We suggest that the adrenal medullary membrane undergoes nonpropagated electrotonic depolarization on electrical stimulation and thereby voltage-dependent Ca2+ channels are opened to initiate secretion. Catecholamine secretion is unaffected by tetrodotoxin or hexamethonium/atropine but is abolished by Ca2+ lack or 3 mM Mn2+. The adrenal glands are located just above the. The body produces them in the brain, nerve tissues, and adrenal glands.
The secretion is directly related to the strength and duration of the applied stimulus over a wide range. Catecholamines are hormones that also function as neurotransmitters. We demonstrate here that a single electrical shock to the perfused adrenal gland of the rat results in massive secretion of epinephrine and norepinephrine. Our aim was to see whether the same experimental technique could be used to directly excite the adrenal medullary cell membrane by electrical stimulation and whether such stimulation would result in secretion of catecholamines. The secretion is due to activation of cholinergic receptors of the adrenal medulla by acetylcholine released from splanchnic nerve terminals after transmural stimulation.
Transmural stimulation of the isolated adrenal gland of the rat and guinea pig results in secretion of catecholamines.
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