Separation of the nucleus from the cytoplasm of frog, chicken and trout erythrocytes by means of high doses of vitamin B12.

The effect of high doses vitamin B12 on the nucleus-bearing erythrocytes in the peripheral blood of the frog, chicken and trout has been investigated. The i.p. and i.m. injection of 5 mg B12/animal, caused the separation of the nucleus from the cytoplasm of the erythrocytes to various degrees. The most pronounced effect was observed in trouts, where 75% of the erythrocytes lost their cytoplasm. Frog and chicken were less susceptible to the denucleating effect of B12. About 10-15% of the frog and chicken erythrocytes lost their cytoplasm 7-8 weeks after the B12 injection.