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Module 10: Figure somatotroph regulation

Regulation of growth hormone (GH) secretion by somatotrophs.

Somatotrophs have a membrane oscillator that spontaneously generates repetitive slow waves of membrane depolarization (see Vm trace) that are responsible for the periodic bursts of Ca2+ that triggers the release of growth hormone (GH). Growth hormone-releasing hormone (GHRH) acts through the cyclic AMP signalling pathway to control the background Na+ (Nab) channel responsible for the pacemaker depolarization. See text for further details.