What is the effect of beta agonists on surfactant secretion by Type II alveolar cells?

• A. Increase secretion
• B. Decrease secretion
• C. No effect
• D. Completely inhibit synthesis

Answer: (B)

Beta-adrenergic stimulation prompts Type II alveolar cells to release surfactant by raising intracellular cAMP through beta-2 receptor activation. This signaling triggers exocytosis of lamellar bodies, increasing surfactant in the alveolar space. The immediate effect is enhanced secretion, while surfactant synthesis itself is more influenced by glucocorticoids over longer periods. So the net effect of beta agonists is an increase in surfactant secretion, not a decrease or no effect.