To observe the effects of dexmedetomidine (DEX) and chloral hydrate (CHL) on apoptosis of hippocampal neurons in neonatal rats in vitro.

Normal saline (NS) was used as negative control, and the drug solution was added to the nerve cell culture medium at a ratio of 1∶6 volume. The CHL group was added with the final concentration of chloral hydrate (3.5 mmol/L), the DEX group was added with the final concentration of dexmedetomidine (0.7 μmol/L). Group C+ D was mixed with dexmedetomidine and chloral hydrate. The final concentration of the two drugs was the same as that of CHL group and DEX group. Newborn SD rats were killed and brain was taken. Hippocampal tissue was dissected under microscope, then were digested and washed to make cell suspension. After 7 days of primary culture, the drug containing medium was added and incubated at constant temperature for 24 hours. The active cysteine aspartate protease 3 (cleaved caspase-3) was detected using Western blot method . The experiment was repeated three times.

The results showed that cleaved caspase-3 bands in CHL group were enhanced by Western blot method, while in group C+ D they were reduced, and those in DEX group and NS group were not significant. Compared with NS group, cleaved caspase-3 expression in DEX group was no difference (0.15±0.12) vs. (0.09±0.05), but significantly increased in CHL group (1.20±0.00), (P<0.01). Compared with the group of CHL, the expression of cleaved caspase-3 in group C+ D decreased significantly (P<0.01).

Chloral hydrate can induce apoptosis of hippocampal neurons in neonatal rats in vitro. Dexmetomidine not only induce apoptosis, but also alleviate the apoptosis induced by chloral hydrate.