Long-term stimulatory effects of a continuous infusion of LHRH agonist on testicular function in male red deer (Cervus elaphus).
Red deer stags were infused continuously with the LHRH agonist buserelin at 180-270 micrograms/day (1.2-1.8 micrograms/kg/day) for 72 days starting in late winter with the aim of suppressing reproductive function and inducing premature casting of the antlers. Contrary to expectation, the treatment resulted in a long-term stimulation of testicular activity lasting at least 2 months; the increases in plasma concentrations of testosterone were associated with an increase in aggressive behaviour and the development of rutting odour in the urine. The stags cast their antlers at the normal time in spring after the end of the treatments. The results indicate that the pituitary gonadotroph cells in the stag can continue to secrete LH in response to chronic exposure to an LHRH agonist and do not become rapidly desensitized. The effect of the agonist is therefore to cause significant stimulation of testicular activity which is a conspicuous response in the non-breeding season when the stags are already in a hypogonadal state.
D000818:Animals; D000999:Antlers; D002064:Buserelin / Q000494:pharmacology*; D003670:Deer / Q000502:physiology*; D008297:Male; D013268:Stimulation, Chemical; D013737:Testis / Q000187:drug effects / Q000502:physiology*
D002064:Buserelin