| Mechanism of intracardiac shunting in the turtle Pseudemys scripta. | |
| | |
MedLine Citation:
|
PMID: 1621878 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Two principal hypotheses account for right-left (R-L) intracardiac shunting in reptiles. The "pressure shunting" hypothesis proposes no functional separation between the ventricular cava during systole. The "washout shunting" hypothesis suggests that during systole, the cavum pulmonale (CP) is functionally separate from the rest of the ventricle. The purpose of this study was to test these hypotheses during control, after acetylcholine (ACh) administration, after epinephrine (Epi) administration, and during apnea. Anesthetized (pentobarbital) turtles (Pseudemys scripta) were mechanically ventilated and three nonocclusive catheters were implanted into the right atrium (RAt), left atrium (LAt), and CP. In addition, three blood gas catheters connected to a mass spectrometer were implanted into the RAt, LAt, and right or left aortic arch for measurement of PO2. A tracer gas, He dissolved in saline, was sequentially injected into the three cardiac chambers and was detected by the mass spectrometer. The presence of R-L shunting was assessed with the blood PO2 and PHe measurements. ACh produced R-L shunting in all animals. No R-L shunting occurred after Epi administration and 20 min of apnea. In all animals after ACh administration, He was detected in an aorta after He infusion in the RAt and LAt, but never after infusion of He into the CP. These results from this preparation are inconsistent with the pressure hypothesis and support the washout hypothesis of intracardiac shunting. |
| | |
Authors:
|
J W Hicks; G M Malvin |
Related Documents
:
|
7381538 - Experimental syringomyelia: the relationship between intraventricular and intrasyrinx p... 9009938 - Changes in cerebrospinal fluid pressure and lactate concentrations during thoracoabdomi... 9402598 - Telemetric intraventricular pressure measurements after third ventriculocisternostomy i... 16121978 - Novel laser tissue-soldering technique for dural reconstruction. 3306698 - Diagnostic information provided by ambulatory blood pressure monitoring. 7966668 - Cardiovascular performance and core temperature during transurethral prostatectomy. |
Publication Detail:
|
Type: Journal Article; Research Support, U.S. Gov't, Non-P.H.S.; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
|
Title: The American journal of physiology Volume: 262 ISSN: 0002-9513 ISO Abbreviation: Am. J. Physiol. Publication Date: 1992 Jun |
Date Detail:
|
Created Date: 1992-08-04 Completed Date: 1992-08-04 Revised Date: 2007-11-14 |
Medline Journal Info:
|
Nlm Unique ID: 0370511 Medline TA: Am J Physiol Country: UNITED STATES |
Other Details:
|
Languages: eng Pagination: R986-92 Citation Subset: IM |
Affiliation:
|
Oxygen Transport Program, Lovelace Medical Foundation, Albuquerque, New Mexico 87108. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Acetylcholine
/
pharmacology Animals Apnea / physiopathology Coronary Circulation / drug effects, physiology* Epinephrine / pharmacology Heart Injections Reference Values Turtles / physiology* |
| Grant Support | |
ID/Acronym/Agency:
|
HL-38942/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
|
51-43-4/Epinephrine; 51-84-3/Acetylcholine |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Exercise-induced sympathetic FFA mobilization in VMH-lesioned rats is normalized by fasting.
Next Document: Automaticity and the ACT* theory.