Male Wistar-Imamichi (W-I) and BN rats were placed under the various intensity of illumination (10,100 and 1000 1ux). Lighting cycle was LD=12 : 12 (6 : 00 lights on). Present study leads the following results.
(1) Ambulatory activity of W-I was affected by the intensity of illumination. However, this effect was rather small in BN rats. It was observed to higher ambulatory activity during lighting period in the group of W-I under the 10 lux. Except this phenomenon, there was no difference in the daily behavioral rhythm pattern of ambulatory activity under the various intensity of illumination in the both rat strain.
(2) In pentobarbital sodium 50mg/kg i.p.injection to W-I and BN at 9 : 00 and 18 : 00, there was no difference in the anesthetic effect among the three groups under the various intensity of illumination. However, anesthetic effect lasted longer in the rats of 9 : 00 PB injiection than that of 18 : 00 injection
(3) In cocaine 10mg/kg s.c.injection to the both strain at 9 : 00, the strongest acute effect was observed under the 10 lux.
(4) In W-I strain, acute effect of cocaine injection at 18 : 00 continued longer than that at 9 : 00. In W-I,the strongest acute effect was observed under the 10 lux. However, acute effect was least under the 10 lux in BN.
(5) Biochemical analysis was done with blood taken at 9,12,18,21 and 24 : 00 under the various intensity of illumination. There were some differences in the level of total protein, glucose, GTP et al due to the different intensity of illumination.