= Gonadotroph
A <gonadotroph> is a hormone-producing <biological cell> of the <anterior pituitary> that synthesizes the <gonadotropins> <luteinizing hormone> (<LH>) and <follicle-stimulating hormone>. These products act on the <gonads>. Its upstream stimulus, <gonadotropin-releasing hormone> (<GnRH>), is made by hypothalamic <neurons> and delivered through the <hypophyseal portal system>. The incoming signal and the gonadotroph's secreted products are distinct <hormones>.<Anatomy and Physiology 2e by J. Gordon Betts and others>[Section17.3: anterior-pituitary regulation; Follicle-Stimulating Hormone and Luteinizing Hormone]{ref}
A <gonadotroph> responds to a time-varying input, rather than merely counting the total amount of <GnRH> delivered. In a 1985 experiment, investigators surgically separated the pituitary from hypothalamic control in <sheep> and supplied equal-sized <GnRH> pulses hourly or every two hours. The less frequent schedule produced larger individual <LH> responses. This demonstrates that pulse timing can change the gland's output; it does not imply that doubling the interval doubles every response in every animal.<GnRH pulse frequency determines LH pulse amplitude by altering the amount of releasable LH in the pituitary glands of ewes by Iain J. Clarke and James T. Cummins>[Summary: disconnected pituitaries,250ng pulses and LH-response comparison]{ref}
For an experimental interpretation, distinguish pulse amplitude, interval and daily dose. Keeping the amount per pulse fixed while halving pulse frequency also halves daily input. Measuring the gland's <LH> output tests a physiological response of its secretory cells, but does not by itself identify every intracellular step of the response.
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