Luteal phospholipase A2 activity increases during functional and structural luteolysis in pregnant rats.
We determined cytosolic phospholipase A2 activity of the corpus luteum during luteolysis in pregnant and post-partum rats. Phospholipase A2 activity and its metabolite prostaglandin F2alpha in the corpus luteum remarkably increased just before parturition and further rose transiently during post-partum structural luteolysis. The absence of a pups' suckling stimulus delayed corpus luteum involution, being associated with an altered fluctuation in phospholipase A2 activity and depressed prostaglandin F2alpha levels. Exogenous prolactin had a reversal effect. Pharmacological and immunochemical characterization suggests multiple isoforms of phospholipase A2 in a pregnant corpus luteum. These results show the increased phospholipase A2 activity and its possible implication in luteolysis in pregnant rats.
Kurusu
S
S
Laboratory of Veterinary Physiology, Kitasato University School of Veterinary Medicine and Animal Sciences, Towada, Aomori, Japan. kurusu@vmas.kitasato-u.ac.jp
Kaizo
K
K
Ibashi
M
M
Kawaminami
M
M
Hashimoto
I
I
D000818:Animals; D003338:Corpus Luteum / Q000166:cytology / Q000201:enzymology*; D004789:Enzyme Activation; D005260:Female; D007743:Labor, Obstetric; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
D010741:Phospholipases A; D054467:Phospholipases A2