LOW CONCENTRATIONS OF HYDROGEN-SULFIDE ALTER MONAMINE LEVELS IN THE DEVELOPING RAT CENTRAL-NERVOUS-SYSTEM

The central nervous system is one of the primary target organs for hydrogen sulphide (H2S) toxicity; however, there are limited data on the neurotoxic effects of low-dose chronic exposure on the developing nervous system. Levels of serotonin and norepinephrine in the developing rat cerebellum and frontal cortex were determined following chronic exposure to 20 and 75 ppm H2S during perinatal development. Both monoamines were altered in rats exposed to 75 ppm H2S compared with controls; serotonin levels were significantly increased at days 14 and 21 postnatal in both brain regions, and norepinephrine levels were significantly increased at days 7, 14, and 21 postnatal in cerebellum and at day 21 in the frontal cortex. Exposure to 20 ppm H2S significantly increased the levels of serotonin in the frontal cortex at day 21, whereas levels of norepinephrine were significantly reduced in the frontal cortex at days 14 and 21, and at day 14 in the cerebellum.