In a study of muscle metabolism (4), lactate dehydrogenase activity in skeletal and cardiac
muscle of rats was measured by disk electrophoresis. There was an increase in the enzyme's activity in
both kinds of muscle 1-2 days after exposure to 200 gauss, 50 Hz, for 24 hours; histological changes
indicative of glycolytic processes were also found. These observations were consistent with an earlier
report of impaired functional activity of muscle following EMF exposure (5). After 1 month, rabbits
exposed to 30-40 kv/m, 05 Hz, were unable to lift a weight as large as that lifted by the nonexposed
rabbits.
The sensitivity of metabolic parameters to EMFs is underscored by studies that involve EMFs
which have intensities comparable to typical environmental fields; the Mathewson et al. study (6) is a
blood example. Rats were exposed for 28 days to 2, 10, 20, 50 and 100 v/m in three replicate
experiments, following which complete blood chemistries were performed; the serum glucose levels
are listed in table 8.2A. Although some differences between the control and exposed groups were seen,
no trend or dose-effect relationship was manifested and consequently, the authors regarded the data as
having failed to show a biological effect of the EMF (6). But the 60-Hz electric field in the test cages
was 0.18-9.15 v/m, depending on the particular test cage location (8). As a consequence, the 4 5 -Hz,
2v/m group is more properly viewed as a control group in relation to the 50-100 v/m exposed groups.
When we did this, the Mathewson data revealed significant increases in serum glucose in each replicate
(Table 8.2B). (This approach to the Mathewson data also suggests the existence of effects on other
parameters, including globulins, protolipids, and triglycerides.)
Table 8.2. AVERAGE GLUCOSE LEVELS IN THREE REPLICATE EXPERIMENTS
Cellular bioenergetics can be altered by EMFs (10-14): the changes seem to be adaptive in
ELECTROMAGNETISM & LIFE - 103