Session - Respiratory & Critical Care Medicine: no. S-RC-1published_or_final_versio

Chan, S

Fung, PCW

Ho, JCM

Ip, S

Lam, WK

Leung, RYH

Shum, IHY

Tsang, KWT

Wang, J

Zheng, L

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Title Nitric oxide (NO) levels in exhaled air, sputum, serum, saliva,and urine of bronchiectasis subjects: a comparision studyAuthor(s) Tsang, KWT; Chan, S; Fung, PCW; Zheng, L; Shum, IHY; Leung,RYH; Ho, JCM; Ip, S; Wang, J; Lam, WKCitation The 5th Medical Research Conference, Hong Kong, China,January 2000, v. 22 n. Supp 2, p. 54Issued Date 2000URL http://hdl.handle.net/10722/46801Rights Creative Commons: Attribution 3.0 Hong Kong LicenseS-N-6EFFECTS OF ESTROGEN ON CATECHOL-O-METHYLTRANSFERASE (COMT)Jiang Hong , Feng Zhe-huif, David Ramsdenf, Ho Shu-Leongf Division of Neurology, University Dept ofMedicine, Queen Mary Hospital, The University of Hong Kong, and Dept of Medicine, University ofBirnimgham$, UKCOMT is a crucial enzyme in dopamine and levodopa metabolism. COMT inhibitors are effective adjuncttherapy to Ldopa in Parkinson's Disease (PD). We have previously shown that 17(3-estradiol can downregulatehuman COMT gene transcription via its promoter regions using CAT reporter activity assays. Purified antiserumcontaining human COMT antibodies developed using specifically designed oligopeptides injected into sheep,was used to carry out Western Blots. We showed that COMT protein expression was decreased in a dose-dependent manner in MCF-7 cells after exposure to physiologic concentrations of 17p-estradiol for 72 hours.A specific estrogen receptor antagonist (ICI 182780) blocked this estrogenic effect. Using a radioenzymaticassay, we further showed that COMT activity was similarly affected. We investigated the underlying mechanismof these estrogenic effects by characterizing the function of estrogen response elements (EREs) in the proximalpromoter region by exploring their DNA-protein binding activities. Our gelshift assays showed that nuclearproteins from MCF-7 cells could specifically bind to our ERE1 or ERE2 probe. Preincubation of the nuclearprotein with excess non-labeled probes or estrogen receptor (a and p) antibodies competitively inhibited thisbinding. Using semiquantitative gelshifts, we also showed that 17p-estradiol can increase estrogen receptor(ER)-ERE binding activity in a dose-dependent manner. We conclude that 17p-estradiol can decrease COMTprotein expression and activity in a dose-dependent manner through estrogen receptors. These estrogeniceffects were associated with a dose-dependent increase in ER-ERE binding. Our results can explain theworsening of motor control during menstruation in premenopausal PD patients, and after withdrawal of hormonereplacement therapy in postmenopausal PD patients. It also suggests that estrogen can be a useful adjuncttherapy for PD in postmenopausal women.S-RC-1NITRIC OXIDE (NO) LEVELS IN EXHALED AIR, SPUTUM, SERUM, SALIVA AND URINE OFBRONCHIECTASIS SUBJECTS: A COMPARISON STUDYKWT Tsang. S Chan, P Fung, L Zheng, IHY Shum, R Leung, JCM Ho, S Ip, J Wang, WK Lam. UniversityDept of Medicine, The University of Hong Kong, Hong Kong SAR.Endogenous NO has received tremendous attention in the last few years and promises to be a final commonpath for the pathogenesis of many respiratory, renal, neurological and liver diseases. Exhaled NO is increasedin asthma but decreased in cystic fibrosis, cigarette smoking and HIV infection. However, the levels of NO inother body fluids including saliva, urine and serum have not been evaluated and compared with exhaled NO.We have, therefore, determined their correlation in a cohort of xx patients with stable bronchiectasis (xxF;mean age±SD 58.2± 14.lyrs; FEV, 72.5±28.9% pred; and FVC 81.5±23.3% pred). Exhaled NO was measuredby using a Sievers NO Analyser280 at a steady exhaled pressure of 20 torr with chemiluminescence. Bodyfluids NO contents were analyzed by measuring the total nitrate products, after de-proteinisation, using thesame package. There were significant differences (p<0.05) between the exhaled NO (25.5±21.8 units) levelscompared with the simultaneous levels in serum (127.4±94.3), sputum sol (1167.6± 1400), urine(2559.6+4083.4), and saliva (3085.9± 3839.7). There no correlation between exhaled NO levels with those inthe aforementioned bodily fluids. However, there was a positive correlation between the levels of NO betweenserum and sputum (r=0.51, p=0.0001), urine (0.56, 0.0001), and saliva (0.48, 0.0001). There was also aweaker correlation between the level of NO in sputum and urine (0.35, 0.003). Our results show, for the firsttime, the relationship between simultaneous levels of NO in exhaled air and other bodily fluids and should helpresearchers in future studies. (Supported by a CRCG Grant of the University of Hong Kong)- 54 -

Nitric oxide (NO) levels in exhaled air, sputum, serum, saliva, and urine of bronchiectasis subjects: a comparision study

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Nitric oxide (NO) levels in exhaled air, sputum, serum, saliva, and urine of bronchiectasis subjects: a comparision study

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