Journal article
Stimulation of parabrachial neurons elicits a sympathetically mediated pressor response in cats
American journal of physiology. Heart and circulatory physiology, Vol.255(6), pp.H1349-H1358
12/01/1988
DOI: 10.1152/ajpheart.1988.255.6.H1349
PMID: 3202199
Abstract
We examined the role of the parabrachial neuronal mass in mediating the pressor response to electrical stimulation of parabrachial nucleus (PBN). In anesthetized cats, 100 mM L-glutamate (L-glu) was microinjected into PBN at sites from which low-intensity (25 microA) electrical stimulation evoked a pressor response. Arterial pressure, heart rate, and, in some animals, renal or phrenic nerve activity were monitored. Microinjection of L-glu caused an increase in arterial pressure that was comparable with that elicited by low-intensity electrical stimulation. Electrical stimulation, and to a lesser extent L-glu microinjection, caused an increase in renal sympathetic nerve activity but no significant change in heart rate. No consistent change in central respiratory drive accompanied the pressor response. These responses were preserved after baroreceptor denervation but were blocked by intravenous administration of the alpha-adrenergic receptor antagonist phentolamine. Microinjection into PBN of 2 mM kainic acid, which selectively depolarizes neurons but spares axons, reversibly blocked the arterial pressure and renal nerve responses to the 25-microA electrical stimulus. We conclude that the pressor response elicited by electrical stimulation of PBN in the anesthetized cat is mediated by cellular elements in PBN, not by fibers of passage. Because phentolamine completely blocked the pressor response, we suggest that it is subserved peripherally by sympathetic alpha-adrenergic rather than humoral (e.g., angiotensin, vasopressin) vasoconstrictor mechanisms. Finally, our data indirectly suggest that PBN stimulation may differentially engage efferent components of the sympathetic nervous system to elicit the pressor response.
Details
- Title: Subtitle
- Stimulation of parabrachial neurons elicits a sympathetically mediated pressor response in cats
- Creators
- Jon S Hade - Department of Internal Medicine, University of Iowa College of Medicine, Iowa City 52242Steven W Mifflin - Department of Internal Medicine, University of Iowa College of Medicine, Iowa City 52242Theodore S Donta - Department of Internal Medicine, University of Iowa College of Medicine, Iowa City 52242Robert B Felder - Department of Internal Medicine, University of Iowa College of Medicine, Iowa City 52242
- Resource Type
- Journal article
- Publication Details
- American journal of physiology. Heart and circulatory physiology, Vol.255(6), pp.H1349-H1358
- DOI
- 10.1152/ajpheart.1988.255.6.H1349
- PMID
- 3202199
- ISSN
- 0363-6135
- eISSN
- 1522-1539
- Language
- English
- Date published
- 12/01/1988
- Academic Unit
- Radiology; Iowa Neuroscience Institute; Cardiovascular Medicine; Internal Medicine
- Record Identifier
- 9984065394802771
Metrics
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