Evaluation of the oral toxicity of spinacine hydrochloride in a 13-week study in rats.

Spinacine (4,5,6,7-tetrahydro-1H-imidazo[4,5-c]pyridine-6-carboxylic acid), the major reaction product of formaldehyde added to Grana Padano cheese, was administered to five groups of ten rats of each set at dietary concentrations that provided doses of O (control), 15, 30, 60 or 300 mg/kg body weight/day for 13 wk. There were no adverse effects upon survival, growth or food intake. No significant treatment-associated changes were found in haematological parameters, in serum chemistry or organ weights at the end of the study. At autopsy, neither gross nor histological modifications were attributable to treatment with spinacine. In this study the no-effect dose level for spinacine was considered to be 300 mg/kg body weight/day.