Please wait, while we are loading the content...
Please wait, while we are loading the content...
| Content Provider | World Health Organization (WHO)-Global Index Medicus |
|---|---|
| Author | Hu, W. M. Man, R. Y. |
| Description | Author Affiliation: Hu WM ( Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Manitoba, Winnipeg, Canada.) |
| Abstract | 1. The coronary vascular effects of platelet-activating factor (PAF) have been intensively studied and it has been proposed that they are mediated by the release of vasoactive substances. In this study, a cascade perfusion model using two rat perfused hearts was developed to investigate the properties of PAF-released vasoactive substances and the interplay of these substances. The properties of the vasoactive substances after an injection of PAF (100 pmol) in the rat perfused heart were examined by collecting the effluent from the first heart for the perfusion of a second (recipient) heart. The presence of vasoconstrictor substances in the effluent was characterized by an increase in the perfusion pressure of the recipient heart. 2. Previous exposure of the recipient heart of PAF (100 pmol) abolished the response of the heart to subsequent administration of PAF, but did not affect the response of the recipient heart to the effluent. This suggested that the coronary vasoconstrictor response of the recipient heart was not due to the presence of PAF in the effluent but to other vasoactive substances. 3. Pretreatment of the recipient heart with the leukotriene receptor antagonist, L-649,923 (5 microM), partially reduced the vasoconstrictor effect of the effluent. Pretreatment of the first heart with indomethacin (2.8 microM) also partially reduced the vasoconstrictor effect of the effluent. The combination of indomethacin pretreatment of the first heart and L-649,923 pretreatment of the recipient heart completely abolished the vasoconstrictor effect of the effluent suggesting that both prostaglandins and leukotrienes are involved in the vasoconstrictor effect of the effluent. 4. Pretreatment of both hearts with L-649,923 or the first heart with the leukotriene synthesis inhibitor (MK-886, 10 microM) completely abolished the vasoconstrictor effect of the effluent. This suggested that the indomethacin sensitive vasoconstrictor component of the effluent might be regulated by leukotrienes in the first heart. However, infusion of leukotrienes (LTB4, LTC4 and LTD4) to the first heart did not reproduce this vasoconstrictor component of the effluent in the recipient heart.5. In conclusion, our study demonstrated through the use of a leukotriene receptor antagonist, a leukotriene synthesis inhibitor and a cyclo-oxygenase inhibitor that the vasoconstrictor effect of the effluent of the rat perfused heart after an injection of PAF is mediated by leukotrienes and prostaglandins. The ability of leukotriene receptor blockade and inhibition of leukotriene synthesis to mimic the effect of indomethacin indicates that the production and/or release of cyclo-oxygenase products in the effluent by PAF can be modulated by leukotrienes. The inability of exogenously applied leukotrienes to modulate the production and/or the release of cyclo-oxygenase products in the effluent suggests that the PAF-induced production of prostaglandins may be mediated by intracellular leukotrienes or at sites not accessible to exogenously applied leukotrienes. |
| ISSN | 00071188 |
| e-ISSN | 14765381 |
| Journal | British Journal of Pharmacology |
| Issue Number | 4 |
| Volume Number | 104 |
| Language | English |
| Publisher | Wiley Online Library(on behalf of The British Pharmacological Society) |
| Publisher Date | 1991-12-01 |
| Publisher Place | Great Britain (UK) |
| Access Restriction | Open |
| Subject Keyword | Arachidonic Acids Physiology Coronary Circulation Heart Drug Effects Platelet Activating Factor Pharmacology Animals Blood Gas Analysis Cyclooxygenase Inhibitors In Vitro Techniques Indoles Indomethacin Leukotriene Antagonists Perfusion Phenylbutyrates Antagonists & Inhibitors Potassium Blood Rats, Inbred Strains Sodium Vasoconstriction Research Support, Non-U.S. Gov't |
| Content Type | Text |
| Resource Type | Article |
| Subject | Pharmacology |
National Digital Library of India (NDLI) is a virtual repository of learning resources which is not just a repository with search/browse facilities but provides a host of services for the learner community. It is sponsored and mentored by Ministry of Education, Government of India, through its National Mission on Education through Information and Communication Technology (NMEICT). Filtered and federated searching is employed to facilitate focused searching so that learners can find the right resource with least effort and in minimum time. NDLI provides user group-specific services such as Examination Preparatory for School and College students and job aspirants. Services for Researchers and general learners are also provided. NDLI is designed to hold content of any language and provides interface support for 10 most widely used Indian languages. It is built to provide support for all academic levels including researchers and life-long learners, all disciplines, all popular forms of access devices and differently-abled learners. It is designed to enable people to learn and prepare from best practices from all over the world and to facilitate researchers to perform inter-linked exploration from multiple sources. It is developed, operated and maintained from Indian Institute of Technology Kharagpur.
Learn more about this project from here.
NDLI is a conglomeration of freely available or institutionally contributed or donated or publisher managed contents. Almost all these contents are hosted and accessed from respective sources. The responsibility for authenticity, relevance, completeness, accuracy, reliability and suitability of these contents rests with the respective organization and NDLI has no responsibility or liability for these. Every effort is made to keep the NDLI portal up and running smoothly unless there are some unavoidable technical issues.
Ministry of Education, through its National Mission on Education through Information and Communication Technology (NMEICT), has sponsored and funded the National Digital Library of India (NDLI) project.
| Sl. | Authority | Responsibilities | Communication Details |
|---|---|---|---|
| 1 | Ministry of Education (GoI), Department of Higher Education |
Sanctioning Authority | https://www.education.gov.in/ict-initiatives |
| 2 | Indian Institute of Technology Kharagpur | Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project | https://www.iitkgp.ac.in |
| 3 | National Digital Library of India Office, Indian Institute of Technology Kharagpur | The administrative and infrastructural headquarters of the project | Dr. B. Sutradhar bsutra@ndl.gov.in |
| 4 | Project PI / Joint PI | Principal Investigator and Joint Principal Investigators of the project |
Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon |
| 5 | Website/Portal (Helpdesk) | Queries regarding NDLI and its services | support@ndl.gov.in |
| 6 | Contents and Copyright Issues | Queries related to content curation and copyright issues | content@ndl.gov.in |
| 7 | National Digital Library of India Club (NDLI Club) | Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach | clubsupport@ndl.gov.in |
| 8 | Digital Preservation Centre (DPC) | Assistance with digitizing and archiving copyright-free printed books | dpc@ndl.gov.in |
| 9 | IDR Setup or Support | Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops | idr@ndl.gov.in |
|
Loading...
|