Pharmacokinetic study of recombinant human epidermal growth factor in the anterior eye

This study investigated the pharmacokinetics of recombinant human epidermal growth factor (EGF) in the eyes of live rabbits and enucleated human eyes. After intracameral injection of 1.2 muCi (1.1 micrograms) of 125I-EGF into rabbit eyes, tissues in the anterior segment were analyzed for uptake of 125I-EGF after 1, 2, 4, and 24 hr. The half-life of EGF during the initial 4 hr was 1.3 +/- 0.6 hr (+/- the confidence limit at P = 0.05) in the cornea, 0.7 +/- 0.4 hr in the iris, 1.9 +/- 0.9 hr in the lens, and 0.6 +/- 0.5 hr in the aqueous humor (n = 18 for each tissue). Between 4-24 hr, the percent retention of EGF in the tissues (relative to the initial amount in respective tissue) is in the order of lens greater than cornea greater than iris greater than aqueous humor. The kinetics of EGF uptake by excised human corneas was determined by incubating the endothelial surface with 1.2 muCi/ml (100 ng/ml) of 125I-EGF for 4 hr at 37 degrees C or 4 degrees C. After 4 hr, the total amount of EGF accumulated in the corneas was 2.3 +/- 0.2 ng (+/- standard deviation; n = 6) at 37 degrees C, and 1.4 +/- 0.1 ng at 4 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)