Region-specific expression of nitric oxide synthases in the bovine oviduct during the oestrous cycle and in vitro

Abstract

Nitric oxide synthases (NOS) account for the endogenous production of nitric oxide (NO), a small and permeable bioreactive molecule. NO is known to act as a paracrine mediator during various processes associated with female reproduction. In the present study, the mRNA expression of the endothelial (eNOS) and inducible (iNOS) NO synthases were examined in bovine oviduct epithelial cells (BOEC) during the oestrous cycle. In addition, eNOS and iNOS mRNA and protein were localised by in situ hybridisation and immunocytochemistry respectively. Furthermore, the effects of exogenously applied oestradiol-17 and progesterone on NOS mRNA regulation were studied in a suspension culture of BOEC. The eNOS mRNA abundance was low around ovulation (day 0) and increased significantly until pro-oestrus (day 18) in the ampulla. Immunoreactive protein of eNOS was detected predominantly in endothelial cells as well as in secretory oviduct epithelial cells at pro-oestrus. The iNOS mRNA concentration was significantly reduced in the isthmus at pro-oestrus (day 18) and oestrus (day 0) compared with persistently high levels in the ampulla. By in situ hybridisation, specific iNOS transcripts were additionally demonstrated in the oviduct epithelium. Immunoreactive iNOS protein was localised in secretory epithelial cells as well as in the lamina muscularis. The in vitro stimulation showed that both NOS were stimulated by progesterone, but not by oestradiol-17 . The region-specific modulated expression of eNOS and iNOS provides evidence for an involvement of endogenously produced NO in the regulation of oviductal functions.

Regulation of bovine oviductal NO synthesis by follicular steroids and prostaglandins

“…( Lapointe et al 2006, Ulbrich et al 2006. The present results suggest that prostaglandins (PGs) in follicular fluid as well as estradiol-17β in blood stream regulate NO synthesis in oviductal epithelial cells.…”

“…6). In addition, partial differences of NO synthases in cyclic epithelium of the oviduct (Ulbrich et al 2006) and whole layers containing stroma and smooth muscle of the oviduct (Fig. 1) suggest layer-specific control of NO synthesis in the oviductal milieu.…”

“…In the murine oviduct, the ampullary region has high ciliary activity, whereas the isthmus has strong muscular contraction and weak ciliary activity (Noreikat et al 2012) The expressions of genes for endothelins, PG synthases, and sex steroid receptors are also different among regions of the oviduct (Ulbrich et al 2003, Gauvreau et al 2010, Jeoung et al 2010, SaintDizier et al 2012. Similarly, NOS2 mRNA expression at the day of ovulation is higher in the ampulla than in the isthmus of the bovine oviduct (Ulbrich et al 2006). Thus, NO synthesis may be regulated differently in the ampulla and isthmus.…”

“…Nitric oxide synthases have three isoforms, neuronal NOS (nNOS), inducible NOS (NOS2), and endothelial NOS (NOS3) (Ulbrich et al 2006). Nitric oxide relaxes the oviductal smooth muscle for gamete/embryo transport (Rosselli et al 1994, Yilmaz et al 2012.…”

Altered Na⁺/K⁺-ATPase expression plays a role in rumen epithelium adaptation in sheep fed hay ad libitum or a mixed hay/concentrate diet

“…The abundance of mRNA for the ribosomal protein S18 (S18) and for the Na + /K + -ATPase α subunit was quantified by qRT-PCR using the iCycler and the iQ-SYBR green supermix (Bio-Rad Laboratories GmbH, Munich, Germany) as described previously Ulbrich et al, 2006). Briefly, 1 μl aliquots of each RT reaction (1/20 of total) were primed, in each 10 µl PCR, with gene-specific oligonucleotides (final concentration of 0.2µM) for S18 (gi 74268022: 5'-CTT AAA CAG ACA GAA GGA CGT GAA-3' and 5'-CCA CAC ATT ATT TCT TCT TGG ACA-3'; transcript size: 218 bp) and Na + /K + -ATPase α (gi 115305283: 5'-GAG ATT ACC CCC TTC CTG ATA TTT-3' and 5'-TGG ATC ATA CCA ATC TGT CCA TAG-3'; transcript size: 227 bp).…”