Prostaglandins and n-3 polyunsaturated fatty acids in the regulation of the hypothalamic–pituitary axis

The hypothalamic–pituitary (H–P) axis integrates complex physiological and environmental signals and responds to these cues by modulating the synthesis and secretion of multiple pituitary hormones to regulate peripheral tissues. Prostaglandins are a component of this regulatory system, affecting multiple hormone synthesis and secretion pathways in the H–P axis. The implications of these actions are that physiological processes or disease states that alter prostaglandin levels in the hypothalamus or pituitary can impinge on H–P axis function. Considering the role of prostaglandins in mediating inflammation, the potential for neuroinflammation to affect H–P axis function in this manner may be significant. In addition, the mitigating effects of n-3 polyunsaturated fatty acids (n-3 PUFA) on the inflammation-associated synthesis of prostaglandins and their role as substrates for pro-resolving lipid mediators may also include effects in the H–P axis. One context in which neuroinflammation may play a role is in the etiology of diet-induced obesity, which also correlates with altered pituitary hormone levels. This review will survey evidence for the actions of prostaglandins and other lipid mediators in the H–P axis, and will address the potential for obesity-associated inflammation and n-3 PUFA to impinge on these mechanisms.