RESUMO
SO2-bronchitis, papaine-emphysema and paraquat fibrosis were induced in Wistar rats. Blood pressure, cardiac index, total peripheral resistance, arterial blood gas values, parameters of acid-base balance were determined. Effects of 0.1 and 0.3 microgram.-1.min-1 isoproterenol iv. infusion were examined. Morphologic alterations of the lungs were verified by histopathological examinations. All the parameters investigated were found to be normal in the control rats. The treated groups differed from the normal ones: an increased blood pressure was observed in emphysema and fibrosis. A decreased cardiac index was characteristic of chronic bronchitis, high cardiac index of emphysema, high TPR of bronchitis and arterial hypoxaemy of fibrosis. The groups reacted differently to beta adrenergic stimulation: in bronchitic and fibrotic rats the cardiac index was augmented, whereas in emphysematous ones the increase proved to be smaller. The effects of isoproterenol infusion can be related to the altered beta-receptor function in the various experimental pulmonary diseases.
Assuntos
Equilíbrio Ácido-Base/efeitos dos fármacos , Bronquite/tratamento farmacológico , Débito Cardíaco/efeitos dos fármacos , Isoproterenol/uso terapêutico , Enfisema Pulmonar/tratamento farmacológico , Fibrose Pulmonar/tratamento farmacológico , Animais , Bronquite/induzido quimicamente , Bronquite/fisiopatologia , Feminino , Masculino , Papaína , Paraquat , Enfisema Pulmonar/induzido quimicamente , Enfisema Pulmonar/fisiopatologia , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/fisiopatologia , Ratos , Ratos Endogâmicos , Dióxido de EnxofreRESUMO
The influence of propranolol, nalorphine and haloperidol on the breathing pattern and on the blood levels of cyclooxygenase products of anaesthetized spontaneously-breathing normotensive Wistar rats (WR) and of spontaneously hypertensive rats (SHR) were investigated. The respiratory rate was higher and the effective lung resistance was smaller in the SHR than in the WR. Breathing frequency decreased after nalorphine in both groups, while only in SHR after haloperidol. Propranolol augmented the dynamic lung resistance in both groups. The blood 6-keto-PGF1 alpha level was higher and the TXB2 level was lower in the SHR than in the WR. The central inspiratory activity as well as the levels of peripherally acting substances involved in the regulation of respiration and in the control of bronchial smooth muscle tone are different in the SHR and WR.
Assuntos
Epoprostenol/metabolismo , Haloperidol/farmacologia , Hipertensão/metabolismo , Nalorfina/farmacologia , Propranolol/farmacologia , Respiração/efeitos dos fármacos , Tromboxano A2/metabolismo , Animais , Capacidade Inspiratória , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos , Testes de Função RespiratóriaRESUMO
The trachea of rats anaesthetized with sodium pentobarbitone was cannulated and the air flow velocity and the pressure of the oesophagus were measured. In the spontaneously hypertensive rats the breathing frequency was higher, the tidal volume and the effective lung resistance were smaller than that of the normotensive Wistar rats. It seems that the neurohumoral control of respiration in SHR animals differs from that of normotensive rats.
Assuntos
Hipertensão/fisiopatologia , Pulmão/fisiopatologia , Respiração , Animais , Pulmão/inervação , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos , Testes de Função Respiratória , Sistema Nervoso Simpático/fisiopatologiaRESUMO
The effect of the enzyme inducer flumecinolum, m-trifluoromethyl-alpha-ethylbenzhydrol (Zixoryn), on aminophylline metabolism was examined in rats. Aminophylline plasma levels were determined by HPLC. Aminophylline T1/2 was 2.85 hours (r = 0.9353) in the pretreated group and 3.75 hours (r = 0.9471) in the untreated control group. Flumecinolum was found to accelerate the elimination of aminophylline and the effect became significant 3.92 hours after the administration of aminophylline.
