RESUMO
Este trabalho objetivou verificar os efeitos agudos da aplicação endovenosa do extrato aquoso do Agaricus blazei Murill sobre a pressão arterial média (PAM) e a freqüência cardíaca (FC) de ratos anestesiados. Foram usados Rattus novergicus albinus, n = 6, anestesiados com tiopental sódico, traqueostomizados e canulados através da veia jugular e da artéria carótida. Foram injetadas as concentrações de 1,25 mg/kg, 2,50 mg/kg e 5,00 mg/kg do extrato aquoso em volume de 0,2 mL. A PAM foi registrada com um sistema Biopac, modelo MP100, e a FC com um eletrocardiógrafo ECG-4 Funbec. Os resultados foram obtidos no controle e nos tempos 15, 30, 45, 60 e 120s após a aplicação dos extratos. Os valores foram expressos em média ± EPM e analisados estatisticamente pelos testes "t" de Student-Newman-Keuls e Tukey (p<0,05). O extrato aquoso de A. blazei reduziu a PAM de maneira concentração dependente, sendo que a concentração de 1,25 mg/kg não provocou modificações significativas na PAM nem na FC; a de 2,50 mg/kg provocou diminuição da PAM aos 15s (p<0,01) e da FC aos 30s (p<0,001) e a de 5,00 mg/kg diminuiu a PAM aos 15s (p<0,001) e a FC aos 15 e 30s (p<0,001).
The aim of this paper was to verify the acute effects of the endovenous application of the aqueous extract of Agaricus blazei Murill on mean arterial pressure and heart rate of the anesthetized rats. The injected concentrations were: 1.25 mg/kg, 2.50 mg/kg and 5.00 mg/kg, in volume of 0.2 mL. The rats were anesthetized with sodium thiopental and, after tracheotomy, both jugular vein and carotid artery were cannulated. The MAP was recorded with a Biopac System, model MP100. The HR was obtained with an electrocardiograph model ECG-4 (Funbec). The records were made in the control and 15, 30, 45, 60 and 120s after the application of the different concentrations of the extracts. The values were expressed by mean ± SEM and by paired "t"-Student-Newman-Keuls and Tukey tests (p<0.05). The aqueous extract of the A. blazei decreased the MAP of dependent manner. The concentration of 1.25 mg/kg did not provoke effects; 2.50 mg/kg provoked decrease of the PAM at 15s (p<0.01) and of the HR at 30s (p<0.001) and 5.00 mg/kg provoked decrease of the PAM at 15s (p<0.001) and of the HR at 15 and 30s (p<0.001).
