Guest guest Posted November 9, 2006 Report Share Posted November 9, 2006 Jpn J Pharmacol. <javascript:AL_get(this, 'jour', 'Jpn J Pharmacol.');> 1995 Apr;67(4):271-8. Related Articles, <http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?itool=pubmed_Abstract & db=pubmed & c\ md=Display & dopt=pubmed_pubmed & from_uid=7650862 & itool=ExternalSearch> Links <javascript:PopUpMenu2_Set(Menu7650862);> Click here to read <http://www.ncbi.nlm.nih.gov/entrez/utils/fref.fcgi?itool=Abstract-def & PrId=3580\ & uid=7650862 & db=PubMed & url=http://joi.jlc.jst.go.jp/JST.Journalarchive/jphs1951/\ 67.271?from=PubMed> *Residence time of polaprezinc (zinc L-carnosine complex) in the rat stomach and adhesiveness to ulcerous sites.* *Furuta S* <http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed & cmd=Search & itool=pubmed\ _Abstract & term=%22Furuta+S%22%5BAuthor%5D>, *Toyama S* <http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed & cmd=Search & itool=pubmed\ _Abstract & term=%22Toyama+S%22%5BAuthor%5D>, *Miwa M* <http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed & cmd=Search & itool=pubmed\ _Abstract & term=%22Miwa+M%22%5BAuthor%5D>, *Itabashi T* <http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed & cmd=Search & itool=pubmed\ _Abstract & term=%22Itabashi+T%22%5BAuthor%5D>, *Sano H* <http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed & cmd=Search & itool=pubmed\ _Abstract & term=%22Sano+H%22%5BAuthor%5D>, *Yoneta T* <http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed & cmd=Search & itool=pubmed\ _Abstract & term=%22Yoneta+T%22%5BAuthor%5D>. Central Research Laboratories, Zeria Pharmaceutical Co., Ltd., Saitama, Japan. Polaprezinc, an insoluble zinc complex of L-carnosine, exhibits anti-ulcer effects by acting directly on mucosal lesions. The disposition of polaprezinc in the stomach was studied to clarify the usefulness of its structure as an insoluble complex. The time courses of 14C-radioactivity in the gastric contents and gastric tissues were parallel to those of 65Zn after oral administration of a mixture of 14C-polaprezinc and 65Zn-polaprezinc (14C-, 65Zn-polaprezinc) to rats. The gastric contents of 14C-polaprezinc and 65Zn-polaprezinc were greater than those of 14C-L-carnosine and 65ZnSO4. Mean residence times (MRT) of 14C-polaprezinc and 65Zn-polaprezinc in the stomach were almost the same (ca. 2 hr), and they were double those of 14C-L-carnosine and 65ZnSO4. In gastric tissues, the area under the concentration curves (AUC0-8 hr) of 14C-polaprezinc and 65Zn-polaprezinc were 1.7 times greater than those of 14C-L-carnosine and 65ZnSO4, respectively. After administration of 14C-, 65Zn-polaprezinc to rats with acetic acid-induced ulcers, 14C and 65Zn-radioactivities in the ulcerous sites were very similar and greater than those of 14C-, 65Zn-polaprezinc dissolved in acid. In conclusion, polaprezinc is retained in the stomach longer and adheres to the ulcerous sites more than zinc or L-carnosine. The characteristics of this compound may arise from its insolubility and contribute to its strong pharmacological action. Vol. 291, Issue 1, 345-352, October 1999 *Polaprezinc Down-Regulates Proinflammatory Cytokine-Induced Nuclear Factor-kappa B Activiation and Interleukin-8 Expression in Gastric Epithelial Cells^1 * * Tadahito Shimada, Naomi Watanabe, Yukio Ohtsuka, Motoya Endoh, Kazuo Kojima, Hideyuki Hiraishi and Akira Terano * Second Department of Internal Medicine, Dokkyo University School of Medicine, Mibu, Tochigi, Japan Gastric epithelial chemokine response is a primary factor in the induction of gastric inflammation associated with /Helicobacter^ pylori/ infection. Because sustained inflammation is a risk for^ gastric mucosal damage, agents that down-regulate inflammatory^ responses may be of therapeutic significance. We examined the^ effect of polaprezinc, a potent antiulcer agent, on proinflammatory^ cytokine-induced interleukin (IL)-8 expression in gastric epithelial^ cells. Because IL-8 expression is regulated by the transcription^ factor nuclear factor-kappa B (NF-kappa , we also examined the effect^ of polaprezinc on NF-kappa B activity. MKN28 cells were used as a model^ of gastric epithelial cells. Secreted IL-8 was quantified by IL-8^ specific enzyme-linked immunosorbent assay, and IL-8 mRNA expression^ was examined by Northern blot analysis. NF-kappa B activity was analyzed^ by electrophoretic mobility shift assay. Western blot analysis^ with anti-phospho-Ikappa B-alpha antibody was performed to assess Ikappa B-alpha ^ phosphorylation. Polaprezinc-suppressed IL-8 secretion induced^ by tumor necrosis factor alpha (TNF-alpha ) or IL-1beta in a dose-dependent^ manner. IL-8 mRNA expression also was inhibited by polaprezinc.