Emprego da levomepromazina no bloqueio da arritmia induzida pela adrenalina em cäes anestesiados pelo sevoflurano / The use of levomepromazine to blokade the arrhythmia induced by the epinephrine in dogs anesthetized with sevoflurane

Este experimento objetivou estudar o possível efeito antiarritmogênico da levomepromazina em cäes anestesiados pelo sevoflurano e submetidos a doses crescentes de adrenalina. Para tal, foram empregados 21 animais adultos, machos e fêmeas, sem raça definida e considerados sadios. Os cäes foram separados em dois grupos, sendo um de 11 (G1) e outro de 10 (G2) animais. O G1 recebeu, por via intravenosa, soluçäo salina a 0,9 por cento, na dose de 0,2ml/kg (placebo), seguida 15 minutos após, pela aplicaçäo de tiopental, pela mesma via, na dose suficiente para abolir o reflexo laringotraqueal. Procedeu-se à intubaçäo orotraqueal e iniciou-se a administraçäo de sevoflurano a 2,5V por cento, em circuito anestésico semi-fechado. Decorridos 20 minutos da induçäo anestésica, iniciou-se a administraçäo contínua, por via intravenosa, com emprego de bomba de infusäo, de soluçäo de adrenalina a 2 por cento, em doses crescentes de 1, 2, 3, 4 e 5µg/kg/min (M1 a M5, respectivamente), com incremento da dose a intervalos de 10 minutos. Para o G2, empregou-se a mesma metodologia substituindo-se o placebo por levomepromazina, na dose de 1mg/kg. Foi tomado o traçado eletrocardiográfico, na derivaçäo D2, a partir da induçäo da anestesia. Para efeito estatístico, foi considerado o número total de batimentos cardíacos de origem näo sinusal, coincidentes com cada dose de adrenalina. Os dados numéricos foram submetidos à Análise de Perfil, quando foi possível constatar que as médias do G1 foram crescentes de M1 a M3, diminuindo a partir deste último, até M5. No G2, foi encontrada arritmia ventricular sustentada apenas em M5. Os achados permitiram concluir que a levomepromazina minimiza a arritmia ventricular sustentada, induzida pela adrenalina em cäes anestesiados pelo sevoflurano.

Acute toxicity (LD50 and CD50) of lidocaine and prilocaine in combination with adrenaline and felypressin.

The toxicity of the combination of vasoconstrictors to local anaesthetic solutions has been debated since its first use in the beginning of this century. A combination of two vasoconstrictors to a local anaesthetic has been proposed by some researchers. In this study they were evaluated the acute toxicity (lethal dose 50%, convulsion dose 50%) and latency times of loss of righting reflex and convulsion as well as the duration of convulsion) of 2% lidocaine or 3% prilocaine, when administered in combination with adrenaline and felypressin at various concentrations. Lethal dose 50% studies showed that for both anaesthetics the solutions with higher concentrations of adrenaline were more toxic. The opposite was observed in the convulsion dose 50% studies. No alterations were observed in the control groups. All lidocaine solutions increased the latency of loss of righting reflex. The latency of convulsion was increased in some groups, but once the convulsion was achieved there was no difference in its duration. There was no statistical difference among prilocaine groups for any of the variables studied. Based on the experimental model studied, it was concluded that there is no advantage in the association of two vasoconstrictors concerning the toxicity of lidocaine and prilocaine solutions.

Effect of D-400, a herbal formulation, on blood sugar of normal and alloxan-induced diabetic rats.

Blood sugar levels of normal rats treated with D-400 showed significant reduction (P < 0.05) as compared to control groups. The fall was seen at one month and remained so uptill 3 months. Hyperglycemic response to adrenaline was significantly lowered (P < 0.05) following D-400 treatment. D-400 potentiated the hypoglycemia following tolbutamide treatment. Blood sugar remained persistently low in tolbutamide plus D-400 treated group after 3 and 4 hours (P < 0.05). In the alloxan-induced diabetic rats, a significant lowering of blood and urinary sugar was noticed on day 20, 30 and 40 following treatment with D-400 (P < 0.05). Liver glycogen depletion was significantly inhibited in the D-400 treated group (P < 0.025). D-400 has significantly potentiated (P < 0.05) the hypoglycemic action of insulin in alloxan-induced diabetic rats.

Effect of leaf extract from Clerodendron colebrookianum on blood pressure in rats.

Hypotensive effect of the extract of leaves of C. colebrookianum was investigated. An extremely bitter fraction was isolated, which gave positive test for alkaloids. The fraction produced fall of blood pressure in a dose dependent manner. The fall of blood pressure was blocked by atropine. Hypertensive effects of adrenaline and noradrenaline were slightly antagonised by the alkaloidal extract.