Amplified respiratory-sympathetic coupling in the spontaneously hypertensive rat: Does it contribute to hypertension?

Abstract

Sympathetic nerve activity (SNA) is elevated in established hypertension. We tested the hypothesis that SNA is elevated in neonate and juvenile spontaneously hypertensive (SH) rats prior to the development of hypertension, and that this may be due to augmented respiratory-sympathetic coupling. Using the working heart-brainstem preparation, perfusion pressure, phrenic nerve activity and thoracic (T8) SNA were recorded in male SH rats and normotensive Wistar-Kyoto (WKY) rats at three ages: neonates (postnatal day 9-16), 3 weeks old and 5 weeks old. Perfusion pressure was higher in SH rats at all ages reflecting higher vascular resistance. The amplitude of respiratory-related bursts of SNA was ..