^ NF-kappa B activation in response to TNF-alpha , IL-1beta , phorbol ester, and^ H_2 O_2 was down-regulated by polaprezinc. Western blot analysis^ showed inhibition of TNF-alpha -induced Ikappa B-alpha phosphorylation in the^ presence of polaprezinc. Collectively, these results suggest that^ polaprezinc is a novel type of anti-inflammatory agent that down-regulates^ inflammatory responses of gastric mucosal^ cells. Aliment Pharmacol Ther. <javascript:AL_get(this, 'jour', 'Aliment Pharmacol Ther.');> 1999 Feb;13(2):261-9. Related Articles, <http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?itool=pubmed_Abstract & db=pubmed & c\ md=Display & dopt=pubmed_pubmed & from_uid=10102958 & itool=ExternalSearch> Links <javascript:PopUpMenu2_Set(Menu10102958);> Click here to read <http://www.ncbi.nlm.nih.gov/entrez/utils/fref.fcgi?itool=Abstract-def & PrId=3046\ & uid=10102958 & db=PubMed & url=http://www.blackwell-synergy.com/openurl?genre=artic\ le & sid=nlm:pubmed & issn=0269-2813 & date=1999 & volume=13 & issue=2 & spage=261> *Polaprezinc protects gastric mucosal cells from noxious agents through antioxidant properties in vitro.* *Hiraishi H* <http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed & cmd=Search & itool=pubmed\ _Abstract & term=%22Hiraishi+H%22%5BAuthor%5D>, *Sasai T* <http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed & cmd=Search & itool=pubmed\ _Abstract & term=%22Sasai+T%22%5BAuthor%5D>, *Oinuma T* <http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed & cmd=Search & itool=pubmed\ _Abstract & term=%22Oinuma+T%22%5BAuthor%5D>, *Shimada T* <http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed & cmd=Search & itool=pubmed\ _Abstract & term=%22Shimada+T%22%5BAuthor%5D>, *Sugaya H* <http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed & cmd=Search & itool=pubmed\ _Abstract & term=%22Sugaya+H%22%5BAuthor%5D>, *Terano A* <http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed & cmd=Search & itool=pubmed\ _Abstract & term=%22Terano+A%22%5BAuthor%5D>. Second Department of Internal Medicine, Dokkyo University School of Medicine, Mibu, Tochigi, Japan. BACKGROUND: Polaprezinc has been shown to exert an anti-oxidant property in a tube experiment, protect gastric mucosa from experimental ulcerations in vivo, and accelerate the healing of gastric ulcer in humans. AIM: To examine a possible protective effect of polaprezinc on oxidant-mediated injury in primary monolayer cultures of rat gastric fundic mucosa. METHODS: Cytotoxicity was quantified by measuring 51Cr release. Whether or not polaprezinc exerts an antioxidant property was investigated by determining the effect of this agent on hydrogen peroxide (H2O2)-induced injury. The effects of polaprezinc on superoxide (O2-. ) generation as well as on ethanol (EtOH)-induced injury were also examined. Generation of O2-. was assessed by the reduction in cytochrome c. RESULTS: H2O2 caused a time- and dose-dependent increase in 51Cr release. The dose-response curve of 51Cr release by H2O2 shifted to the right in the presence of polaprezinc. Polaprezinc, at submillimolar concentrations, prevented H2O2-induced 51Cr release. EtOH also caused a dose-dependent increase in 51Cr release, which was prevented by the addition of polaprezinc. The incubation of cells with EtOH caused an increase in cytochrome c reduction, as the concentrations of EtOH increased. Polaprezinc inhibited EtOH-induced cytochrome c reduction. Protection by polaprezinc was microscopically associated with the prevention of monolayer disruption. CONCLUSIONS: Polaprezinc is antioxidative and directly protects gastric mucosal cells from noxious agents through its antioxidant properties in vitro. This finding may provide the theoretical basis for the usage of an antiulcer drug with antioxidant properties for the treatment of gastric inflammation, such as that induced by ethanol. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You are posting as a guest. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.