Gestational age and dose influence on placental transfer of ⁶³Ni in rats

Radioactive concentrations detected in placentas and fetuses on GD 12, 15 and 20 in rats injected respectively with various doses of ⁶³Ni for 24h. (A) The significant increases of ⁶³Ni concentrations in placentas depended upon the dose and the gestational age. (B) The significant increases of ⁶³Ni concentrations in fetuses 24h after three doses injections were shown in a dose-dependent manner on each GD tested. However, in all three dose groups, ⁶³Ni concentrations in fetuses increased markedly from GD 12 to 15, but decreased moderately on GD 20. Bars indicate mean±SEM, *p<0.05, **p<0.01, ***p<0.001.

The photograph (A) and autoradiograph (B, glass plate coated with nuclear emulsion, exposure time=4 weeks) of a placenta on GD 20 in rat injected with the dose of 640kBq/kg body weight of ⁶³Ni for 24h. The radioactivity is only concentrated within the basal lamina of placenta. Bar=2mm.

Representative autoradiograph of fetal sagittal section (640kBq/kg weight of ⁶³Ni administration on GD 20 in rat for 24h) exposed to roentgen film for 4 months. It shows intensive radioactivity located in bones including frontal, parietal, occipital, sphenoidal bone and vertebrae, clavicle, scapula, costal cartilage, elbow-bone, radial bone, humerus and femur and the organs including heart, liver, kidney, eye, lung and intestine. Bar=5mm.

Representative photographs and autoradiographs (glass plate coated with nuclear emulsion, exposure time=4 weeks) of the 6th, 7th and 8th cervical vertebras (A), the 7th, 8th and 9th costal cartilages (B), tibia (C) and parietal bone (D) in fetuses on GD 20 in rats injected with the dose of 640kBq/kg body weight of ⁶³Ni for 24h. Bar=500μm (A, B, C) and 200μm (D).

Radioactive concentrations of ⁶³Ni detected in amniotic fluid (A) and fetal membranes (B) on GD 12, 15 and 20 in rats injected intraperitoneally with different doses of ⁶³Ni for 24h. Bars indicate mean±SEM, *p<0.05, **p<0.01, ***p<0.001.

Radioactive concentrations of ⁶³Ni in maternal blood (A) and kidney (B) on GD 12, 15 and 20, in fetal blood (A) and kidney (B) on GD 20 in rats injected intraperitoneally with different doses of ⁶³Ni for 24h. Bars indicate mean±SEM, *p<0.05, **p<0.01, ***p<0.001.

The photograph (A) and autoradiograph (B, glass plate coated with nuclear emulsion, exposure time=4 weeks) of a maternal kidney on GD 20 in rat injected with the dose of 640kBq/kg body weight of ⁶³Ni for 24h. The radioactivity locates primarily in renal cortex, partially in renal medulla and blood vessel. Bar=2mm.