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Blood vessel adaptation to gravity in a semi-arboreal snakeThe effects of vasoactive agonists on systemic blood vessels were examined with respect to anatomical location and gravity acclimation in the semi-arboreal snake, Elaphe Obsoleta. Major blood vessels were reactive to putative neurotransmitters, hormones or local factors in vessel specific patterns. Catecholamines, adenosine triphosphate, histamine and high potassium (80 mM) stimulated significantly greater tension per unit vessel mass in posterior than anterior arteries. Anterior vessels were significantly more sensitive to catecholamines than midbody and posterior vessels. Angiotensin II stimulated significantly greater tension in carotid artery than in midbody and posterior dorsal aorta. Arginine vasotocin strongly contracted the left and right aortic arches and anterior dorsal aorta. Veins were strongly contracted by catecholamines, high potassium and angiotensin II, but less so by adenosine triphosphate, arginine vasotocin and histamine. Precontracted vessel were relaxed by acetylcholine and sodium nitroprusside, but not by atrial natriuretic peptide or bradykinin. Chronic exposure of snakes to intermittent hypergravity stress ( + 1.5 Gz at tail) did not affect the majority of vessel responses. These data demonstrate that in vitro tension correlates with that catecholamines, as well as other agonists, are important in mediating vascular responses to gravitational stresses in snakes.
Document ID
20040173318
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Conklin, D. J.
(NASA Ames Research Center Moffett Field, CA United States)
Lillywhite, H. B.
Olson, K. R.
Ballard, R. E.
Hargens, A. R.
Date Acquired
August 22, 2013
Publication Date
January 1, 1996
Publication Information
Publication: Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology
Volume: 165
Issue: 7
ISSN: 0174-1578
Subject Category
Life Sciences (General)
Distribution Limits
Public
Copyright
Other
Keywords
NASA Discipline Number 14-10
NASA Program Space Physiology and Countermeasures
NASA Discipline Cardiopulmonary
NASA Center ARC

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