The effect of variations in heart rate and regional distribution of blood flow on the normal pressor response to diving in ducks

The Journal of Physiology
P J Butler, D R Jones

Abstract

1. During a 2 min period of submersion of normal ducks, sciatic artery blood flow fell to 10 +/- 1.5% control and carotid artery blood flow was reduced to 71 +/- 7% control. Mean arterial blood pressure (M.A.P.), however, was maintained at 83 +/- 3.5% of control. The whole animal showed a constrictor response during submersion, with the sciatic vascular bed showing average constriction. Both resistance to flow and yield pressure increased in the sciatic bed but changed little in the carotid bed. After 1 min submersion P(a,O2) was 52 +/- 1 mm Hg.2. Upon emersion, as soon as ventilation commenced, the whole animal showed a dilator response. The carotid bed exhibited marked vasodilatation whereas the sciatic bed returned to its control level.3. After alpha-receptor blockade, ducks were submerged for 1 min. During this time M.A.P. fell to 64 +/- 5.6% of control and heart rate was reduced to 49 +/- 8.3% of control. Blood flow through the sciatic and carotid arteries also fell to values of 41 +/- 6.9% of control and 91 +/- 13% of control respectively. There was little change in either resistance to flow or yield pressure in the sciatic bed compared to normal ducks, and the carotid bed showed reductions in resistance to flow and yield...Continue Reading

Citations

Jan 1, 1980·Comparative Biochemistry and Physiology. C: Comparative Pharmacology·B A Gooden
Nov 1, 1974·Electroencephalography and Clinical Neurophysiology·J M Verlander, S E Huggins
Feb 1, 1974·Acta Physiologica Scandinavica·H T Andersen, A S Blix
Oct 1, 1974·Respiration Physiology·O S Bamford, D R Jones
Oct 1, 1990·General and Comparative Endocrinology·A M Lacombe, D R Jones
Dec 1, 1980·Acta Physiologica Scandinavica·C Bech, K Johansen
Jan 1, 1988·Annals of the New York Academy of Sciences·P Johnson
Jul 9, 2002·Journal of Basic and Clinical Physiology and Pharmacology·E OphirJ Marder
Nov 1, 1974·Zentralblatt für Veterinärmedizin. Reihe A·M Szabuniewicz, J D McCrady
Mar 20, 2001·Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology·G P OllenbergerN H West
Mar 1, 1972·Comparative Biochemistry and Physiology. A, Comparative Physiology·D R Jones, G F Holeton
Oct 1, 1973·Comparative Biochemistry and Physiology. A, Comparative Physiology·R W MillardW K Milsom

❮ Previous
Next ❯

Related Concepts

Related Feeds

Adrenergic Receptors: Trafficking

Adrenergic receptor trafficking is an active physiological process where adrenergic receptors are relocated from one region of the cell to another or from one type of cell to another. Discover the latest research on adrenergic receptor trafficking here.

Bradyarrhythmias

Bradyarrhythmias are slow heart rates. Symptoms may include syncope, dizziness, fatigure, shortness of breath, and chest pains. Find the latest research on bradyarrhythmias here.