For a quantitative appreciation of the role of the arterial baroreceptor reflex in circulatory regulations in man, studies in chronic, conscious animals are indispensable. Even in animals, however, identifying the arterial baroreceptor reflex performance with accuracy is difficult for various reasons. We propose to attack, first, two technical problems which have seriously hampered our chronic dog studies; (1) Electromagentic flow signal via a perivascular probe is dependent on arterial pressure. We propose to identify the magnitude of the pressure-dependent change in aortic wall resstance and find ways to correct this error in flow signal. (2) The Edis-Shepherd method for cervical aortic nerve transection is difficult and , even if performed successfully, the denervation is incomplete. We propose to train ourselves in the and alternative techniques. We will be better prepared then to return to the following on-going researches. (3) Analysis, in aortic nerve denervated dogs, of the carotid sinus reflex performance during change in the head level which causes a very natural forcing of the reflex and (4) a mild, reflex in conscious and anesthetized states. We continue these experiments, with better techniques for flow measurement and aortic nerve elimination.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL014529-15
Application #
3334798
Study Section
Cardiovascular and Pulmonary Research B Study Section (CVB)
Project Start
1978-12-01
Project End
1988-11-30
Budget Start
1985-12-01
Budget End
1986-11-30
Support Year
15
Fiscal Year
1986
Total Cost
Indirect Cost
Name
Johns Hopkins University
Department
Type
Schools of Medicine
DUNS #
045911138
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Shigemi, K; Brunner, M J; Shoukas, A A (1994) Alpha- and beta-adrenergic mechanisms in the control of vascular capacitance by the carotid sinus baroreflex system. Am J Physiol 267:H201-10
Shoukas, A A (1993) Overall systems analysis of the carotid sinus baroreceptor reflex control of the circulation. Anesthesiology 79:1402-12
Haase, E B; Shoukas, A A (1992) Blood volume changes in microcirculation of rat intestine caused by carotid sinus baroreceptor reflex. Am J Physiol 263:H1939-45
Lash, J M; Haase, E; Shoukas, A A (1992) Systemic responses to carotid occlusion in the anesthetized rat. J Appl Physiol 72:1247-54
Shoukas, A A; Callahan, C A; Lash, J M et al. (1991) New technique to completely isolate carotid sinus baroreceptor regions in rats. Am J Physiol 260:H300-3
Haase, E B; Shoukas, A A (1991) Carotid sinus baroreceptor reflex control of venular pressure-diameter relations in rat intestine. Am J Physiol 260:H752-8
Lash, J M; Shoukas, A A (1991) Pressure dependence of baroreceptor-mediated vasoconstriction in rat skeletal muscle. J Appl Physiol 70:2551-8
Shoukas, A A; Bohlen, H G (1990) Rat venular pressure-diameter relationships are regulated by sympathetic activity. Am J Physiol 259:H674-80
Yamazaki, T; Sagawa, K (1989) Summation of sinoaortic baroreflexes depends on size of input signals. Am J Physiol 257:H465-72
Katoh, N; Sheriff, D D; Siu, C O et al. (1989) Relative importance of four pressoregulatory mechanisms after 10% bleeding in rabbits. Am J Physiol 256:H291-6

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