DHEA is transformed into DHEA-S by sulfation at the C3β position via the sulfotransferase enzymes SULT2A1 and to a lesser extent SULT1E1 .    This occurs naturally in the adrenal cortex and during first-pass metabolism in the liver and intestines when exogenous DHEA is administered orally. [ citation needed ] Levels of DHEA-S in circulation are approximately 250 to 300 times those of DHEA.  DHEA-S in turn can be converted back into DHEA in peripheral tissues via steroid sulfatase (STS).  
More importantly, let's focus on treatment! While there is currently no cure for feline asthma, treatment should include bronchodilators and glucocorticoids to reduce bronchoconstriction and airway inflammation. Bronchodilators, including methylxanthines like aminophylline and theophylline or beta-2 agonists like terbutaline can be administered to cats orally or parenterally. Beta-2 agonist albuterol therapy can also be administered by metered dose inhaler. Corticosteroids can also be administered orally, parenterally, or by metered dose inhaler. The most commonly used inhaled corticosteroid is fluticasone propionate. Fluticasone propionate is a synthetic corticosteroid that has 18-fold greater affinity for the corticosteroid receptor compared with dexamethasone, the reference standard for corticosteroid potency. Don't forget to use a space chamber like the Aerokat for administration. Your pet owners can buy these directly from Trudell or on Amazon .