Alignment of microvascular units along muscle fibers of hamster
retractor.
Emerson, Geoffrey G., and Steven S. Segal.
The John B. Pierce Laboratory and Department of Chemical
Engineering, Yale University, New Haven, Connecticut 06519
APStracts 3:0395A, 1996.
When muscle fibers contract, blood flow requirements increase along
their entire length. However, the organization of capillary perfusion
along muscle fibers is unclear. The microvascular unit (MVU) is
defined as a terminal arteriole and the group of capillaries it
supplies. Using the parallel-fibered retractor muscle (length, 31 ( 1
mm), we investigated whether neighboring MVUs along the muscle
(fiber) axis perfused the same group of muscle fibers. Male golden
hamsters (n=8; 106 ( 5 g) were anesthetized and Microfil was perfused
into the retractor via the abdominal aorta. Muscles were excised and
cleared in 50% glycerin to visualize MVUs relative to muscle fibers.
Fields of study (1 X 5 mm), which encompassed a row of 5-7
neighboring MVUs along a muscle fiber, were chosen from the interior
of muscles and along muscle edges. In half of the study fields, the
terminal arterioles supplying respective, MVUs originated arose from
more than one parent arteriole. On average, MVUs were 1 mm in length,
0.50 mm in width, and 0.1 mm deep; segments of 30 fibers were
contained in this tissue volume of 0.05 mm3 (= 20 MVUs / mg muscle).
Received 8 February 1996; accepted in final form 13 August 1996.
APS Manuscript Number A141-6.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 29 August 1996