Aggressive behavior in mice provokes a marked increase in both plasma epidermal growth factor and renin.

The plasma concentration of epidermal growth factor (EGF) in normal, nephrectomized and sialectomized mice is about 0.5 nmol/l. Aggressive behaviour results in a parallel increase in both plasma EGF and plasma renin for both normal and nephrectomized mice. The plasma concentration of EGF increases around 300- and 150-fold respectively; no increase is observed in sialectomized mice, suggesting that the submaxillary gland is an important source of liberated EGF. Virtually all the EGF is found in plasma as a low molecular species that behaves as pure EGF, when examined by radioimmuno- and radioreceptor assays.