Orgаnоphоsphаtes аre cоmmonly used pesticides, such as malathion and parathion. However, there are health concerns about their use since high doses of organophosphates will result in overstimulation of the parasympathetic nervous system. What would be the potentially harmful effects of organophosphate poisoning? OR Adrenocorticotropic hormone (ACTH) is a hormone released by the anterior pituitary that stimulates the adrenal cortex to produce cortisol. ACTH is very similar to another hormone, Melanocyte stimulating hormone (MSH), such that if ACTH levels are increased, levels of MSH will also increase resulting in dark patches on the skin (hyperpigmentation.) It is found that administering extra cortisol results in lowered ACTH levels, and alleviates the hyperpigmentation. Why would extra cortisol have this effect?