A CONTRACTIVE INGREDIENT OF UTERI OBTAINED FROM THE CHINESE DRUG KUANG-TI-LUNG (LUMBRICUS KWANGTANGENSIS)

According to Huang Wen-k'uei's method, we separated an oxytocic ingredient from Kwang-Ti-lung.It was a faintly yellow, hygroscopic, needle crystal, and its content in Kwang-Ti-lung was about 0.2 per cent. The crystal at the concentration of 1:250000 produced a progressive rise on the tonus of isolated uterine horns of rats or guinea pigs, and at the concentration of 1:83000, a spastic contraction was apparent. The solution of crystal by intravenous injection to the pregnant or non-pregnant anaesthetized rabbits (1 mg/kg) produced a considerable rise on the tonus of uteri in situ that lasted for 1.5—3 hours, and at a dosage of 8—10 mg/kg, the tonus of uteri raised promptly and the rabbits were dead owing to the blood pressure falling rapidly to zero. From 15 to 45 minutes after intravenous injections (3—6 mg/kg) or oral administrations (10—20 mg/kg) with the solution of crystal to 9 rabbits of chronic uterine fistula, the uterine contractions markedly potentiated; the effect lasted for 1.5—3 hours intravenously and was retained for 7 hours or more orally. The crystal produced also a strong contraction on the rabbit's intestines or the rat's hinder leg vessels, but an extremely weak effect on the guinea pig's bronchial muscles. The LD₅₀ in mice was found to be 38.7mg/kg for the solution, given by intravenous injection.