Laser-induced endothelial damage inhibits endothelium-dependent relaxation in the cerebral microcirculation of the mouse

Journal Article · Sun Feb 01 00:00:00 EST 1987 · Circ. Res.; (United States)

DOI:https://doi.org/10.1161/01.RES.60.2.169· OSTI ID:6469803

Rosenblum, W I; Nelson, G H; Povlishock, J T

This study demonstrates endothelium-dependent relaxation in the surface arterioles of the brain. A helium-neon laser was used to injure endothelium in situ following i.v. injection of Evans blue dye, which sensitizes the bed to the laser. Areas 18 or 36 micron in diameter were injured and no longer relaxed to either 1 ml of acetylcholine chloride or bradykinin triacetate, 80 micrograms/ml delivered for 60 seconds. Dilations to sodium nitroprusside (30 micrograms/ml) were unaffected. Normal responses to nitroprusside, plus electron microscopy, established that vascular smooth muscle was uninjured. Endothelium-dependent relaxation was impaired when only minor ultrastructural damage was present. Dilation was inhibited downstream and upstream as far as 80 micron from the center of the laser beam. This suggests a spread of endothelium injury around the site of laser impact. However, inhibition was somewhat more marked downstream than upstream, implying that a portion of the downstream response was dependent on a substance released from an upstream site. To date, very few studies have reported endothelium-dependent relaxation in vivo, especially in the microcirculation. The present study accomplishes this. Moreover, in contrast to in vitro observations of endothelium-dependent relaxation in large vessels, the in vivo elimination of endothelium-dependent relaxation in the microcirculation required neither removal of endothelium nor injury to large numbers of endothelium cells. Since endothelium-dependent relaxation in the microcirculation has now been demonstrated using three different techniques to injure endothelium, it is reasonable to conclude that the phenomenon is real.

• Research Organization: Medical College of Virginia, Richmond
• OSTI ID: 6469803
• Journal Information: Circ. Res.; (United States), Vol. 2
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BRAIN
BLOOD CIRCULATION
ENDOTHELIUM
ULTRASTRUCTURAL CHANGES
LASER RADIATION
TOXICITY
ACETYLCHOLINE
BRADYKININ
EVANS BLUE
LASERS
MICE
VASODILATION
AMINES
AMMONIUM COMPOUNDS
ANIMAL TISSUES
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
AZO COMPOUNDS
AZO DYES
BODY
CENTRAL NERVOUS SYSTEM
DRUGS
DYES
ELECTROMAGNETIC RADIATION
ESTERS
KININS
MAMMALS
MORPHOLOGICAL CHANGES
NERVOUS SYSTEM
NEUROREGULATORS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
ORGANS
PARASYMPATHOMIMETICS
PEPTIDES
POLYPEPTIDES
PROTEINS
QUATERNARY COMPOUNDS
RADIATIONS
REAGENTS
RODENTS
SULFONIC ACIDS
TISSUES
VERTEBRATES
560400* - Other Environmental Pollutant Effects