What effect do anticholinergic agents have on secretory glands?

Anticholinergic agents primarily block the action of acetylcholine, a neurotransmitter that plays a crucial role in stimulating secretory glands. By inhibiting this action, anticholinergic drugs lead to a reduction in glandular secretions. This is particularly notable in salivary glands, where decreased secretion can result in symptoms such as dry mouth, also known as xerostomia. This effect is why anticholinergic agents can be used therapeutically to mitigate excessive secretions in conditions like chronic obstructive pulmonary disease (COPD) or to relieve sialorrhea (excessive salivation).

The other options do not accurately describe the physiological impact of anticholinergic agents on secretory glands. For example, while it might be intuitive that glands could swell due to excessive stimulation, anticholinergic agents actually reduce activity rather than increase it or have no effect. This reduction in function is a hallmark of their pharmacological profile, leading to the specific symptomatology associated with their use. Thus, noting that these agents decrease glandular secretions leading to dry mouth captures the essence of their action on secretory glands effectively.