BAY K 8644 at concentrations of 10(-10)-10(-6) M had a stimulant effect on the spontaneous electrical and contractile activity of smooth muscle preparations from cat and guinea pig stomach. 2. Nifedipine (10(-6) M) antagonized the BAY K 8644-induced spike potentials and the related phasic contractions. 3. Neither the excitatory nor the inhibitory effect of BAY K 8644 was significantly influenced by atropine (10(-7) M), phentolamine (10(-7) M), propranolol (10(-7) M) or TTX (10(-6) M). 4. TEA (10(-3) M) abolished the inhibitory effect of BAY K 8644 on the spike generation and increased the amplitude of the phasic contractions.
摘要
浓度为10⁻¹⁰ - 10⁻⁶ M的BAY K 8644对猫和豚鼠胃平滑肌制剂的自发电活动和收缩活动有刺激作用。2. 硝苯地平（10⁻⁶ M）拮抗BAY K 8644诱导的锋电位和相关的相性收缩。3. 阿托品（10⁻⁷ M）、酚妥拉明（10⁻⁷ M）、普萘洛尔（10⁻⁷ M）或TTX（10⁻⁶ M）对BAY K 8644的兴奋或抑制作用均无显著影响。4. 四乙铵（10⁻³ M）消除了BAY K 8644对锋电位产生的抑制作用，并增加了相性收缩的幅度。
