Central and peripheral interleukin-1beta and interleukin-1 receptor I expression and their role in the acute stress response of common carp, Cyprinus carpio L.

In fish, the hypothalamus-pituitary-interrenal axis (HPI-axis), the equivalent of the hypothalamus-pituitary-adrenal axis (HPA-axis) in mammals, is activated during stress and leads to production and release of cortisol by the interregnal cells in the head kidney. In mammals, the cytokine interleukin-1beta (IL-1beta) takes a key position in the innate immune and inflammatory responses and influences the HPA-axis. In fish, studies that address the effects of cytokines on HPI-axis activation are limited.