera Gástrica/induzido quimicamenteRESUMO
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
This study was conducted to compare the analgesic efficacy of four commonly used analgesics namely ibuprofen, analgin, paracetamol and aspirin in post-episiotomy pain. The subjects were healthy postpartum women on the obstetric service of Goa Medical College, each of whom received only one experimental medication. Subjective reports were used as indices of pain intensity or relief. Ibuprofen was found to be the most effective analgesic in post-episiotomy pain followed by analgin and paracetamol in that order. Surprisingly, aspirin was found to be no better than placebo.
