Linked Life Data

9138244

Source:http://linkedlifedata.com/resource/pubmed/id/9138244

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1997-7-18
pubmed:abstractText
In the present study we investigated the effects of microinjection into the commissural nucleus tractus solitarius (NTS) of unanesthetized rats of 2-methylserotonin (2-methyl-5-HT), a 5-HT3 receptor agonist, on the cardiac component of the baro- and chemoreflexes. The study was performed in conscious freely moving rats in order to avoid the possible effects of anesthetics on the cardiovascular responses to microinjection of neuroactive substances into the NTS. The baroreflex (phenylephrine, 0.5-2.0 micrograms/kg, i.v.) and the chemoreflex (potassium cyanide, 40 micrograms/rat, i.v) were activated in different groups of rats before and after bilateral microinjection of 2-methyl-5-HT into the NTS. Microinjections of 2-methyl-5-HT (5 nmol/50 nl) into the NTS produced a significant increase in basal mean arterial pressure (101 +/- 3 versus 125 +/- 8 mmHg), no changes in basal HR and a significant reduction in the reflex bradycardia triggered by baroreflex activation at 3 (-28 +/- 7 bpm), 10 (-35 +/- 4 bpm) and 20 min (-34 +/- 5 bpm) in comparison with the control value (-68 +/- 9 bpm). A similar reduction in the bradycardic response to chemoreflex activation was observed at 3 (-94 +/- 35 bpm), 10 (-98 +/- 38 bpm) and 20 min (-110 +/- 29 bpm) after 2-methyl-5-HT in comparison with the control value (-178 +/- 19 bpm). The effect of 2-methyl-5-HT on the basal mean arterial pressure and on the bradycardia evoked by stimulation of the baro- and chemoreflexes was blocked by pretreatment with granisetron bilaterally microinjected (500 pmol/50 nl) into the NTS. The data show that the stimulation of 5-HT3 receptors in the NTS of unanesthetized rats elicits a significant increase in basal mean arterial pressure and decreases the bradycardic response to baro- or chemoreflex activation.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0165-1838
pubmed:author
pubmed:issnType
Print
pubmed:day
14
pubmed:volume
63
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
127-36
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Microinjection of a serotonin3 receptor agonist into the NTS of unanesthetized rats inhibits the bradycardia evoked by activation of the baro- and chemoreflexes.
pubmed:affiliation
Department of Physiology, School of Medicine of Ribeirão Preto, University of São Paulo, Brazil.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't