Abstract |
Cardiovascular regulatory systems were examined in the dogfish shark after hemorrhage of 1% of body weight. An immediate 45% decrease in mean dorsal aortic pressure and delayed increases in plasma epinephrine concentration and plasma norepinephrine concentration were noted. During the recovery period following hemorrhage, the catecholamine levels peaked ( epinephrine 203% of control, norepinephrine 148% of control) and then returned toward control values. Hematocrit, however, continued to decline as blood pressure recovered. Phentolamine pretreatment, which in itself caused a 55% decrease in dorsal aortic pressure, did not prevent the recovery of blood pressure after hemorrhage. This study indicates that 1) hemorrhage causes an increase in circulatory catecholamine concentration, possibly by a baroreceptor reflex; 2) volume recruitment, as indicated by the drop in hematocrit, is a major mechanism contributing to the recovery of dorsal aortic pressure after hypotension; and 3) alpha-adrenergic receptors are not necessary for the recovery of dorsal aortic pressure after hemorrhage.
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Authors | R G Carroll, D F Opdyke, N E Keller |
Journal | The American journal of physiology
(Am J Physiol)
Vol. 246
Issue 5 Pt 2
Pg. R825-8
(May 1984)
ISSN: 0002-9513 [Print] United States |
PMID | 6721002
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)
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Chemical References |
- Norepinephrine
- Epinephrine
- Phentolamine
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Topics |
- Animals
- Aorta
- Blood Pressure
(drug effects)
- Blood Vessels
(physiopathology)
- Dogfish
(physiology)
- Epinephrine
(blood)
- Hematocrit
- Hemorrhage
(blood, physiopathology)
- Norepinephrine
(blood)
- Phentolamine
(pharmacology)
- Sharks
(physiology)
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