https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:39583 Wed 27 Jul 2022 10:45:46 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:35679 Wed 24 Jun 2020 09:57:41 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:38603 Chlamydia trachomatis infection is a primary cause of reproductive tract diseases including infertility. Previous studies showed that this infection alters physiological activities in mouse oviducts. Whether this occurs in the uterus and cervix has never been investigated. This study characterized the physiological activities of the uterine horn and the cervix in a Chlamydia muridarum (Cmu)-infected mouse model at three infection time points of 7, 14, and 21 days postinfection (dpi). Cmu infection significantly decreased contractile force of spontaneous contraction in the cervix (7 and 14 dpi; P < 0.001 and P < 0.05, respectively), but this effect was not observed in the uterine horn. The responses of the uterine horn and cervix to oxytocin were significantly altered by Cmu infection at 7 dpi (P < 0.0001), but such responses were attenuated at 14 and 21 dpi. Cmu infection increased contractile force to prostaglandin (PGF2_α) by 53–83% in the uterine horn. This corresponded with the increased messenger ribonucleic acid (mRNA) expression of Ptgfr that encodes for its receptor. However, Cmu infection did not affect contractions of the uterine horn and cervix to PGE₂ and histamine. The mRNA expression of Otr and Ptger4 was inversely correlated with the mRNA expression of ll1b, ll6 in the uterine horn of Cmu-inoculated mice (P < 0.01 to P < 0.001), suggesting that the changes in the Otr and Ptger4mRNA expression might be linked to the changes in inflammatory cytokines. Lastly, this study also showed a novel physiological finding of the differential response to PGE₂ in mouse uterine horn and cervix.]]> Wed 17 Nov 2021 15:27:35 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:16822 2+ release from sarcoplasmic/endoplasmic reticulum Ca²⁺-ATPase (SERCA) -dependent intracellular Ca²⁺ stores; and 3) c-Kit and/or vimentin immunoreactive ICs have a role in pacemaking. Methodology/Principal Findings: Vaginal and cervical contractions were measured in vitro, as was the distribution of c-Kit and vimentin positive interstitial cells (ICs). Cervical smooth muscle was spontaneously active in estrus and metestrus but quiescent during proestrus and diestrus. Vaginal smooth muscle was normally quiescent but exhibited phasic contractions in the presence of oxytocin or the K⁺ channel blocker tetraethylammonium (TEA) chloride. Spontaneous contractions in the cervix and TEA-induced phasic contractions in the vagina persisted in the presence of cyclopiazonic acid (CPA), a blocker of the SERCA that refills intracellular SR Ca²⁺ stores, but were inhibited in low Ca²⁺ solution or in the presence of nifedipine, an inhibitor of L-type Ca²⁺channels. ICs were found in small numbers in the mouse cervix but not in the vagina. Conclusions/Significance: Cervical smooth muscle strips taken from mice in estrus, metestrus or late pregnancy were generally spontaneously active. Vaginal smooth muscle strips were normally quiescent but could be induced to exhibit phasic contractions independent on phase of the estrus cycle or late pregnancy. Spontaneous cervical or TEA-induced vaginal phasic contractions were not mediated by ICs or intracellular Ca²⁺ stores. Given that vaginal smooth muscle is normally quiescent then it is likely that increases in hormones such as oxytocin, as might occur through sexual stimulation, enhance the effectiveness of such pacemaking until phasic contractile activity emerges.]]> Wed 11 Apr 2018 13:40:08 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:2353 Sat 24 Mar 2018 08:27:55 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:13727 Sat 24 Mar 2018 08:22:56 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:12328 2+ concentration ([Ca²⁺]_i), through enhancing extracellular Ca²⁺ entry and Ca²⁺ release from the sarcoplasmic reticulum, processes that are intimately linked with mitochondria. This study examined the effects of oxytocin on mitochondrial function. This was achieved by measuring the ratiometric JC-1 fluorescence signal in isolated myometrial cells, which provides a relative measure of the mitochondrial membrane potential (ψ_m), and also by loading the cells with Oregon Green BAPTA-AM to examine changes in [Ca²⁺]_i. Oxytocin (1 nm) depolarized the ψ_m to 73.8 ± 3.7% of the control value (P < 0.05; perfused for 11 min) and also caused a transient increase in [Ca²⁺]_i. The depolarization of mitochondrial membrane potential was effectively reversed by 2-aminoethoxydiphenyl borate, nifedipine, Ca²⁺-free solution or oligomycin, with the ratiometric JC-1 fluorescence signal becoming no different from the control value in all cases (i.e. P > 0.05). The reduction in ψ_m is likely to occur at least in part through the oxytocin-induced increase in [Ca²⁺]_i, causing enhanced mitochondrial uptake of Ca²⁺ and resultant dissipation of the mitochondrial electrochemical gradient. ATP synthase is also stimulated, which would further contribute to a decrease in ψ_m.]]> Sat 24 Mar 2018 08:11:37 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:20986 Sat 24 Mar 2018 07:50:41 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:32313 Mon 23 Sep 2019 12:40:43 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:32099 Mon 23 Sep 2019 11:17:25 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:37778 Mon 19 Apr 2021 10:43:58 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:46859 Mon 05 Dec 2022 08:19:29 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:37785 2 = 0.32, p = 0.021) at baseline. Oxytocin levels were higher, and cholecystokinin levels lower, in food addicted (n = 6) vs. non-food addicted females (p = 0.015 and p<0.001, respectively). There were no significant changes (p>0.05) in plasma oxytocin levels in response to either healthy or hyperpalatable food images. Given that endogenous oxytocin administration tends to suppress eating behaviour; these data indicate that oxytocin receptor desensitization or oxytocin resistance may be important factors in the pathogenesis of obesity and food addiction. However, further studies in larger samples are needed to determine if peripheral oxytocin is responsive to visual food cues.]]> Fri 23 Apr 2021 14:41:22 AEST ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:37784  0.05) through altered diet or behaviors (neutral effect); in contrast, significant (P < 0.05) differences (increases and decreases) were identified in clinical samples. Exogenous oxytocin studies (n = 13) found reduced indices of food intake (positive effect) in clinical and nonclinical samples. Conclusions: Overall, few studies included comprehensive investigation of dietary intakes through the use of validated assessment tools. Dietary intake and behaviors appear to have some influence on oxytocin, with more pronounced effects found with exogenously administered oxytocin.]]> Fri 23 Apr 2021 14:34:22 AEST ]]>