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Renal afferent nerve stimulation induces baroreflex resetting through the activation of sympathorenal axis without compromising arterial pressure buffering function
Author(s) -
Tobushi Tomoyuki,
Hosokawa Kazuya,
Murayama Yoshinori,
Saku Keita,
Onitsuka Ken,
Sakamoto Takafumi,
Sakamoto Kazuo,
Fujino Takeo,
Ikeda Masataka,
Kakino Takamori,
Ide Tomomi,
Sunagawa Kenji
Publication year - 2012
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.26.1_supplement.872.34
Subject(s) - baroreflex , carotid sinus , medicine , denervation , stimulation , mechanosensitive channels , blood pressure , anesthesia , chemistry , cardiology , heart rate , receptor , ion channel
Background Chronic kidney disease is known to induce sympathoexcitation, and nephrectomy of those kidneys results in sympathoinhibition. Recent clinical trials indicated that renal nerve ablation markedly suppressed sympathetic nerve activity (SNA). Since the baroreflex system is a powerful regulator of SNA, we examine how renal afferent innervation impacts on baroreflex function to clarify the pathophysiological significance of sympathorenal axis. Methods : In 8 anesthetized rats, we isolated the bilateral carotid sinuses and controlled intra sinus pressure (ISP). We dissected the unilateral renal afferent nerve for electrical stimulation (STM) and measured contralateral splanchnic SNA. We changed ISP from 60 to 180 mmHg stepwise with/without STM and measured arterial pressure (AP) and SNA. Results : STM significantly upward‐shifted the sigmoidal ISP‐SNA relationship (ΔSNA=21.2±2.6%, p<0.01) without changing the maximum gain (1.4±0.8 vs. 1.6±0.8, p=NS) or response range (77.9±16 vs. 95.3±52 mmHg, p=NS). The estimated setpoint pressure increased from 188.7±16.3 to 214.2±13.9 mmHg (p<0.05). STM did not change the SNA‐AP relationship. Conclusion : STM induces baroreflex resetting through the activation of sympathorenal axis. The fact that the baroreflex gain remains unaltered suggests that the renal deafferentiation by ablation lowers AP without compromising AP buffering function.