Elevated plasma vasopressin in cardiomyopathic hamsters

Area of Science:

• Cardiovascular Physiology
• Endocrinology
• Heart Failure Research

Background:

• BIO 14.6 strain hamsters develop age-related cardiomyopathy and heart failure.
• Elevated plasma arginine-vasopressin (AVP) is observed in these animals.
• AVP levels appear inappropriately high given the animals' hydration and blood pressure status.

Purpose of the Study:

• To investigate the role of elevated arginine-vasopressin (AVP) in the cardiovascular state of myopathic hamsters.
• To determine if AVP contributes to elevated vasomotor tone in heart failure.
• To explore potential therapeutic targets for heart failure.

Main Methods:

• Comparison of plasma AVP levels between BIO 14.6 hamsters and a control strain.
• Intravenous administration of a specific AVP antagonist [d(CH2)5Ome(TYR)AVP].
• Measurement of arterial pressure changes in response to AVP antagonist and vehicle.

Main Results:

• Plasma AVP levels were approximately 2-fold higher in 11-month-old BIO 14.6 hamsters compared to controls.
• AVP antagonist administration caused a significant fall in arterial pressure in myopathic hamsters.
• The AVP antagonist had no effect on arterial pressure in control hamsters, and vehicle had no effect in either strain.

Conclusions:

• Inappropriately elevated arginine-vasopressin (AVP) contributes to the cardiovascular state in myopathic hamsters.
• AVP may play a role in maintaining elevated vasomotor tone during heart failure.
• These findings suggest AVP as a potential factor in human congestive heart failure.