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 | Mironneau, C. Rakotoarisoa, L. Neuilly, G. Sayet, I. Mironneau, J. |
| Description | Author Affiliation: Sayet I ( Laboratoire de Physiologie Cellulaire et Pharmacologie Moléculaire, URA CNRS 1489, Université de Bordeaux II, France.) |
| Abstract | 1. In vascular smooth muscle, alpha 1-adrenoceptors have been classified recently into two or three subtypes. We examined which alpha 1-adrenoceptor subtypes are involved in the noradrenaline-induced contraction of rat portal vein smooth muscle. 2. Binding studies with [3H]-prazosin in membranes from equine portal vein smooth muscle revealed the presence of two distinct affinity binding sites. The high-affinity site for [3H]-prazosin was also identified in intact strips of rat portal vein. Prazosin, HV723 (alpha-ethyl-3,4,5-trimethoxy-alpha-(3-((2-(2-methoxyphenoxy)ethyl)-amin o)- propyl) benzene-acetonitrile fumarate), WB4101 (2-(2,6-dimethoxyphenoxyethyl)aminomethyl-1,4-benzodioxane), 5-methylurapidil, phentolamine and yohimbine antagonized [3H]-prazosin binding at both types of sites. Pretreatment with 50 microM chloroethylclonidine (CEC) eliminated the high-affinity sites for prazosin but had no effect on the low-affinity sites. 3. Noradrenaline produced a concentration-dependent contraction in the rat portal vein. Pretreatment with 50 microM CEC induced a slight rightward displacement of the concentration-response curve but the maximal contraction was not significantly affected suggesting that the CEC-sensitive alpha 1-adrenoceptors played a minor role in the noradrenaline-induced contraction. Prazosin, WB4101 and HV723 produced a concentration-dependent inhibition of noradrenaline-induced contractions. The inhibition curves were little affected by CEC-pretreatment and yielded a relative order of potency of WB4101 > prazosin > HV723. 4. In the presence of 0.1 microM isradipine to block voltage-dependent Ca2+ channels, the noradrenaline-induced contraction is due to release of Ca2+ ions from agonist-sensitive intracellular Ca2+ stores. Under these conditions, the noradrenaline-induced contraction was not significantly affected by pretreatment with 50 microM CEC but was inhibited by the antagonists mentioned above with affinities different from those in the absence of isradipine. The rank order of potency became HV723 > WB4101 > prazosin.5. The present results indicate the existence of two distinct o1-adrenoceptor subtypes in rat portal vein smooth muscle, which show high- and low-affinities respectively for each of prazosin, WB4101 andHV723 and correspond to alphalH- and alphalL-adrenoceptor subtypes. According to recent alpha1-adrenoceptor subclassifications, the alpha l H-adrenoceptor subtype which is sensitive to inactivation by CEC may correspond to the alpha1B-adrenoceptor subtype. The contraction induced by noradrenaline seems to be predominantly mediated through the alphalL-adrenoceptor subtypes which may include the alpha1N-adrenoceptor subtype, as recently proposed. |
| ISSN | 00071188 |
| e-ISSN | 14765381 |
| Journal | British Journal of Pharmacology |
| Issue Number | 1 |
| Volume Number | 110 |
| Language | English |
| Publisher | Wiley Online Library(on behalf of The British Pharmacological Society) |
| Publisher Date | 1993-09-01 |
| Publisher Place | Great Britain (UK) |
| Access Restriction | Open |
| Subject Keyword | Muscle, Smooth, Vascular Drug Effects Norepinephrine Pharmacology Receptors, Adrenergic, Alpha-1 Acetonitriles Adrenergic Alpha-Antagonists Alkylating Agents Animals Clonidine Analogs & Derivatives Dioxanes Horses In Vitro Techniques Isometric Contraction Kinetics Microsomes Metabolism Muscle Contraction Portal Vein Prazosin 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...
|