The pulsatile rather than continuous secretion of GnRH is essential for maintaining gonadotropin secretion. If GnRH is administered as a continuous infusion rather than pulsatile delivery, the expected pituitary response is:

• A Sustained increase in LH and FSH due to constant receptor stimulation
• B Initial rise followed by desensitization (downregulation) of GnRH receptors and suppression of LH and FSH ✓
• C Selective suppression of FSH with maintenance of LH secretion
• D Conversion of tonic to surge-type GnRH secretion pattern

Explanation

GnRH receptor signaling requires pulsatile stimulation to maintain receptor sensitivity. Continuous GnRH exposure causes homologous desensitization through receptor downregulation (internalization and reduced receptor expression), leading to suppression of both LH and FSH after an initial stimulatory phase. This physiological principle is exploited therapeutically with GnRH agonists (e.g., leuprolide) administered continuously to suppress gonadotropins in prostate cancer, endometriosis, and precocious puberty. Pulsatile GnRH therapy, conversely, is used to induce ovulation in hypothalamic amenorrhea.

Reference: Guyton & Hall, Textbook of Medical Physiology, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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