Increased blood pressure in nesfatin/nuclebindin-2-transgenic mice

Area of Science:

• Neuroendocrinology
• Cardiovascular Physiology
• Renal Physiology

Background:

• Nesfatin/nucleobindin-2 (nesf/NUCB2) is a precursor to the anorexigenic protein nesfatin-1.
• nesf/NUCB2 is expressed in hypothalamic nuclei regulating the autonomic nervous system.

Purpose of the Study:

• To investigate the role of nesf/NUCB2 in blood pressure and ingestive behavior regulation.
• To utilize nesf/NUCB2-transgenic (Tg) mice to study these effects.

Main Methods:

• Measurement of blood pressure and heart rate in conscious and anesthetized Tg and non-Tg mice.
• Assessment of 24-hour water intake and urine volume using metabolic cages.
• Analysis of kidney weight and mRNA expression of epithelial sodium channel (ENaC)-α and ENaC-γ in the hypothalamus and kidney via real-time PCR.

Main Results:

• Tg mice exhibited significantly higher systolic, diastolic, and mean blood pressure, but not pulse rate, when conscious.
• Anesthesia abolished the elevated blood pressure in Tg mice.
• Tg mice showed increased water intake and urine volume, with lower urine sodium concentration but unchanged serum sodium and urine sodium excretion.
• Kidney weight was increased in Tg mice, with decreased hypothalamic ENaC-γ mRNA expression.

Conclusions:

• Nesf/NUCB2 plays a role in the central regulation of blood pressure.
• The findings suggest a brain-mediated mechanism involving nesf/NUCB2 in blood pressure control.