Nonsecretion

Nonsecretion is the state in which secretory activity is absent or markedly reduced in a gland or secretory cell. It can involve exocrine secretions released onto surfaces or ducts, or endocrine secretions released into the bloodstream. The term is used to describe a lack of normal secretory output rather than a qualitative change in the substance produced.

Causes and mechanisms of nonsecretion are diverse. They include absence or insensitivity to secretagogues (hormonal or neural stimuli), inhibition of the cellular exocytosis machinery, genetic or structural defects in the secretory pathway (such as problems with endoplasmic reticulum or Golgi processing, vesicle formation, or SNARE-mediated fusion), physical obstruction of ducts, and loss of secretory cells due to inflammation, autoimmune destruction, or atrophy. Drugs or systemic conditions that suppress secretion can also produce nonsecretion.

In medical contexts, nonsecretion can affect multiple organ systems. Autoimmune diseases like Sjögren's syndrome reduce lacrimal and salivary secretions, leading to dry eyes and dry mouth. Obstruction or destruction of exocrine tissues can impair pancreatic, biliary, or gastric secretions. Endocrine glands may exhibit reduced hormone release in certain diseases. Nonsecretion may be partial or complete and can be acute or chronic, depending on the underlying cause.

Diagnosis and management rely on identifying the cause and assessing the functional loss. Secretory tests (such as saliva or tear flow measurements, pancreatic enzyme tests, or gastric secretion studies), imaging, and histology can help. Treatments focus on addressing the underlying condition and replacing or compensating for lost secretions where feasible, for example through substitutes, enzyme replacement, or stimulation when possible.