sodium-nitrite and diisopropanolamine

The carcinogenic activity of endogenously synthesized N-nitroso-bis(2-hydroxy-propyl)amine (NDHPA) was investigated in male Wistar rats administered bis(2-hydroxypropyl)amine (DHPA), mixed into a powdered diet at a concentration of 1%, and NaNO2 dissolved in distilled water at concentrations of 0.15% and 0.3%, for 94 weeks. Urinary excretion of NDHPA clearly demonstrated its endogenous synthesis in rats given 1% DHPA and 0.3% NaNO2, but not in the groups receiving either of these precursors alone. Tumours of the nasal cavity, lung, oesophagus, liver and urinary bladder were found in rats treated with 1% DHPA and 0.15% or 0.3% NaNO2. The incidences of nasal cavity and lung tumours reached 74% and 58% respectively, in rats given 1% DHPA and 0.3% NaNO2. The tumour distribution was almost the same as that seen in rats given NDHPA. These results indicate that endogenously synthesized NDHPA has similar carcinogenic activity to exogenously administered NDHPA in rats.

Topics: Animals; Carcinogens; Male; Neoplasms, Experimental; Nitrosamines; Propanolamines; Rats; Rats, Inbred Strains; Sodium Nitrite

The carcinogenic activity of endogenously synthesized N-nitrosobis(2-hydroxypropyl)amine (BHP) was investigated in male Wistar rats administered bis(2-hydroxypropyl)amine (BHPA) mixed in powder diet at a concentration of 1%, and sodium nitrite (SN) dissolved in distilled water at concentrations of 0.15 and 0.3%, for 94 weeks. Urinary excretion of BHP was detected in rats given 1% BHPA and 0.3% SN but not in the groups receiving either of these precursors alone. Nasal cavity, lung, esophagus, liver and urinary bladder tumors were found in animals treated with combinations of 1% BHPA and 0.15 or 0.3% SN, suggesting that the target organs of the endogenously synthesized BHP are similar to those affected when the carcinogen is administered exogenously. The incidences of nasal cavity and lung tumors reached 74 and 58% in rats given 1% BHPA and 0.3% SN, respectively. Tumors at sites other than target organs were only found at levels similar to those previously reported for spontaneous tumors in male Wistars. The present results clearly indicated the tumor inducibility of a nitrosatable amine, BHA, through an endogenous nitrosation by feeding to rats in conjunction with nitrite, and provide further suggestive evidence that endogenous nitrosations of environmental nitrosatable amines can be a potential risk factor in human cancer development.

Topics: Animals; Biotransformation; Carcinogens; Male; Neoplasms, Experimental; Nitrites; Nitrosamines; Propanolamines; Rats; Rats, Inbred Strains; Sodium Nitrite; Tissue Distribution