The initial phase of GnRH‐stimulated LH release from pituitary cells is independent of calcium entry through voltage‐gated channels

[摘要]

Kinetic studies on gonadotropin-releasing hormone (GnRH)-stimulated luteinizing hormone (LH) release were undertaken using rat and chicken pituitary cell cultures. In response to continuous GnRH stimulation, a biphasic pattern of LH release was demonstrated. The two phases showed different susceptibility to the voltage-gated Ca²⁺ channel blockers D600 and nifedipine. The first (transient) phase of LH release was unaffected by the Ca²⁺ channel blockers whereas the second (sustained) phase was inhibited by both drugs. These results indicate that the initial phase of LH release is independent of Ca²⁺ entry through voltage-gated Ca²⁺ channels and may depend on mobilisation of intracellular Ca²⁺ or entry of extracellular Ca²⁺ through another mechanism.

[学科分类] 生物化学/生物物理

[关键词] Kinetics;Gonadotropin-releasing hormone;Luteinizing hormone;Ca2+ channel;Ca2+ influx;Hormone release;(Pituitary cell)