Abstracts of papers presented at the thirty-eighth annual meeting of the Japanese Teratology Society

✍ Scribed by Trembath, Dimitri; Sherbondy, Andrea L.; Vandyke, Don C.; Shaw, Gary M.; Todoroff, Karen; Lammer, Edward J.; Finnell, Richard H.; Marker, Stephen; Lerner, Gary; Murray, Jeffrey C.

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 86 KB
• Volume: 59
• Category: Article
• ISSN: 0040-3709
• DOI: 10.1002/(sici)1096-9926(199905)59:5<35a::aid-tera7>3.0.co;2-y

✦ Synopsis

Causes

Hydrocephalus Following Exposure to X-Radiation at Early Gestational Stage in Mice.

Irradiation is known to cause congenital hydrocephalus, however, the pathogenesis of this anomaly remains to be elucidated. The purpose of this experiment is to clarify the mechanism of hydrocephalus. Pregnant Slc:ICR mice were exposed to X-rays at a dose of 1.4 Gy on gestational day 7 (G7), in which the highest incidence of hydrocephalus was achieved. Histological findings of progeny were: 1) many dead cells were observed in the neuroepithelium and mesenchyme of the embryos at 4 through 12 hours after exposure to X-rays; 2) thinning of the neuroepithelium and mesenchyme of the lamina terminalis was found on G9; 3) abnormal development of the choroid plexus was detected on G13; 4) hydrocephalus manifested on G15; and 5) in hydrocephalic brain hypoplastic and shrunk choroid plexus appeared on G19. In severe hydrocephalic brain, which manifested dome shaped head in postnatal development, occlusion of the cerebral aqueduct was observed. In mild hydrocephalic cases cerebral aqueduct was open. These results suggest that cell death in the mesenchyme of the G7 embryos due to X-ray exposure causes abnormal development of the choroid plexus, and this abnormality implicates dysfunction of choroid plexus in the pathogenesis of congenital hydrocephalus. The stenosis of cerebral aqueduct would be a secondary phenomenon by compression of the mid brain with dilated ventricles.