The human placenta as a target tissue for glucagon.
Glucagon's effect on the placenta was studied in cultured human term trophoblast and in homogenized term and first-trimester placentas. In studies with cultured term trophoblast, glucagon stimulated the generation of cyclic AMP and estradiol secretion and inhibited placental lactogen secretion. Incubation of homogenates of term and of first-trimester placenta with 0.5 mM dibutyryl cAMP revealed a marked decrease of pyruvate kinase activity. Glucagon produced a similar decrease in first-trimester homogenates, but failed to affect term placentas. The present demonstration of the placenta as a target tissue for glucagon suggests an active contribution of the trophoblast to energy metabolism during pregnancy.
Perlman
R
R
Department of Pharmacology, Technion-Israel Institute of Technology, Haifa.
Halabi
C
C
Bick
T
T
Hochberg
Z
Z
D003994:Bucladesine / Q000494:pharmacology; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism; D005260:Female; D005934:Glucagon / Q000494:pharmacology*; D006801:Humans; D010920:Placenta / Q000187:drug effects*; D010928:Placental Lactogen / Q000378:metabolism; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011263:Pregnancy Trimester, Third; D011770:Pyruvate Kinase / Q000378:metabolism; D014327:Trophoblasts / Q000187:drug effects
D004958:Estradiol; D003994:Bucladesine; D005934:Glucagon; D010928:Placental Lactogen; D000242:Cyclic AMP; D011770:Pyruvate Kinase