[Effect of infrasound on ultrastructure and permeability of rat's blood-retinal barrier].
OBJECTIVE
To investigate the possible effect of infrasound on the ultra-structure and permeability of rat's blood-retinal barrier (BRB).


METHODS
Ultra-structural changes of BRB were observed through the injection of lanthanum nitrate (La), which was used as a tracer to demonstrate the breakdown of the BRB, into blood vessels. Fifteen mature male rats divided into 5 groups were exposed to infrasound at a 8 Hz frequency, 130 dB sound pressure level in a pressure chamber especially designed for the experiment for 0, 1, 7, 14, 21 days, respectively.


RESULTS
Under the action of infrasound, along with the prolongation of exposure, the damage of BRB was severer and severer. On the 1st day, there was no significant change in La leakage. On the 7th day, La diffused in the interphotoreceptor space at nuclear level. On the 14th day, La granules could be seen in the space of nervous cells. Finally, on the 21st day, La was found between synapses, synapses and nerve cells, as well as between the nerve cells and supporting cells, then sometimes reached vitreous body. Under the electron microscope, there were no significant morphological changes, but changes related to metabolism, such as edematous mitochondria, dilated rough endoplasmic reticula, precipitation of glycogen grandules, widening of perinuclear space, etc.


CONCLUSIONS
The results thus suggest that the exposure to infrasound cause the breakdown of rat's blood-retinal barrier and visual impairment.
Qiu
Ping
P
Department of Clinical Aerospace Medicine, Faculty of Aviation Medicine, Guangzhou 510515, China. pingqiu817@263.net
Zhang
Zuoming
Z
Jiang
Yong
Y
Gou
Qun
Q
Wang
Bing
B
Gou
Lin
L
Chen
Jingzao
J
D000818:Animals; D001813:Blood-Retinal Barrier / Q000502:physiology*; D002199:Capillary Permeability / Q000502:physiology*; D008297:Male; D008854:Microscopy, Electron; D009474:Neurons / Q000473:pathology / Q000648:ultrastructure; D009622:Noise / Q000009:adverse effects*; D010786:Photoreceptor Cells / Q000098:blood supply / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012164:Retinal Diseases / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D012171:Retinal Vessels / Q000294:innervation / Q000503:physiopathology / Q000648:ultrastructure; D013997:Time Factors