the effects of extremely low frequency pulsed electromagnetic field on collagen synthesis of rat skin: a biochemical and histoligical approach

the efficacious effects of pulsed electromagnetic field (pemf) under the certain field parameters like frequency and the field intensity have been reported for various tissue and molecules. since collagen is found abundantly in most tissue structures, this research was designed to further investigate the effects of extremely low frequency (elf) pemf on the synthesis of the epidermal collagen. to do the task, six groups of animals each consisting of eight mature male rats were selected randomly as one group for the control and five for the test. the field was generated by using a parallel set of helmholtz coil. the first set of experiments was carried out at the peak intensity of 2 mt (milli tesla) for different frequencies of 25, 50 and 100 hz. since the most effective frequency turned out to be 25 hz, another set of experiment was conducted using this frequency and two different field intensities of 1 and 4 mt. the field was applied for 2.5 h/day lasting for 8 days, keeping the same procedure for the control group except for the field turned off. on the ninth day, the rats were sacrificed and the skin samples from the dorsal region were taken for biochemical assessment of collagen by measuring hydroxyproline content using stegeman-stalder method and histological assessment. the data indicated that pulsed electromagnetic field of 2 mt at 25 hz increased the collagen synthesis (p<0.05). the other intensities and frequency setting did not have much distinguishable effect, however, at the frequency of 25 hz and 4 mt, the field effect on the collagen increase was also noticeable. it was concluded that applying the field parameters of 25 hz and 2 mt peak intensity for 2.5 h/day during eight days rendered a significant increase in collagen synthesis in rat skin. histological observations were consistent with the biochemical findings.