Levinson S L
Prostaglandins. 1984 Aug;28(2):229-40. doi: 10.1016/0090-6980(84)90059-5.
Peptidoleukotrienes are known to be potent smooth muscle contractile agents in many tissues, including guinea pig uterus. In order to characterize the receptors at which the leukotrienes interact, guinea pig uteri were homogenized in 50mM Tris-HCl, pH 7.4 at 4 degrees C and centrifuged at 1000xg for 10 min. The supernatant was centrifuged at 40,000 xg and the washed pellet was used to measure the binding of 3H-LTC4 and 3H-LTD4. Specific binding of 3H-LTD4 was not detected, but specific, saturable binding of 3H-LTC4 was measured at 4 degrees C, was complete in 10 min. and was rapidly reversible on addition of unlabeled LTC4. Binding was linear with protein concentration and stimulated by CaCl2 and L-serine borate. Scatchard and kinetic analysis of binding in the presence of calcium suggested a Kd of 10-12 nM. LTC4 was a more potent competitor of binding than LTD4 (IC50 - 40nM and 30 microM, respectively). FPL 55712 inhibited binding from 10-100 microM but stimulated binding at lower concentrations. Thus, the guinea pig uterus has specific receptors for LTC4, but not LTD4, that can be demonstrated by radioligand binding.
已知肽白三烯在包括豚鼠子宫在内的许多组织中是强效的平滑肌收缩剂。为了表征白三烯相互作用的受体，将豚鼠子宫在4℃下于50mM Tris-HCl（pH 7.4）中匀浆，并以1000xg离心10分钟。将上清液以40,000 xg离心，洗涤后的沉淀用于测量3H-LTC4和3H-LTD4的结合。未检测到3H-LTD4的特异性结合，但在4℃下测量到3H-LTC4的特异性、可饱和结合，10分钟内完成，加入未标记的LTC4后迅速可逆。结合与蛋白质浓度呈线性关系，并受CaCl2和L-丝氨酸硼酸盐刺激。在钙存在下结合的Scatchard和动力学分析表明Kd为10-12 nM。LTC4比LTD4是更强效的结合竞争剂（IC50分别为40nM和30μM）。FPL 55712在10-100μM时抑制结合，但在较低浓度时刺激结合。因此，豚鼠子宫具有LTC4的特异性受体，但不具有LTD4的特异性受体，这可以通过放射性配体结合来证明。
