Date : 08.20.2010

Brain Lactate Regulates AVP Neurons through Interaction with ASICs

Category : Research Topic
 DEPARTMENT OF CELL PHYSIOLOGY, Division of Correlative Physiology

Arginine vasopressin (AVP), an anti-diuretic hormone, is released from AVP neurons, which exist mainly in the hypothalamic supraoptic nucleus (SON), when the body becomes dehydrated (hypertonic). Acid-sensing ion channels (ASICs) are neuronal cation channels that are activated by extracellular acidification. However, it has not been known whether and how ASICs are involved in the function of AVP neurons. In the present study, Dr. Toyoaki Ohbuchi and Prof. Yoichi Ueta in University of Occupational and Environmental Health obtained following new findings through collaboration with Ms Kaori Sato and Prof. Yasunobu Okada in National Institute for Physiological Sciences:

1) ASICs are molecularly and functionally expressed in rat AVP neurons.
2) Lactate activates ASIC currents in AVP neurons.
3) Hypertonic stress increases lactate production in the SON.

Thus, it is suggested that brain lactate, which is accumulated under ischemic or hypoxic conditions, plays an important role in the regulatory mechanism of body fluid homeostasis by augmenting AVP secretion through interaction with ASICs in AVP neurons.