Linked Life Data

10198190

Source:http://linkedlifedata.com/resource/pubmed/id/10198190

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1999-7-8
pubmed:abstractText
The kappa-opioid receptor exerts a negative modulatory action on the beta-adrenoceptor and the action is blunted in adult spontaneously hypertensive rats (SHR). In order to determine whether the blunted negative modulation of the beta-adrenoceptor by the kappa-opioid receptor contributes to the development of hypertension, the electrically induced intracellular calcium ([Ca2+]i) transient was measured in single ventricular myocytes of SHR at 4, 6, 8 and 13-week-old and the age-matched Wistar Kyoto (WKY) rats. The electrically induced [Ca2+]i transients were augmented by norepinephrine (NE), a beta-adrenoceptor agonist, over four-fold in WKY rats of all ages studied and in SHR of 4 and 6 weeks of age. The enhancing effect of NE in 8- and 13-week-old SHR was, however, only approximately three-fold, significantly lower than the corresponding values in age-matched WKY rats. Similarly, the electrically induced [Ca2+]i transients were also augmented by forskolin, an activator of adenylate cyclase, by approximately two-fold in WKY rats of all ages and SHR aged 4 and 6 weeks. In SHR aged 8 and 13 weeks, the effect of forskolin was only 1.5-fold, significantly lower than the two-fold increase in the corresponding WKY rats. The enhancing effects of NE and forskolin were attenuated by U50,488H, a selective kappa-opioid agonist, by approximately 50 and 25%, respectively, in both types of rats of all ages studied, with the exception of 13-week-old rats. In rats of this age group, the attenuations by U50,488H on the enhancing effects of NE and forskolin were 17 and 9% in SHR, respectively, significantly less than the corresponding 54 and 29% in WKY. The fact that attenuation of U50,488H on the enhancing effects of NE and forskolin only occurs in 13-week-old SHR when hypertension has been fully developed indicates that the attenuated inhibitory modulation of kappa-opioid receptor stimulation does not contribute to the initiation of hypertension. Interestingly, the enhancing effects of NE and forskolin on the electrically induced [Ca2+]i transient was attenuated in SHR aged from 8 weeks when the blood pressure was rapidly increasing. The different time courses of altered responses to U50,488H, and NE and forskolin suggest that the attenuated negative modulation of kappa-receptor stimulation on the beta-adrenergic receptor is not due to the signal transduction pathway activated by beta-adrenergic stimulation. In 13-week-old SHR with the arterial blood pressure restored to normal by pharmacological manipulations, the blunted responses to NE, U50,488H and forskolin still occurred, indicating that the altered responses to activation of beta-adrenergic and kappa-opioid receptors and adenylate cyclase are not secondary to hypertension.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0022-2828
pubmed:author
pubmed:issnType
Print
pubmed:volume
31
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
597-605
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:10198190-3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-ben..., pubmed-meshheading:10198190-Adrenergic alpha-Agonists, pubmed-meshheading:10198190-Age Factors, pubmed-meshheading:10198190-Animals, pubmed-meshheading:10198190-Antihypertensive Agents, pubmed-meshheading:10198190-Blood Pressure, pubmed-meshheading:10198190-Body Weight, pubmed-meshheading:10198190-Calcium, pubmed-meshheading:10198190-Captopril, pubmed-meshheading:10198190-Dose-Response Relationship, Drug, pubmed-meshheading:10198190-Fluorescent Antibody Technique, pubmed-meshheading:10198190-Forskolin, pubmed-meshheading:10198190-Hypertension, pubmed-meshheading:10198190-Male, pubmed-meshheading:10198190-Myocardium, pubmed-meshheading:10198190-Norepinephrine, pubmed-meshheading:10198190-Rats, pubmed-meshheading:10198190-Rats, Inbred SHR, pubmed-meshheading:10198190-Rats, Wistar, pubmed-meshheading:10198190-Receptors, Adrenergic, beta, pubmed-meshheading:10198190-Receptors, Opioid, kappa, pubmed-meshheading:10198190-Systole
pubmed:year
1999
pubmed:articleTitle
Cross-talk between cardiac kappa-opioid and beta-adrenergic receptors in developing hypertensive rats.
pubmed:affiliation
Department of Physiology, Faculty of Medicine, University of Hong Kong, Hong Kong.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't