the increase , expressed as a percentage of the control value , in the area of smooth endoplasmic reticulum ( er ) per unit cytoplasmic volume did not differ between periportal and perivenular hepatocytes in 10-day-old mice injected with 50 mg/kg phenobarbital ( pb ) at 7 , 8 , and 9 days of age , whereas it was greater in perivenular than in periportal hepatocytes in 20-day-old animals injected with 100 mg/kg at 17 , 18 , and 19 days of age .
C0230789
smooth endoplasmic reticulum
C0010834
cytoplasmic