Panel A shows the results of an experiment of Stojilkovic et al. in which rat pituitary cells were exposed to two 30 minute pulses of 100 nM GnRH at one hour intervals. Panel B shows the response of the present model to the same pulses. If, how-ever, the rate of recovery of the calcium channels in the outer membrane is increased from v2 = 0.002 min-1 to v2 = 0.02 min-1 and the rate internalization of receptors is decreased from k11 = 0.08/n nM-1·min-1 to k11 = 0.04/n nM-1·min-1, then the present model gives responses (Panel C) similar to the exerperimental results in Panel A. The ordinate units for Panels B and C are ng.