Effects of static electromagnetic fields on chick embryo pineal gland development

The effects of static electromagnetic fields on the development of the chick embryo pineal gland were studied. A total of 144 fertilized White Leghorn eggs were sacrificed after 5, 10 and 15 days of incubation. The stage of development was determined in all embryos using the Hamburger and Hamilton method [J Morphol 49: 88-92, 1951]. The various morphometric parameters (diameter and distance of the pineal gland and its lumen) were measured on serial 7-mu m-thick sections. The data were obtained in a morphometer and processed statistically. The intensities of the static electromagnetic fields were 18 and 36 mT. Control and exposed embryos were equally distributed and randomly assigned. After 5 days of incubation, 25% of embryos exposed to a static electromagnetic field of 18 mT had a more advanced stage of development than controls and embryos exposed to 36 mT. On the 10th and 15th day, embryos exposed to either 18 or 36 mT tended to be more developed than controls. In the morphometric study, results were similar for the controls and exposed embryos after 5 and 10 days of incubation. However, the values of the 15-day-old embryos exposed to static magnetic fields were lower than the values of the controls (p > 0.01). These differences were more pronounced in the embryos exposed to 36 mT. These results seem to indicate that static electromagnetic fields affect the development and growth of embryos unequally, and that their action can depend not only on the intensity of the static electromagnetic field, but also on the length of exposure and the organ which is developing. It may be interesting to use these data in ultrastructural and physiological studies.