Mechanisms of electrical vasoconstriction.
Mark Brinton, Yossi Mandel, Ira Schachar and 1 others
PMID 29843762WHAT IT FOUND
In rats, low-voltage pulses constricted arteries through nerve pathways and recovered quickly, while high-voltage pulses constricted arteries and veins without nerve pathways and recovered slowly; the 20 V and 150 V vasoconstriction pulses did not damage vessel cells.
Key findings
01In rat saphenous vessels, 20 V, 1 ms pulses at 10 Hz constricted arteries to 41 ± 8% of initial diameter, while veins constricted to 80 ± 18%.
02Guanethidine blocked low-voltage arterial constriction, increasing stimulated diameter from 38 ± 4% to 98 ± 2%, while high-voltage arterial constriction was 30 ± 3% without blockers, 30 ± 6% with phenoxybenzamine, and 37 ± 2% with guanethidine.
03The tested 20 V and 150 V pulses showed damaged-cell counts similar to control, 1.1 ± 0.8 and 1.2 ± 0.3 a.u. versus 1.0 ± 0.6 a.u., while 300 V increased damaged cells 4.7-fold.
STILL TO COME
How it was doneWhat they found
Read the rest of this summary
You get three full summaries a month, free, and we do not ask for a card. Search, the TL;DRs and your library stay unlimited either way.
What it does not show
The study was done in rats, not people, so it does not show what would happen in a patient. The paper states that safety for clinically relevant stimulation durations greater than 30 minutes has not been shown. The solvent used for the inhibitors, DMSO, lengthened arterial recovery time after high-voltage constriction. Even without DMSO, veins did not fully dilate 15 minutes after high-voltage stimulation. Electrical stimulation also activated nearby muscles and sensory nerves, and muscle contraction decreased over time, so unwanted nerve and muscle effects were not fully controlled. Some groups had only 5 or 6 animals.
Declared interests
The supplied text names the Air Force Office of Scientific Research as funder and does not state author conflicts.
The easy way to misread this
Do not treat this as a clinical bleeding-control method for people. It tested electrical pulses in rat saphenous vessels and modeling, and the paper says safety for clinically relevant durations greater than 30 minutes has not been shown.