133059-99-1

HCN channel

ZD7288 is a selective hyperpolarization-activated cyclic nucleotide-gated (HCN) channel blocker. ZD7288 inhibits glutamate release in a concentration-dependent manner. After incubation with 1, 5 and 50 µM ZD7288 for 24 hours, glutamate content in extracellular fluid is decreased to 69.0±2.8%, 31.4±2.0% and 4.4±0.3%, respectively (P<0.01, vs. DMEM/F12 group [100.2±4.2%]). After incubation with ZD7288 (25, 50, or 100 µM) for 20 minutes, 50 µM glutamate-induced [Ca ²⁺ ] _i rises are attenuated to 59.2±2.7%, 41.4±2.3% and 21.0±1.4%, respectively glutamate (P<0.01, vs. 50 µM glutamate group).

Application of ZD7288 0.1 µM at 5 minutes before high-frequency stimulation significantly decreases the amplitude of field excitatory postsynaptic potentials (fEPSPs), and this inhibitory effect is maintained throughout the recording period. Application of 0.1 µM ZD7288 30 minutes after high-frequency stimulation almost completely reverses the established long-term potentiation (LTP). Following application of ZD7288 (0.1 µM) 5 minutes before high-frequency stimulation, glutamate content is reduced to 74.9±8.0% (P<0.05, vs. normal saline group). Furthermore, application of 0.1 µM ZD7288 30 minutes after high-frequency stimulation markedly decreases the glutamate content to 77.0%±9.4% (P<0.05, vs. normal saline group).