Evidence for a local sympathetic venoarteriolar ''reflex'' in the dog hindleg

Journal Article · Sun May 01 04:00:00 EDT 1983 · Circ. Res.; (United States)

DOI:https://doi.org/10.1161/01.RES.52.5.534· OSTI ID:5296283

Henriksen, O; Amtorp, O; Faris, I; Agerskov, K

The study was performed in order to determine whether a local sympathetic venoarteriolar ''reflex'' is present in the dog hindleg. Femoral artery blood flow was measured by an electromagnetic flowmeter probe, and blood flow in the thigh muscle and subcutaneous tissue distally in the paw was measured by the local 133Xe washout technique. Twenty experiments were carried out in seven dogs unilaterally sympathectomized 2-4 weeks previously. Resting vascular tone did not differ in the sympathectomized and nonsympathectomized legs. In the control leg, venous pressure elevation caused a decrease in femoral blood flow of 49% corresponding to an increase in vascular resistance of 58%. In muscle and subcutaneous tissue vascular resistance increased by 81% and 35%, respectively. In the denervated leg, venous stasis caused no change in total vascular resistance. In muscle the vascular resistance increased by only 24%. In subcutaneous tissue, vascular resistance decreased by 12%. The effect of acute lumbar sympathectomy was studied in another group of seven dogs. Operation caused an immediate decrease in vascular resistance of 40%. The increase in vascular resistance during venous stasis in the total leg, as well as in muscle and subcutaneous tissue, was not affected. However, acute lumbar sympathectomy combined with injection of phenoxybenzamine into the femoral artery almost abolished the vasoconstriction induced by venous stasis. In muscle, the increase in vascular resistance was still present, but considerably attenuated. In subcutaneous tissue, the normal response was completely blocked. Finally, local suction induced vasoconstriction in an adjoining area not subjected to changes in vascular transmural pressure, an effect that could be blocked by local neural blockade at the site of suction. The results strongly suggest that a local sympathetic veno-arteriolar (axon) ''reflex'' is present in muscle and subcutaneous tissue in the dog hindleg.

• Research Organization: Department of Clinical Physiology, Bispebjerg Hospital, Copenhagen, Denmark
• OSTI ID: 5296283
• Journal Information: Circ. Res.; (United States), Journal Name: Circ. Res.; (United States) Vol. 52:5; ISSN CIRUA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
ARTERIES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BLOOD FLOW
BLOOD VESSELS
BODY
BODY AREAS
CARDIOVASCULAR SYSTEM
DAYS LIVING RADIOISOTOPES
DOGS
DYNAMIC FUNCTION STUDIES
EVEN-ODD NUCLEI
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LEGS
LIMBS
MAMMALS
NUCLEI
ORGANS
RADIOISOTOPES
REFLEXES
VERTEBRATES
XENON 133
XENON ISOTOPES