Expression of endothelial and inducible nitric oxide synthases is modulated in the endometrium of cyclic and early pregnant mares

2004 ◽  
Vol 16 (7) ◽  
pp. 689 ◽  
Author(s):  
H. Welter ◽  
H. Bollwein ◽  
F. Weber ◽  
S. Rohr ◽  
R. Einspanier

The expression of the endothelial and inducible nitric oxide synthases (eNOS and iNOS, respectively) was examined in the endometrium of cyclic and pregnant mares by real-time polymerase chain reaction and immunohistology. The concentration of eNOS mRNA varied throughout the oestrous cycle, with significantly higher transcripts on Day 5 of the oestrous cycle (P < 0.05), whereas iNOS transcription did not change significantly over time (P > 0.05). In early pregnant mares both eNOS and iNOS mRNA increased between Days 12 and 15 (P < 0.05). In cyclic mares, eNOS protein was detected immunocytochemically in endometrial epithelia, the basement membrane, the endothelial layer and smooth muscle cells of the vasculature. Using immunocytochemical methods, iNOS protein was undetectable in the endometrium of cyclic mares but could be demonstrated in pregnant mares. Endometrial epithelia of pregnant mares were immunopositive for both proteins with a more intense labelling for iNOS. Thus, the present study describes for the first time the modulation and spatial distribution of eNOS and iNOS expression during the oestrous cycle and early pregnancy, suggesting that ovarian steroids are differently involved in the regulation of each NOS. Localisation of eNOS protein in endometrial epithelia and various vascular components indicates that this isoform may be involved in the regulation of endometrial cyclicity. The presence and increase of both forms of NOS during early gestation suggest a role for them in the control of endometrial vascular bed and glandular activity to provide a suitable microenvironment for successful pregnancy.

2001 ◽  
Vol 281 (3) ◽  
pp. C849-C856 ◽  
Author(s):  
Wen-Ning Qi ◽  
Zuo-Qin Yan ◽  
Peter G. Whang ◽  
Qi Zhou ◽  
Long-En Chen ◽  
...  

This study examined mRNA and protein expressions of neuronal (nNOS), inducible (iNOS), and endothelial nitric oxide synthases (eNOS) in peripheral nerve after ischemia-reperfusion (I/R). Sixty-six rats were divided into the ischemia only and I/R groups. One sciatic nerve of each animal was used as the experimental side and the opposite untreated nerve as the control. mRNA levels in the nerve were quantitatively measured by competitive PCR, and protein was determined by Western blotting and immunohistochemical staining. The results showed that, after ischemia (2 h), both nNOS and eNOS protein expressions decreased. After I/R (2 h of ischemia followed by 3 h of reperfusion), expression of both nNOS and eNOS mRNA and protein decreased further. In contrast, iNOS mRNA significantly increased after ischemia and was further upregulated (14-fold) after I/R, while iNOS protein was not detected. The results reveal the dynamic expression of individual NOS isoforms during the course of I/R injury. An understanding of this modulation on a cellular and molecular level may lead to understanding the mechanisms of I/R injury and to methods of ameliorating peripheral nerve injury.


2006 ◽  
Vol 188 (2) ◽  
pp. 205-213 ◽  
Author(s):  
S E Ulbrich ◽  
S Rehfeld ◽  
S Bauersachs ◽  
E Wolf ◽  
R Rottmayer ◽  
...  

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-17β 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-17β. The region-specific modulated expression of eNOS and iNOS provides evidence for an involvement of endogenously produced NO in the regulation of oviductal functions.


1998 ◽  
Vol 274 (6) ◽  
pp. H2035-H2045 ◽  
Author(s):  
Elena Galea ◽  
Eugene V. Golanov ◽  
Douglas L. Feinstein ◽  
Keith A. Kobylarz ◽  
Sara B. Glickstein ◽  
...  

A focal infarction produced by occlusion of the middle cerebral artery (MCAO) in spontaneously hypertensive rats induced expression of inducible nitric oxide synthase (iNOS) mRNA, measured by competitive reverse transcription-polymerase chain reaction. The mRNA appeared simultaneously in the ischemic core and penumbra at 8 h, peaked between 14 and 24 h, and disappeared by 48 h. At 24 h, inducible nitric oxide synthase (iNOS)-like immunoreactivity was present in the endothelium of cerebral microvessels and in scattered cells, probably representing leukocytes or activated microglia. Electrical stimulation of the cerebellar fastigial nucleus (FN) for 1 h, 48 h before MCAO, reduced infarct volumes by 45% by decreasing cellular death in the ischemic penumbra. It also reduced by >90% the expression of iNOS mRNA and protein in the penumbra, but not core, and decreased by 44% the iNOS enzyme activity. We conclude that excitation of neuronal networks represented in the cerebellum elicits a conditioned central neurogenic neuroprotection associated with the downregulation of iNOS mRNA and protein. This neuroimmune interaction may, by blocking the expression of iNOS, contribute to neuroprotection.


1995 ◽  
Vol 268 (4) ◽  
pp. F770-F777 ◽  
Author(s):  
M. G. Mohaupt ◽  
J. Schwobel ◽  
J. L. Elzie ◽  
G. S. Kannan ◽  
B. C. Kone

The effects of lipopolysaccharide (LPS) and/or inflammatory cytokines on the expression of inducible nitric oxide synthase (iNOS) were studied in mIMCD-3 cells, derived from the murine inner medullary collecting duct. Under basal conditions, the production of nitrite, a stable metabolite of NO, was negligible; however, incubation with tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IF-gamma) for 24 h resulted in a 12-fold increase in nitrite synthesis and the appearance of abundant iNOS mRNA and protein. The induction of nitrite production and iNOS mRNA was time dependent, requiring approximately 8 h for expression of significant levels of nitrite or iNOS mRNA. Coincubation with the transcription inhibitor actinomycin D or the translation inhibitor cycloheximide prevented the cytokine induction of iNOS mRNA and NO production, indicating that synthesis of intermediary proteins stimulated transcription of the iNOS gene. Nuclear run-on transcription demonstrated that the iNOS gene was transcriptionally inactive under basal conditions, but was markedly induced by TNF-alpha and IF-gamma. These results indicate that inflammatory cytokines stimulate NO production in mIMCD-3 cells by activating iNOS gene transcription in a process that requires new protein synthesis.


2000 ◽  
Vol 279 (3) ◽  
pp. R951-R959 ◽  
Author(s):  
Motoyuki Iemitsu ◽  
Takashi Miyauchi ◽  
Seiji Maeda ◽  
Koichi Yuki ◽  
Tsutomu Kobayashi ◽  
...  

Cardiac myocytes produce nitric oxide (NO). We studied the effects of intense exercise on the expression of NO synthase (NOS) and the tissue level of nitrite (NO2 −)/nitrate (NO3 −) (i.e., NOx), which are stable end products of NO in the heart. Rats ran on a treadmill for 45 min. Immediately after this exercise, the heart was quickly removed. Control rats remained at rest during the same 45-min period. The mRNA level of endothelial NOS (eNOS) in the heart was markedly lower in the exercised rats than in the control rats. Western blot analysis confirmed downregulation of eNOS protein in the heart after exercise. Tissue NOx level in the heart was significantly lower in the exercised rats than in the control rats. The present study revealed for the first time that production of NO in the heart is decreased by intense exercise. Because NO attenuates positive inotropic and chronotropic responses to β1-adrenergic stimulation in the heart, the decrease in cardiac production of NO by intense exercise may contribute to the acceleration of increase in myocardial contractility and heart rate during intense exercise.


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