Effects of isradipine and other calcium antagonists on arteriovenous-shunt flow in anesthetized rabbits and cats

Journal Article · Mon Apr 17 00:00:00 EDT 1989 · Am. J. Med.; (United States)

DOI:https://doi.org/10.1016/0002-9343(89)90189-7· OSTI ID:6030924

Hof, R P

The effects of vasodilators on arteriovenous (AV)-shunt flow was investigated in anesthetized cats and rabbits, using the tracer microsphere method. In cats, the calcium antagonist isradipine reduced AV-shunt flow; verapamil showed a similar tendency and nicardipine was without effect. Dihydralazine strongly increased, but nitroglycerin and dipyridamole decreased AV-shunt flow. In rabbits, the effects of isradipine and verapamil were similar to those seen in cats. Sodium nitroprusside had no effect, whereas prazosin, minoxidil, and the potassium-channel activator cromakalim increased AV-shunt flow. The contrasting effects of drugs sharing the same mechanism of action suggest that target-tissue selectivity is more important than the mechanism of action. An increase of AV-shunt flow is unlikely to be beneficial but could be associated with a number of undesirable side effects. It might negatively affect migraine sufferers and, if AV-shunt dilatation shows no tolerance development, it represents an unnecessary hemodynamic burden for the heart.

• Research Organization: Sandoz Ltd., Basel (Switzerland)
• OSTI ID: 6030924
• Journal Information: Am. J. Med.; (United States), Vol. 86:4A
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
ANTIHYPERTENSIVE AGENTS
BIOLOGICAL EFFECTS
ARTERIES
BLOOD FLOW
VASODILATORS
VEINS
BLOOD PRESSURE
CATS
DOSE-RESPONSE RELATIONSHIPS
MICROSPHERES
PYRIDINES
RABBITS
RADIOISOTOPES
TRACER TECHNIQUES
ANIMALS
AZINES
BLOOD VESSELS
BODY
CARDIOVASCULAR AGENTS
CARDIOVASCULAR SYSTEM
DRUGS
HETEROCYCLIC COMPOUNDS
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques