Effect of sexual arousal on gonadotrophin-releasing hormone, luteinizing hormone and follicle-stimulating hormone secretion in the stallion.
In an experiment conducted late in the physiological breeding season, 5 stallions were fitted with indwelling pituitary venous cannulae that permitted unobtrusive collection of blood coming from the pituitary and the hypothalamo-hypophyseal portal vessels. The next day, blood samples were collected at 5 min intervals for several hours while the stallions were resting. Pulses of gonadotrophin-releasing hormone (GnRH), follicle-stimulating hormone (FSH) and luteinizing hormone (LH) occurred approximately once per hour. After this, an oestrous mare was brought into contact with each stallion for 8-30 min. This exposure rapidly induced pulses of GnRH, FSH and LH secretion in all stallions, showing that sexual arousal stimulates the hormones of the reproductive axis.
Irvine
C H
CH
Department of Animal and Veterinary Sciences, Lincoln University, Canterbury, New Zealand.
Alexander
S L
SL
D000818:Animals; D001143:Arousal; D005640:Follicle Stimulating Hormone / Q000097:blood / Q000378:metabolism*; D007987:Gonadotropin-Releasing Hormone / Q000097:blood / Q000378:metabolism*; D006064:Gonadotropins, Equine / Q000378:metabolism*; D006736:Horses / Q000502:physiology*; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism*; D008297:Male; D012726:Sexual Behavior, Animal / Q000502:physiology*
D006064:Gonadotropins, Equine; D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone