Angiotensin II binding sites in the conduction system of rat hearts

Journal Article · Tue Dec 01 04:00:00 EST 1987 · American Journal of Physiology; (USA)

OSTI ID:6945518

Saito, K; Gutkind, J S; Saavedra, J M ^[1]

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1. National Institute of Mental Health, Bethesda, MD (USA)

Angiotensin II binding sites were localized and quantified in the conduction system of the rat heart by autoradiography in combination with computerized microdensitometry. Tissue sections, containing cardiac vagus ganglia, sinus node, and atrioventricular node, were incubated with {sup 125}I-Sar{sup 1}-angiotensin II to generate autoradiograms that were compared with other autoradiograms from {sup 125}I-labeled standards. Angiotensin II binding sites were highly localized in both the sinoatrial and atrioventricular nodes and in the cardiac vagus ganglia. In contrast, binding to the angiotensin converting enzyme, determined by incubation of adjacent tissue sections with the specific enzyme inhibitor {sup 125}I-351A, was very low in these areas but high in the cardiac endothelium. The results suggest that angiotensin II may have direct chronotropic effects through stimulation of specific receptors in the conduction system of the heart and in intrinsic parasympathetic ganglia.

• OSTI ID: 6945518
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 253:6; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
ANGIOTENSIN
ANIMALS
AUTORADIOGRAPHY
BETA DECAY RADIOISOTOPES
BODY
CARDIOVASCULAR AGENTS
CARDIOVASCULAR SYSTEM
DAYS LIVING RADIOISOTOPES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
ENZYME ACTIVITY
GANGLIONS
GLOBULINS
HEART
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPES
LABELLED COMPOUNDS
MAMMALS
MEMBRANE PROTEINS
NERVOUS SYSTEM
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RADIOISOTOPES
RATS
RECEPTORS
RODENTS
VASOCONSTRICTORS
VERTEBRATES