CHANGES IN CERTAIN HEMATOLOGICAL AND PHYSIOLOGICAL VARIABLES FOLLOWING SINGLE GALLIUM-ARSENIDE EXPOSURE IN RATS

Gallium arsenide (GaAs), a group III-VA intermetallic semiconductor, p ossesses superior electronic and optical properties and has a wide app lication in electronic industry. Exposure to GaAs in the semiconductor industries could be a possible occupational risk. The aim of the pres ent study was to determine the dose-dependent effect of single oral ex posure to GaAs (500, 1000, or 2000 mg/kg) on some biochemical variable s in heme synthesis pathway and few selected physiological variables a t d 1, 7, and 15 following administration. The results indicate that G aAs produced a significant effect on the activity of delta-aminolevuli nic acid dehydratase (ALAD) in blood and heart (particularly at d 7) f ollowing exposure to 2000 mg/kg, whereas urinary delta-aminolevulinic acid (ALA) excretion was elevated only at d 7. No marked influence of GaAs on blood hemoglobin, zinc protoporphyrin, and packed cell volume was noticed. Blood glutathione (GSH) was significantly reduced at d 7, but remained unchanged at two other time intervals. On the other hand , heart GSH contents remained uninfluenced on GaAs exposure. Most of t he physiological variables, viz. blood pressure, heart and respiration rate, and twitch response, remained unchanged, except for some minor alterations observed at d 7 and 15 following exposure to GaAs at a dos e of 2000 mg/kg. Blood gallium concentration was not detectable in nor mal animals and rats exposed to 500 mg/kg GaAs. Blood arsenic concentr ation was, however, detectable even at the a lower dose level and incr eased in a dose-dependent manner. All these changes showed a recovery pattern at d 21, indicating that the alterations are reversible.