Assessing the potential leukemogenic effects of 50 Hz magnetic fields and their harmonics using an animal leukemia model.

To answer the still unresolved question of the possible leukemogenic effects of extremely low frequency magnetic fields (ELF-MFs) and of their harmonics on the incidence of B acute lymphoblastic leukemia in children, we used an animal model to explore the possible co-initiating or co-promoting effects of ELF-MFs on the development of leukemia. We used a rat model in which B acute lymphoblastic leukemia is chemically induced by a nitrosurea derivative. From the onset of the chemical treatment, the animals were also exposed to ELF-MFs (100 microT, sinusoidal 50 Hz MFs), with or without harmonics.

A new model of pre-B acute lymphoblastic leukemia chemically induced in rats.

Objective: Although B acute lymphoblastic leukemia (B-ALL) is the most common leukemia among children, no chemically inducible model of this leukemia has yet been described in vivo.

Methods: Leukemia was chemically induced in male WKAH/Hkm rats by a nitrosourea derivative, N-butylnitrosourea (BNU), an alkylating agent, administered orally 5 days a week for 24 weeks. Development of leukemia was monitored by clinical observation, follow-up of blood parameters, and appearance of blast cells in peripheral blood samples.

The Arg617-Arg618 cleavage site in the C-terminal domain of PC1 plays a major role in the processing and targeting of the enzyme within the regulated secretory pathway.

The C-terminal domain of the prohormone convertase PC1 is involved in targeting of the enzyme to secretory granules in neuroendocrine cells and is subsequently processed in this compartment at an Arg617-Arg618 site. Three other dibasics are found in the C-terminal domain of mouse PC1. Here, we examined the role of the four dibasics in targeting PC1 to secretory granules.