Phenotype of the obese Koletsky (f) rat due to Tyr763Stop mutation in the extracellular domain of the leptin receptor (Lepr): evidence for deficient plasma to CSF transport of leptin in both the Zucker and Koletsky obese rat - Wu-Peng,S.; Chua,S.C.; Okada,N.; Lui,S.M.; Nicolson,M.; Leibel,R.L. (Diabetes, 1997)