Luteinising hormone receptor kinetic and LH-induced prostaglandin production throughout the oestrous cycle in porcine endometrium.
The present studies were performed to determine the LH/hCG receptor concentration and to evaluate the LH effect on prostaglandin production in porcine endometrium throughout the oestrous cycle. LH/hCG receptors in cell membrane preparations of the endometrium were found from days 12-14 and 15-16 of the oestrous cycle but not in preparations from days 6-7 and 18-20 using the ligand radioreceptor assay. Western blot analysis revealed, however, that the endometrium from all stages of the oestrous cycle contains a 75-kDa immunoreactive LH receptor protein similar to corpora lutea. The incubation of endometrial explants with LH (0, 1, 10 and 100 ng x mL(-1)) resulted in an increase of 13,14-dihydro-15-keto-PGF2alpha accumulation in a dose-dependent manner on days 5, 10, 14 and 16 of the oestrous cycle. The most effective dose was 10 ng LH x mL(-1) on days 5-16, but the strongest effect was found on days 14 and 16 (7.40 +/- 0.14 versus 12.75 +/- 1.40 and 5.67 +/- 0.35 versus 9.4 +/- 1.25 ng x 100 mg(-1) tissue/6 h, respectively; P < 0.01). It was also observed that 10 and 100 ng x mL(-1) of LH significantly increased cyclo-oxygenase expression to 135.2 and 123.5% respectively, above the control value (P < 0.01) on day 16 of the oestrous cycle. Our data suggest that LH receptors are of physiological significance in the porcine endometrium, since LH induces cyclooxygenase synthesis and increases prostaglandin production.
Stepien
A
A
Division of Endocrinology and Pathophysiology, Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, Olsztyn.
Shemesh
M
M
Ziecik
A J
AJ
D000818:Animals; D015153:Blotting, Western; D002462:Cell Membrane / Q000378:metabolism; D015237:Dinoprost / Q000031:analogs & derivatives / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D004717:Endometrium / Q000378:metabolism*; D004790:Enzyme Induction / Q000187:drug effects; D004971:Estrus / Q000502:physiology*; D005260:Female; D007700:Kinetics; D007986:Luteinizing Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D011451:Prostaglandin-Endoperoxide Synthases / Q000096:biosynthesis; D011453:Prostaglandins / Q000096:biosynthesis*; D011869:Radioligand Assay; D011974:Receptors, LH / Q000378:metabolism*; D013552:Swine / Q000378:metabolism*
D011453:Prostaglandins; D011974:Receptors, LH; C008228:15-keto-13,14-dihydroprostaglandin F2alpha; D007986:Luteinizing Hormone; D015237:Dinoprost; D011451:Prostaglandin-Endoperoxide Synthases