scholarly journals Reduced nitric oxide synthase and cyclo-oxygenase activity in the uterus of non-obese diabetic mice

Reproduction ◽  
2006 ◽  
Vol 132 (6) ◽  
pp. 931-938 ◽  
Author(s):  
Valeria Roca ◽  
Luciana Larocca ◽  
Mario Calafat ◽  
Julieta Aisemberg ◽  
Roberto Meiss ◽  
...  

A functional interaction between progesterone, Th2 cytokines and a suitable balance between nitric oxide and prostaglandins in the uterus is considered to have a major role in the success of embryo implantation and pregnancy. Non-obese diabetic (NOD) mice offer a suitable model to study the modulatory role of Th1 cytokines on uterus signalling and function, since at the prediabetic stage they develop a spontaneous Th1 autoimmune response against exocrine glands similar to Sjögren’s syndrome. Vasoactive intestinal peptide (VIP) is a vasoactive neuro- and immunopeptide that promotes Th2 profiles and contributes to the smooth muscle relaxation and vasodilation. The aim of the present study was to investigate the activities of nitric oxide synthase and cyclo-oxygenase and the effect of VIP in the uterus of NOD mice with an emerging Th1 cytokine response. We present evidence of a reduced basal and VIP-stimulated activity of both enzymes in the uterus of NOD mice compared with normal BALB/c mice in proestrus. An altered functional interaction between both enzymes is also present in NOD mice at the time when increased levels of serum interleukin (IL)-12 and tumour necrosis factor-α but not interferon (IFN)-γ or IL-10 were detected. We conclude that signalling alterations in uteri of NOD mice are simultaneous to the onset of a systemic Th1 cytokine response.

1994 ◽  
Vol 267 (1) ◽  
pp. R228-R235 ◽  
Author(s):  
C. Iadecola ◽  
F. Zhang ◽  
X. Xu

We sought to determine whether the attenuation of the hypercapnic cerebrovasodilation associated with inhibition of nitric oxide synthase (NOS) can be reversed by exogenous NO. Rats were anesthetized (halothane) and ventilated. Neocortical cerebral blood flow (CBF) was monitored by a laser-Doppler probe. The NOS inhibitor N omega-nitro-L-arginine methyl ester (L-NAME; 40 mg/kg iv) reduced resting CBF [-36 +/- 5% (SE); P < 0.01, analysis of variance] and attenuated the increase in CBF elicited by hypercapnia (partial pressure of CO2 = 50-60 mmHg) by 66% (P < 0.01). L-NAME reduced forebrain NOS catalytic activity by 64 +/- 3% (n = 10; P < 0.001). After L-NAME, intracarotid infusion of the NO donor 3-morpholinosydnonimine (SIN-1; n = 6) increased resting CBF and reestablished the CBF increase elicited by hypercapnia (P > 0.05 from before L-NAME). Similarly, infusion of the guanosine 3',5'-cyclic monophosphate (cGMP) analogue 8-bromo-cGMP (n = 6) reversed the L-NAME-induced attenuation of the hypercapnic cerebrovasodilation. The NO-independent vasodilator papaverine (n = 6) increased resting CBF but did not reverse the attenuation of the CO2 response. SIN-1 did not affect the attenuation of the CO2 response induced by indomethacin (n = 6). The observation that NO donors reverse the L-NAME-induced attenuation of the CO2 response suggests that a basal level of NO is required for the vasodilation to occur. The findings are consistent with the hypothesis that NO is not the final mediator of smooth muscle relaxation in hypercapnia.(ABSTRACT TRUNCATED AT 250 WORDS)


2004 ◽  
Vol 72 (4) ◽  
pp. 2400-2404 ◽  
Author(s):  
Charles A. Scanga ◽  
Andre Bafica ◽  
Carl G. Feng ◽  
Allen W. Cheever ◽  
Sara Hieny ◽  
...  

ABSTRACT Mycobacterium tuberculosis possesses agonists for several Toll-like receptors (TLRs), yet mice with single TLR deletions are resistant to acute tuberculosis. MyD88−/− mice were used to examine whether TLRs play any role in protection against aerogenic M. tuberculosis H37Rv infection. MyD88−/− mice failed to control mycobacterial replication and rapidly succumbed. Moreover, expressions of interleukin 12, tumor necrosis factor alpha, gamma interferon, and nitric oxide synthase 2 were markedly decreased in the knockout animals. These results argue that resistance to M. tuberculosis must depend on MyD88-dependent signals mediated by an as-yet-undetermined TLR or a combination of TLRs.


1998 ◽  
Vol 66 (3) ◽  
pp. 1265-1269 ◽  
Author(s):  
Linda L. Perry ◽  
Karen Feilzer ◽  
Harlan D. Caldwell

ABSTRACT Female mice bearing targeted mutations in the interleukin-6 or inducible nitric oxide synthase locus mounted effective immune responses following vaginal infection with Chlamydia trachomatis. Chlamydial clearance rates, local Th1 cytokine production, and host antibody responses were similar to those of immunocompetent control mice. Therefore, neither gene product appears to be critical for the resolution of chlamydial infections of the urogenital epithelium.


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