Physiologic control of two neurophysins in humans

Area of Science:

• Neuroendocrinology
• Human Physiology
• Hormone Assays

Background:

• Neurophysins are carrier proteins for neurohypophyseal hormones.
• Two human neurophysins, nicotine stimulated neurophysin (NSN) and estrogen stimulated neurophysin (ESN), have been identified.
• Their physiological roles and associations with specific hormones require further elucidation.

Purpose of the Study:

• To assay NSN and ESN levels in humans under various physiological and pathological conditions.
• To investigate the potential associations of NSN with vasopressin and ESN with oxytocin.

Main Methods:

• Assaying human neurophysin levels (NSN and ESN) during physiological maneuvers and pathological states.
• Observing neurophysin responses to stimuli such as volume depletion, surgical stress, dehydration, and hormone administration.

Main Results:

• NSN levels were elevated in response to potent vasopressin-releasing stimuli like volume depletion, surgical stress, hypotension, and hypertonic saline.
• NSN did not consistently elevate with dehydration and showed varied responses in the syndrome of inappropriate antidiuretic hormone secretion.
• ESN levels increased during estrogen administration, pregnancy, in newborns, and in patients with cirrhosis, and acutely at parturition.

Conclusions:

• Data support the association of NSN with vasopressin, particularly under potent release stimuli.
• ESN may be associated with oxytocin, but further research on human oxytocin physiology is needed for confirmation.
• Neurophysin assays provide insights into neurohypophyseal hormone regulation in health and disease.