Neuropeptides in cerebrospinal fluid.
Most neuropeptides can now be assayed in human cerebrospinal fluid (CSF). Some, such as beta-endorphin and arginine vasopressin, seem to be secreted directly into CSF. Others may reach CSF from plasma either by passage through the blood-brain barrier or by absorption through the circumventricular organs, which lack a blood-brain barrier. The role of neuropeptides in CSF is still unclear. Thyrotropin-releasing hormone, somatostatin, arginine vasopressin, angiotensin II, substance P, vasoactive intestinal polypeptide, beta-endorphin, gastrin, and cholecystokinin are all present in assayable quantities in human CSF. Their functions in this fluid are liable to be as diverse as their functions elsewhere in the body. The release of hypothalamic releasing factors into the CSF may be part of the pathway of pituitary hormone release. Pituitary hormones may function in CSF as part of a feedback loop from the hypothalamus. Other neuropeptides may affect receptors in the central nervous system far away from their release site. Intraventricular neuropeptide injection, anatomical and physiological ablation experiments, receptor studies, and neurobiological techniques now being developed will allow a more complete understanding of CSF neuropeptide function in the future.
D000818:Animals; D001812:Blood-Brain Barrier; D004723:Endorphins / Q000134:cerebrospinal fluid; D006801:Humans; D009481:Neurophysins / Q000134:cerebrospinal fluid; D010455:Peptides / Q000134:cerebrospinal fluid* / Q000502:physiology; D010906:Pituitary Hormone-Releasing Hormones / Q000134:cerebrospinal fluid; D010908:Pituitary Hormones, Anterior / Q000134:cerebrospinal fluid; D014667:Vasopressins / Q000134:cerebrospinal fluid
D004723:Endorphins; D009481:Neurophysins; D010455:Peptides; D010906:Pituitary Hormone-Releasing Hormones; D010908:Pituitary Hormones, Anterior; D014667:Vasopressins