Modifying a displacement pump for oral gavage dosing of solution and suspension preparations to adult and neonatal mice.

To assess a drug's toxic or carcinogenic effects on neonatal and adult mice and rats, researchers often carry out oral gavage studies. Whether dosed singly or in various combinations, provided as soluble solutions or as colloidal suspensions, the drug must be delivered in accurate and precise doses. For studies that require newborn mice to receive multiple daily doses, delicately handling neonates to increase their chances of surviving is just as critical as the ability to accurately dose small volumes.

Frequency of Hprt mutant lymphocytes and micronucleated erythrocytes in p53-haplodeficient mice treated perinatally with AZT and AZT in combination with 3TC.

Azidothymidine (AZT) is a nucleoside reverse transcriptase inhibitor (NRTI) that is used for reducing mother-to-child transmission of human immunodeficiency virus I. Combinations of AZT and 3'-thiacytidine (3TC) are even more effective than AZT alone. AZT, however, is a mutagen and carcinogen in rodent models and 3TC can increase the genotoxicity of AZT.