Effects of electrical stimulation on lymphatic flow and limb volume in the rat.
OBJECTIVE
The mechanism by which electrical stimulation affects edema has not been elucidated. The purpose of this study was to determine whether subcontraction high-voltage stimulation (SC-HVS) (ie, electrical stimulation that did not elicit a visible contraction) applied to the right hind limbs of rats would (1) alter the rate of lymphatic uptake of injected albumin labeled with Evans blue dye (AL-EBD) and (2) affect experimentally induced edema.


METHODS
The paws of 28 anesthetized Sprague-Dawley rats (mean weight = 263 g, SD = 48 g) were injected with AL-EBD. The experimental group (n = 13) received 1 hour of SC-HVS, and the control group (n = 15) received sham treatment consisting of the same treatment administered to the experimental group but without the SC-HVS. Blood samples and volume measurements were obtained at intervals over a 7-hour period.


RESULTS
Analysis of variance and post hoc testing indicated that higher amounts of AL-EBD were taken up by the lymph of the experimental group animals as compared with the control group animals at each time period following the treatment. The experimental group's AL-EBD reached significance immediately after treatment, whereas the control group required an additional 4 hours. There was no significant reduction in limb volume in either group.


CONCLUSIONS
The SC-HVS significantly increased the uptake of AL-EBD by lymphatic vessels, but it did not cause a significant decrease in the induced edema. The results of this study indicate that SC-HVS has the potential to reduce edema by increasing lymphatic uptake of proteins.
University of Maryland at Baltimore.
H A
HA
Cook
M
M
Morales
E M
EM
La Rosa
J
J
Dean
M K
MK
Donnelly
P
P
McHugh
A
A
Otradovec
K S
KS
Wright
T
T
Kula
S H
SH
Tepper
D000418:Albumins / Q000493:pharmacokinetics; D000704:Analysis of Variance; D000818:Animals; D004195:Disease Models, Animal; D004599:Electric Stimulation Therapy / Q000379:methods*; D005069:Evaluation Studies as Topic; D005070:Evans Blue / Q000493:pharmacokinetics; D006614:Hindlimb / Q000473:pathology / Q000503:physiopathology; D008196:Lymph / Q000502:physiology*; D008209:Lymphedema / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D009929:Organ Size; D051381:Rats; D017207:Rats, Sprague-Dawley; D012212:Rheology; D013997:Time Factors
D000418:Albumins; D005070:Evans Blue