Effect of pre- and postnatal propylthiouracil administration on the propagation of cortical spreading depression of adult rats

RESUMO

The effect of treatment with propylthiouracil early in life (PTU; 8 mg k-1 day-1, ip, from day 17 of gestation to postnatal day 42) on the susceptibility of the cerebral cortex to spreading depression (SD) was studied in 13 adult Wistar rats (90-100 days of age). Ten animals injected with Ringer solution served as control. Adult PTU-treated rats displayed a significant (P < 0.05) reduction in body weight (mean +/- SD 139.9 +/- 28.9 g vs 304.9 +/- 42.8 g) as well as wet brain weight (1.39 +/- 0.12 g vs 1.86 +/- 0.13 g) and dry brain weight (247.3 +/- 24.2 mg vs 359.4 +/- 30.1 mg). Their thyroid glands presented histological changes indicative of hypofunction and SD velocity of propagation was significantly reduced all along the 6 h of the recording session (mean +/- SD ranges 1.90 +/- 0.46 to 2.52 +/- 0.68 mm/min vs 3.49 +/- 0.57 to 3.71 +/- 0.55 mm/min). The results indicate that PTU early in life was effective in producing hypothyroidism and that in this situation cortical susceptibility to SD is impaired