Transplacental effects of ethylnitrosourea precursors ethylurea and sodium nitrite in hamsters

Abstract

Four simultaneous dosages of the ethylnitrosourea precursors, ethylurea and sodium nitrite, were administered intragastrically to pregnant hamsters at 100 mg/kg and 50 mg/kg respectively, from the 12-15th days of pregnancy. The treatment induced multiple neurogenic tumors of the peripheral nervous system in the offspring. Female progeny developed a greater incidence and multiplicity of peripheral nervous system tumors with significantly shorter latencies than males, thus establishing evidence that the tumors were age and sex dependent. The tumors presented varied morphological patterns and upon transplantation, grew regularly, exhibiting their malignant nature. The possible influence of estrogenic hormones on the development and growth of peripheral nervous system tumors and comparative aspects of the relationship between prenatal and postnatal carcinogenesis with regard to the ensuing tumor spectra as a consequence of exposure to the same chemical agent, are discussed.

Nerve growth factor and neural oncology

“…The same results may be observed by treatment with a single dose of ENU administered intravenously, intraperitoneally, subcutaneously, intracerebrally, intraarterially, or by stomach tube; multiple smaller doses; or intragastric administration of the components, ethylurea and sodium nitrite (26,27,34,35,36,38,53,68,83,84,114,143,144). The formation of ENU from ethylurea and sodium nitrite occurs rapidly in the acidic conditions of the stomach (109,110), and is catalyzed by sulfate and phosphate ions (109) and prevented by ascorbic acid (71).…”

“…Mice develop a much broader spectrum of tumors following ENU treatment than do rats (29,137,170). ENU is also carcinogenic to hamsters (143,144), rabbits (46), dogs ( I IS), opposums (73), and many other vertebrate species.…”