Increased vascular permeability in the circumventricular organs of adult rat brain due to stimulation by extremely low frequency magnetic fields.
It has been demonstrated that the exposure of biological systems to magnetic fields (MFs) can produce several beneficial effects: tissue recovery in chronic wounds, re-establishment of blood circulation after tissue ischemia or in necrotic tissues, improvement after epileptic episodes, angiogenesis, etc. In the current study, the effects of extremely low frequency (ELF) MF on the capillaries of some circumventricular organs (CVOs) are demonstrated; a vasodilator effect is reported as well as an increase in their permeability to non-liposoluble substances. For this study, 96 Wistar male rats (250 g body mass) were used and divided into three groups of 32 rats each: a control group (no treatment); a sham ELF-MF group; and an experimental group subjected to ELF-MF (120 Hz harmonic waves and 0.66 mT, root mean square) by the use of Helmholtz coils. All animals were administered colloidal carbon (CC) intravenously to study, through optical and transmission electron microscopy, the capillary permeability in CVOs and the blood-brain barrier (BBB) in brain areas. An increase in capillary permeability to CC was detected in the ELF-MF-exposed group as well as a significant increase in vascular area (capillary vasodilation); none of these effects were observed in individuals of the control and sham ELF-MF groups. It is important to investigate the mechanisms involved in the phenomena reported here in order to explain the effects of ELF-MF on brain vasculature.
Laboratory of Cellular Neurobiology, Biological and Agricultural Sciences University Center (CUCBA), University of Guadalajara, Guadalajara, Mexico.
Yanet K
YK
Gutiérrez-Mercado
Luis
L
Cañedo-Dorantes
Ulises
U
Gómez-Pinedo
Gregorio
G
Serrano-Luna
Jacinto
J
Bañuelos-Pineda
Alfredo
A
Feria-Velasco
D000818:Animals; D001812:Blood-Brain Barrier / Q000502:physiology* / Q000528:radiation effects; D002196:Capillaries / Q000528:radiation effects*; D002199:Capillary Permeability / Q000528:radiation effects*; D002244:Carbon; D002552:Cerebral Ventricles / Q000098:blood supply / Q000528:radiation effects; D060526:Magnetic Fields; D008297:Male; D051381:Rats; D017208:Rats, Wistar
C028433:chinese ink; D002244:Carbon