Effects of dauricine (Dau) on the physiologic properties of myocardium were studied in cat papillary muscles. Dau (32 μM) decreased the force of contraction to 72 ±3 % (P<0.01) and depressed markedly the excitability as well as epinephrine-induced automaticity, even in lower concentration (5 μM). It also prolonged the functional refractory period from 315±13 ms to 362±18 ms (P< 0.05). The results obtained indicate that Dau possesses calcium antagonistic effect as well as an inhibitory action on Na⁺ current in cat papillary muscles.

Intrauterine devices (IUDs) are widely used in China for contraception, but uterine bleeding is the most common side effect. This study is to observe the effects on menstrual blood loss (MBL) of the 4 types of IUDs —stainless steel ring (SR), Shanghai copper T 200 (CuT), Shanghai copper V 200 (CuV) and Beijing copper V 200 (BV) —which are commonly used in China. MBL was determined in 82 subjects in pre and postinsertion periods. After insertion, the mean MBL of all types of IUDs were significantly higher than that before insertion (P<0.01). The range was 11.7—425 ml, and the increased percentage of MBL was 23–109%. It did not return to the preinsertion level in the 12th menstrual period. The Hb concentration remained essentially unchanged during the study. The increased mean MBL and incidence of menorrhagia in the postinsertion period showed lower bleeding effect in the SR and BV groups than the CuT and CuV ones. SR may be IUD of choice for long term use if the expulsion rate and contraceptive efficacy can be improved. The bleeding problem of CuT and CuV remains to be solved in the future.