Plasma progesterone in reindeer in relation to ovariectomy and hysterectomy.
Four semi-domesticated reindeer were ovariectomized and 3 both ovariectomized and hysterectomized, 30-70 days before expected parturition. Anaesthesia with etorphine/propyonylphenthiazine was followed by an increase in the plasma concentration of progesterone of peripheral blood. The concentration of progesterone returned to pre-anaesthetic values before ovariectomy. Ovariectomy did not result in any substantial change in the plasma progesterone concentration within an observation period of 35-120 min. Hysterectomy was followed by a marked decrease in peripheral plasma progesterone within 60 min. The progesterone concentration in ovarian venous blood was slightly higher than the jugular venous blood in 1 animal and 150 and 400 times higher in the 2 other animals examined. Thus, despite lack of marked changes of progesterone in jugular venous blood upon ovariectomy, it is concluded that the ovaries are a major production site of progesterone in pregnant reindeer. The progesterone in uterine venous blood was close to that in the jugular vein in 1 animal, and slightly higher in 2 others. This observation, and the maintenance of pregnancy in spite of ovariectomy in 2 out of 4 animals, point to the foeto-placental unit as an additional source of progesterone production.
Sjaastad
O V
OV
Department of Physiology and Nutrition, Norwegian College of Veterinary Medicine, Oslo.
Blom
A K
AK
Austad
R
R
Oen
E O
EO
D000818:Animals; D005260:Female; D007044:Hysterectomy / Q000662:veterinary; D010052:Ovariectomy / Q000662:veterinary; D010053:Ovary / Q000378:metabolism*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000378:metabolism*; D011374:Progesterone / Q000097:blood*; D012053:Reindeer / Q000378:metabolism*
D011374:Progesterone