Abstract
Inhibitory effects of cernitin pollen extract (CN-009), consisting of T-60 (a water-soluble extract) and GBX (an acetone-soluble extract) at a ratio of 20 : 1, were investigated in rat urethral smooth muscle and diaphragm. In the urethral smooth muscle, CN-009 (3.0×10-4 ?? 3.0×10-3 g/ml), T-60 and GBX (corresponding to CN-009) concentration-dependently inhibited the noradrenaline (NA, 10-5 g/ml)-induced contraction. According to Bürgi's calculation, the inhibition by T-60 and GBX was synergistic. On the other hand, GBX inhibited the NA-contraction non-competitively and also inhibited the K+-contraction. In contrast, T-60 tended to inhibit competitively, but did not affect the K+-contraction. In the diaphragm, CN-009 (5.25×10-3 ?? 2.1×10-2 g/ml) concentration-dependently inhibited the nerve stimulation-induced twitch response. T-60 (corresponding to CN-009) showed no effect, while GBX slightly inhibited the twitch response. The effects of T-60 and GBX were synergistic. The inhibitory effects of CN-009 (2.1×10-2g/ml) and GBX (1.0×10-2 g/ml) were specific against the nerve stimulation and were not antagonized by neostigmine (1.0×l0-5 g/ml). These results suggested that these effects were neither musculotropic nor competitive against ACh. In conclusion, CN-009 concentration-dependently inhibited the urethral contraction and the skeletal muscular twitch response. It was suggested that T-60 and GBX had different mechanisms and inhibited the response synergistically.
