HYPOTHALAMIC UPTAKE OF [TESTOSTERONE-H-3 IN CHICKENS DIFFERING IN MATING FREQUENCY

The uptake and retention of radioactive testosterone by hypothalamic tissues were measured in lines of chickens selected for high and low cumulative number of completed matings and in the unselected randombred population from which the selected lines originated. Tritiated testosterone was injected into five-week old cockerels in one of two ways: (a) as labelled testosterone in corn oil and (b) as labelled and unlabelled testosterone in corn oil. Birds were then sacrificed at either 30, 60, 120, or 240 min after injection. Radioactive testosterone uptake by blood and hypothalamic tissue expressed in disintegrations per min (dpm) was the measurement criterion. No significant differences were found between hormonal treatments or among lines for blood and hypothalamic dpm. These findings suggest that the behavioral differences among the lines are not due to differences in the ability of hypothalamic tissues to concentrate testosterone. © 1978.