Insulin increases blood volume in human skeletal muscle studies
using [15o]-labeled carbon monoxide and positron emission
tomography.
Raitakari, Maria, M. Juhani Knuuti, Ulla Ruotsalainen, Hanna Laine,
Pekka M[umlaut]akel[umlaut]a, Mika Ter[umlaut]as, Hannu
Sipil[umlaut]a, Tuula Niskanen, Olli T. Raitakari, Hidehiro Iida,
Risto H[umlaut]ark[diaeresis]onen, Uno Wegelius, Hannele Yki
-J[umlaut]arvinen, and Pirjo Nuutila.
Turku Medical Cyclotron/PET Center, Departments of Nuclear Medicine
and Medicine, Department of Clinical Physiology, University of Turku,
FIN-20520 Turku, Finland; Research Center for Brain and Blood
vessels, Akita, Japan; The University of Texas, Health Science Center
at San Antonio, San Antonio, Texas 78284 - 7886; and the Department
of Medicine, University of Helsinki, FIN-00290 Helsinki, Finland;
APStracts 2:0157E, 1995.
High insulin concentrations increase blood flow in the leg, but it is
unknown, whether this effect is associated with a change in muscle
blood volume. In the present study we used positron emission
tomography combined with inhalation of [15O]-labeled carbon monoxide
to quantitate the effect of insulin on skeletal muscle blood volume
in humans. The reproducibility of the method was determined from two
consecutive measurements performed in the basal state in 5 normal
subjects. The coefficient of variation of the repeated measurements
was 3.0+/-1.8%. In 14 normal subjects (age 35+/-3 years, body mass
index 24.9+/-1.3 kg/m2, mean+/-SE) skeletal muscle blood volume was
determined in the femoral region in the basal state and during
euglycemic hyperinsulinemia (serum insulin 3200+/-190 pmol/L). The
mean muscle blood volume was 3.3+/-0.1 mL/0.1 kg muscle in the basal
state. Insulin increased muscle blood volume by 9+/-2% to 3.6+/-0.2
mL/0.1 kg muscle, p<0.01). The rate of whole body glucose uptake
was 53+/-6 [mu]mol/kg/min and correlated with muscle blood volume
during insulin stimulation (r=0.65, p<0.02). We conclude that
high insulin concentrations exert a true vasodilatory effect in human
skeletal muscle.
Received 30 March 1995; accepted in final form 19 April 1995.
APS Manuscript Number E150-5.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 30 July 1995.