Pineal ‘Synaptic Ribbons’ and Serum Melatonin Levels in the Rat following the Pulse Action of 52-Gs (50-Hz) Magnetic Fields: An Evolutive Analysis over 21 Days

Abstract

In continuation of earlier studies, we have investigated the influence of 52-Gs (50-Hz) magnetic fields on the evolution of pinealocyte ‘synaptic ribbons’ and serum melatonin levels in rats, following 30 min daily exposure. The animals were sacrificed after 1, 3, 7, 15 and 21 days. A significant decrease in the number of synaptic ribbons was observed after 15 and 21 days, together with a significant drop in serum melatonin concentrations after 15 days. The mediating role of the retina in these modifications and magnetic field effects is discussed.

Nocturnal excretion of a urinary melatonin metabolite among electric utility workers

“…Animal experiments indicate that several weeks of exposure to 50-to 60-Hz electric or magnetic fields over a large portion of the day appear to be the most effective means of suppressing melatonin (47-52) although there are some inconsistencies (53-56). Short-term exposures have been ineffective (57, 58) unless repeated daily for several weeks (59).…”

60 Hz magnetic field exposure and urinary 6-sulphatoxymelatonin levels in the rat

“…An inhibition of nocturnal serum melatonin and NAT was also observed in rats exposed The rats were given water and commercial rat feed ad libitum and were maintained on a 12 h daily photope-to 100 mT, 50 Hz [Selmaoui and Touitou, 1995]. Martinez Soriano et al [1992] observed a decrease in the riod (white fluorescent lights providing an illuminance of approximately 350 lux at the cage; on at 07:00 h number of daytime pineal synaptic ribbons and serum melatonin levels in rats, following 15 days of 30 min and off at 19:00 h) and an ambient temperature of 22 { 0.5 ЊC during a 2 week acclimation period prior daily exposure to the pulse action of 5.2 mT (50 Hz) magnetic field. Kato et al [1993Kato et al [ , 1994a reported that to the commencement of the experiment and throughout the experimental period.…”

“…It is proposed influence on the above-mentioned conditions. For exthat MF may also be detected by the retina and the ample, melatonin has an inhibitory effect on cancer [Tamarkin et al, 1982;Blask, 1993] and plays a role in reproductive function [Reiter, 1983;Pevet, 1988]. In addition, disturbances in endogenous melatonin levels Contract grant sponsor: Ontario Hydro, Canada.…”