Stress-induced sensitization and glucocorticoids. II Sensitization of the increase in extracellular dopamine induced by cocaine depends on stress-induced corticosterone secretion. The background image on this page is an illustration of Camellia Thea, tea, from Kohler's Medicinal Plants. It is used with the kind permission of The Missouri Botanical Garden. The original image can be found here .
Tea is a major source of the xanthines caffeine and theophylline.
They also increase heart rate and myocardial force of contraction, and they increase the release of catecholamines from the adrenal medulla. Theophylline is widely used both orally or intravenously in the treatment of asthma and bronchospasm.