Nitric oxide induces endometrial secretion at implantation time.
BACKGROUND
Uterine cervical secretory cells receive a sympathetic cholinergic secretomotor innervation. Glandular nitric oxide (NO) production has been proposed to be a prerequisite for muscarine-induced carbohydrate secretion from endometrial glands and cervical glands at ovulation time and from the seminal vesicle glands. Nitric oxide has also been suggested to have a significant role in the process of implantation and early pregnancy in the mouse, a process, which has also been compared with an inflammatory response.


METHODS
The carbohydrate secretion from everted guinea pig uterine horns placed in organ baths was estimated. Polymerase chain reaction was performed in order to identify the isoforms of nitric oxide synthase (NOS). results. Carbamylcholine chloride (Carbachol) induced carbohydrate secretion of the endometrium, whereas L-NNA and L-NAME inhibited the Carbachol-induced secretion. The isomer D-NAME had no effect on Carbachol-induced secretion. The NO donor GTN induced carbohydrate secretion of the endometrium. The addition of the nitrergic inhibitor of soluble guanylyl cyclase (sGC) ODQ to Carbachol and to the NO donor GTN gave a reduced response. No synergism was seen when the sGC stimulator YC-1 was applied together with Carbachol. Three isoforms of NOS - endothelial NOS (eNOS), cytokine-inducible NOS (iNOS), and neuronal (nNOS) - were identified at implantation time and may take place in the endometrial cell.


CONCLUSIONS
The results of this study suggest that glandular NO production is a prerequisite for the autonomic nervous modulation of endometrial secretion in the guinea pig and that NO may play a role in the implantation time.
Mörlin
B
B
Department of Woman and Child Health, Division of Obstetrics and Gynecology, Karolinska University Hospital, Solna, Sweden. birgitta.morlin@kus.se
Andersson
E
E
Byström
B
B
Hammarström
M
M
D000818:Animals; D001120:Arginine / Q000494:pharmacology; D002217:Carbachol / Q000494:pharmacology; D050260:Carbohydrate Metabolism; D018679:Cholinergic Agonists / Q000494:pharmacology; D010064:Embryo Implantation / Q000502:physiology*; D004717:Endometrium / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D019335:Nitroarginine / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D012313:RNA / Q000032:analysis; D011976:Receptors, Muscarinic / Q000502:physiology; D015290:Second Messenger Systems / Q000502:physiology*; D013997:Time Factors
D018679:Cholinergic Agonists; D004791:Enzyme Inhibitors; D011976:Receptors, Muscarinic; D019335:Nitroarginine; D009569:Nitric Oxide; D012313:RNA; D002217:Carbachol; D001120:Arginine; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester