An in vivo model for pharmacokinetic studies in the kidney

In order to assess drug renal kinetics in vivo, the two kidneys of seven ewes were surgically placed under the skin. Through the use of renal function tests and a series of biopsies, we found that the kidneys remained normal in their subcutaneous location. Gentamicin renal kinetics were evaluated in conscious animals by a series of biopsies. Histological controls showed only slight lesions due to biopsy; based upon plasma hydrocortisone concentration, there was no indication of chronic stress affecting the renal pharmacokinetics. We suggest that this model has great potential as a method for studying in vivo the kinetics of drug disposition in the renal tissue and assessing the residue level of a drug.