AJP - Endocrinology and Metabolism, Vol 249, Issue 2 183-E186, Copyright © 1985 by American Physiological Society
Altered carnitine metabolism in spontaneously hypertensive rats
K. A. Foster, B. O'Rourke and D. K. Reibel
Carnitine metabolism was examined in spontaneously hypertensive rats (SHR).
Carnitine levels were elevated by 25% in hypertrophied hearts of 10- and
15-wk-old SHR when compared with Wistar-Kyoto (WKy) controls. This
elevation was associated with a greater than 25% increase in total serum
carnitine. The elevated serum carnitine does not appear to be due to
increased mobilization from skeletal muscle because carnitine levels were
elevated by 25% in gastrocnemius and diaphragm of SHR. Elevated serum
carnitine is also not a result of reduced urinary excretion because daily
urinary carnitine output was increased by 150% in SHR. These findings
suggest that the most likely mechanism for increased serum carnitine is
increased carnitine synthesis by the liver. The changes in carnitine
metabolism in SHR appear to occur between 5 and 10 wk of age, because the
carnitine levels in serum and organs were comparable in 5-wk-old WKy and
SHR. The observed alterations in tissue and serum carnitine levels may
result in altered fatty acid utilization in SHR.
