RESUMO
BACKGROUND: Studies performed in 5 laboratories have shown that homeopathically prepared highly diluted thyroxin (10(-30)=30x) slowed down metamorphosis of highland amphibians. Metamorphosis of lowland amphibians, however, could be slowed down by a low dilution of thyroxin (10(-8)=8x) if animals had been artificially pretreated with thyroxin. OBJECTIVE: To combine the advantages of using animals from highland biotopes and hyperstimulation prior to treatment. ANIMALS AND METHODS: Rana temporaria from an alpine biotope were pretreated in an aqueous molecular thyroxin dilution (10(-8) parts by weight, hyperstimulation). This is supposed to accelerate metamorphosis. In accordance with the homeopathic idea of detoxification or cure, one group of these hyperstimulated animals was then treated with thyroxin 30x, and another group with water 30x. Experiments were performed by 4 independent researchers. RESULTS: As a trend, the thyroxin-30x animals metamorphosed more slowly than the water-30x animals. The number of thyroxin-30x animals that reached the 4-legged stage at defined points in time was slightly smaller at some but not all points in time, compared to control. This is in line with previous findings and can be discussed as an interesting result. Contrary to our working hypothesis, however, differences were not bigger than in the previous experiments in which animals had not been pretreated with thyroxin 10(-8). CONCLUSION: This study supports previous findings but does not prove the assumption that pretreatment of highland animals with molecular thyroxine improves the original protocol.