Pituicyte

Pituicyte

Pituicytes are specialized glial cells found in the posterior pituitary gland. They play a crucial role in the functioning of the neurohypophysis, which is responsible for the storage and release of hormones such as oxytocin and vasopressin (also known as antidiuretic hormone, or ADH). Pituicytes are analogous to astrocytes in the central nervous system and are involved in supporting the neurons that project from the hypothalamus to the posterior pituitary.

Structure

Pituicytes are characterized by their star-shaped morphology, similar to astrocytes. They contain numerous processes that extend to the capillaries and the axon terminals of the hypothalamic neurons. These processes help in the regulation of hormone release by modulating the access of the axon terminals to the blood vessels.

Function

The primary function of pituicytes is to support the neurosecretory cells of the posterior pituitary. They help in the storage and release of hormones by:

• Regulating the extracellular environment
• Modulating the release of hormones in response to physiological stimuli
• Providing structural support to the axon terminals of hypothalamic neurons

Pituicytes also play a role in the reuptake and recycling of neurotransmitters, similar to the function of astrocytes in the central nervous system.

Clinical Significance

Dysfunction or damage to pituicytes can lead to various disorders related to hormone imbalance. For example, insufficient release of vasopressin can result in diabetes insipidus, a condition characterized by excessive thirst and urination. Conversely, overproduction of vasopressin can lead to syndrome of inappropriate antidiuretic hormone secretion (SIADH), which causes water retention and hyponatremia.

Related Pages

• Posterior pituitary gland
• Neurohypophysis
• Oxytocin
• Vasopressin
• Hypothalamus
• Astrocyte
• Diabetes insipidus
• Syndrome of inappropriate antidiuretic hormone secretion