Ulcerogenic cinchophen induces c-Fos expression in CRH-secreting cells in the PVH of rat brain

THIS study aimed at obtaining evidence that cinchophen, an ulcerogenic drug, stimulates the corticotropin-releasing hormone (CRH)-secreting cells in the paraventricular nucleus of the hypothalamus (PVH) to induce c-Fos expression. Without colchicine pretreatment, cinchophen was injected i.p. 60 min before the time of maximum CRH level in the hypothalamus, as decided by radioimmunoassay. Eighty percent of the c-Fos/CRH double-labelled cells were concentrated in the parvicellular subnuclei. In the medial and anterior parvicellular subnuclei, the double-labelled neurones of treated rats significantly outnumbered those of controls. The result shows that cinchophen induces excitation of the CRH-secreting cells.