Biological behavior of 67Ga-citrate in New Zealand White rabbits

The pharmacokinetics, protein binding, excretion and tissue distribution of ⁶⁷Ga after the administration of ⁶⁷Ga-citrate to New Zealand White rabbits is described. Data for ⁶⁷Ga blood levels were best described by an equation with three exponential components exhibiting half lives of 0.25 h, 7.4 h and 19.5 h, with almost all of the activity in a protein bound form. Weekly urinary excretion ( 27%), possibly in a metabolized form, and fecal elimination (20%) were greater than the reported values in man, but there was a similar organ distribution pattern in these animals as in man. The overall biological handling was judged to be similar in both species making the rabbit a suitable model for further ⁶⁷Ga-citrate studies in vivo.