RESUMO
It is well known that self-mutilating behavior (SMB) is developed in rats and humans during the daily treatment with d-amphetamine. Accordingly, in this work it was found that the daily treatment with 7.5 mg/kg d-amphetamine induced in rats a progressive appearance of SMB. Lower doses (5.0 mg/kg) were uneffective and higher doses (10 mg/kg) produced a pattern of SMB in which the mutilation induced at the beginning of the d-amphetamine administration disappears completely as the treatment progresses. Interestingly, it was also found that REM sleep deprivation (48 h) potentiated significantly the SMB induced by the daily administration of 7.5 mg/kg d-amphetamine, and to lesser extent, the SMB induced by the daily treatment with 10 mg/kg d-amphetamine. R(+)-SCH-23390 a D1 dopamine (DA) receptor antagonist blocked completely or abolished the SMB induced by 7.5 mg/kg d-amphetamine in REM sleep deprived rats while (+/-)-sulpiride a D2 DA receptor antagonist had only a partial blocking effect. Haloperidol a D1/D2 DA receptor antagonist behaved as a D1 antagonist. Our results indicate that REM sleep deprivation enhances the SMB induced by the daily administration of d-amphetamine and suggest the involvement of D1 DA receptors in the mechanism underlying the SMB. A role of REM sleep deprivation is also suggested in the appearance of self-mutilating episodes in d-amphetamine addicts.
Assuntos
Comportamento Autodestrutivo/induzido quimicamente , Comportamento Autodestrutivo/fisiopatologia , Privação do Sono/fisiologia , Sono REM/fisiologia , Animais , Benzazepinas/farmacologia , Estimulantes do Sistema Nervoso Central , Dextroanfetamina , Dopamina/fisiologia , Antagonistas de Dopamina/farmacologia , Haloperidol/farmacologia , Masculino , Ratos , Ratos Wistar , Receptores Dopaminérgicos/fisiologia , Comportamento Autodestrutivo/tratamento farmacológico , Sulpirida/farmacologiaRESUMO
The objective of this work is to investigate the hypoglycemic effect of 12 "antidiabetic" plants used in Mexico. The studies were performed using 27 healthy rabbits with the gastric administration of water, tolbutamide or decoction of the "antidiabetic" plant before the induction of temporary hyperglycemia by subcutaneous injection of 50% dextrose solution (4 ml/kg of weight) at the beginning of the experiment and after 60 min. Blood glucose was determined every 60 min for a period of 5 h. Tolbutamide and eight of the studied plants decreased significantly the hyperglycemia as compared with control test (water) (p < 0.05). The strongest effect was yielded by Guaiacum coulteri, followed by Marrubium vulgare, Crataegus pubescens, Cynodon dactylon, Calea zacatechichi, Buddleia americana, Bauhinia divaricata and Coix lachryma. The decrease of hyperglycemia caused by Physalis phyladelphyca, Pavonia schiedeana and Eucaliptus globulus was not significant (p > 0.05). Urtica dioica increased glycemia slightly.
Assuntos
Hiperglicemia/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Plantas Medicinais , Animais , Glicemia/análise , Teste de Tolerância a Glucose , Hiperglicemia/induzido quimicamente , Hipoglicemiantes/isolamento & purificação , Masculino , México , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/uso terapêutico , Coelhos , Tolbutamida/uso terapêutico , ÁguaRESUMO
To assess the hypoglycemic activity mechanism of some plants used empirically by the Mexican population as antidiabetics, traditional preparations of Cucurbita ficifolia, Guaiacum coulteri, Lepechinia caulescens, and Psacalium peltatum, water, tolbutamide, and Regular Insulin were administered to three groups of rabbits each: 1. Healthy rabbits with temporary hyperglycemia induced by the subcutaneous administration of glucose. 2. Rabbits with moderate diabetes (fasting glycemia 150-300 mg/dl), induced with alloxan. 3. Rabbits with severe diabetes (fasting glycemia higher than 400 mg/dl), induced with alloxan. The plant preparations had a hypoglycemic effect similar to tolbutamide in healthy and mild diabetic rabbits and had no effect in severely diabetic rabbits. These results suggest that some pancreatic function or the presence of insulin is required for the hypoglycemic activity of these plants.
Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Plantas Medicinais , Animais , Avaliação Pré-Clínica de Medicamentos , Hiperglicemia/tratamento farmacológico , Hipoglicemiantes/isolamento & purificação , México , Extratos Vegetais/uso terapêutico , Coelhos , Tolbutamida/uso terapêutico , ÁguaRESUMO
The purpose of this work is to look for the hypoglycemic effect of 12 plants most used in Mexico for controlling diabetes mellitus. The studies were realized in 27 rabbits submitted weekly to glucose tolerance tests after gastric administration of water, tolbutamide or a preparation of the plant. The results showed that tolbutamide and studied plants (except Aloe barbadensis) decreased significantly (p less than 0.05) the area under glucose tolerance curve, in relation with the water control. The strongest effect was yielded by Psacalium peltatum (27.9%), followed by Curcubita ficifolia (26.4%), Lepechinia caulescens (26.0%), Opuntia streptacantha (21.4%), Slanum verbascifolum (21.1%), Teucrium cubense (19.4%), Cecropia obtusifolia (18.9%), Phaseolus vulgaris (18.5%), Tecoma stans (17.5%), Eriobotrya japonica (17.2%), Salpianthus macrodonthus (15.0%), tolbutamide (14.3%), and Aloe barbadensis (1.4%). Our results point out that the majority of the plants most used by the Mexican population to control diabetes mellitus have an evident hypoglycemic action.