SHORTCOMMUNICATIONS Effect ofDexamethasone on Gonadotrophin Secretion in theGonadectomized SowandBoar

Saline solution or dexamethasone (DXM, 35uig/kg bodyweight) was injected intramuscularly twicedaily forfourdaysintoflve ovariectomized sows andfivecastrated boars. Blood samples froman indwelling jugular veincatheter were takenat15min intervals for12h priorto DXM injection andon thefourth dayof treatment inordertocompare the effect on variables describing the pulsatile secretion of luteinizing hormone (LH)andfollicle stimulating hormone(FSH).Dexamethasone treatment caused adecrease (p< 0.05) inthenumberofpulsatile episodes of LH secretion inbothgonadectomized boarsandsows resulting ina signifiLcantdecrease inmean concentrations. Follicle stimulating hormonesecretionparametersappearedto be unaffected byDXM injection inboth groupsofanimals. Itisconcluded that previously described differences inLH suppression inboarsandsows given glucocorticoids may beattributed to theinfluence ofgonadal hormones.