Dopamine Secretion from the Isolated Perfused Sheep Adrenal

Isolated sheep adrenals, perfused with Tyrode solution, release in addition to adrenaline (A) and noradrenaline (NA) small amounts of dopamine (DA) into the effluent. The amines appeared in the perfusate even in the absence of C1 or Ca 2+ ions. Addition of ACh to the per‐fusion fluid increased NA and A in the effluent 2–3 times and DA about 5 times. In calcium and chloride free Tyrode solution carbachol increased secretion 1.7–2.7 times for all 3 amines. Reintroduction of Ca 2+ into the media increased the response to ACh and carbachol 5–7 times. Injection of Ca 2+ into the perfusion fluid further increased the secretory response to simultaneously added. ACh and carbachol 14–18 times for all 3 amines.