Neuronal expression of inducible nitric oxide synthase in hypothyroid rat.

The expression of iNOS mRNA and protein levels was studied in hypothyroid rat cerebral cortex during early days after postnatal life. The homogenate of the cerebral cortex was examined using Real-time reverse transcription polymerase chain reaction (real-time RT PCR) and Western blot analysis. ΔCt in hypothyroid group on day 7, 14, 21 was 18.89±0.92, 18.83±0.99, 16.48±0.29, separately. While in control group, ΔCt was 20.32±0.92, 20.07±0.86, 17.96±0.50, separately. Meanwhile, the protein level was detected only in hypothyroid group of 59 ± 5% on day 14. On day 21, iNOS protein expression showed a decrease (p<0.05) in hypothyroid group (37 ± 3%), compared with control group (58 ± 4%). Our findings show the successive changes of the iNOS mRNA and protein levels in early postnatal days of hypothyroid rat brain, and confirm the cross-talk between the TH and NO signaling pathway in developing cerebral cortex of rats.