Pineal Gland Culture.

Abstract

Pineal gland secretes the hormone melatonin at night with a circadian rhythm. The synthesis and secretion of melatonin are stimulated at night by norepinephrine released by sympathetic postganglionic neurons projecting from the superior cervical ganglia. Norepinephrine simultaneously activates α- and β-adrenoceptors, triggering melatonin synthesis.To study the regulation of melatonin production and secretion, it is very convenient to use an ex vivo preparation. Thus, it is possible to keep intact pineal glands in culture and to study the actions of agonists, antagonists, modulators, toxic agents, etc., in melatonin synthesis. Artificial melatonin synthesis stimulation in vitro is usually achieved by using a β-adrenergic agonist alone or in association with an α-adrenergic agonist. In this chapter, the methodology of cultured pineal glands will be described. Several papers were published by our group using this methodology, approaching the role played in melatonin synthesis control by angiotensin II and IV, insulin, glutamate, voltage-gated calcium channels, anhydroecgonine methyl ester (AEME, crack-cocaine product), monosodium glutamate (MSG), signaling pathways like NFkB, pathophysiological conditions like diabetes, etc.