The Role of VACM-1 in Dehydration and Hemorrhage


Name: Thomas Ceremuga

Rank: MAJ, USA

Organization: Henry M. Jackson Foundation

Performance Site: Uniformed Services University of the Health Sciences, Bethesda, MD

Year Published: 2001

Abstract Status: Final


Altered states of fluid homeostasis, such as dehydration, hyperosmolarity, hemorrhage, and hypovolemia are conditions that can be devastating to the individual. The neuropeptide, arginine vasopressin (AVP), has a profound role in the maintenance of water or fluid balance in the body. Until recently, there have only been three AVP receptor subtypes identified, V1a, V1b, and V2. A fourth AVP receptor, Vasopressin Activating-Calcium Mobilization (VACM-1), has been discovered in numerous tissues of the rabbit. There is a large body of knowledge regarding the distribution, location, and physiologic roles of AVP and its older receptor subtypes; however, many unknowns remain pertaining to VACM-1. It is important to answer these questions regarding VACM-1, as it may provide scientific insight related to its localization and function, and its potential implications concerning fluid and water homeostasis. The central hypothesis of this proposed research is that the VACM-1 neuropeptide receptor is located in multiple areas of the brain involved with water homeostasis and blood pressure regulation. The specific aims of this research are:

  1. To discover the specific areas of the body (with the focus on the brain) that VACM-1 is located, and
  2. To investigate the physiologic functions and regulation of VACM-1 in environmental stressful conditions of dehydration, hyperosmolarity, hemorrhagic hypovolemia, and in the presence or absence of AVP.

The rationale for this proposed research is based on the lack of and inconsistent data characterizing this new AVP receptor subtype, VACM-1. Additionally, this receptor may have a significant role in states of altered water/fluid homeostasis. With results obtained from these experiments, we expect to gain a better understanding of AVP and its receptors involved in the body's response to altered fluid conditions at the molecular level, in vivo. This will provide insight and contribute to the development of new approaches and interventions that will improve care and treatment of imbalances of fluid homeostasis.


Final report is available on NTRL: