HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 91/1/111    most recent expphysiol.2005.031666v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Koba, S. Articles by Hayashi, N. Search for Related Content PubMed PubMed Citation Articles by Koba, S. Articles by Hayashi, N. Related Collections Themed Issue papers Cardiovascular control

¹ Graduate School of Engineering Science² School of Health and Sport Sciences, Osaka University, Toyonaka, Japan ³ Institute of Health Science, Kyushu University, Kasuga, Japan

We investigated the role played by the exercise pressor reflex in sympathetic regulation of the renal circulation in rats. In mid-collicular decerebrate rats, mean arterial pressure (MAP), heart rate (HR), left renal cortical blood flow (RCBF) and left renal sympathetic nerve activity (RSNA) were recorded before and during 30 s of static contraction of the left triceps surae muscles evoked by electrical stimulation of the tibial nerve, which activates both metabo- and mechanosensitive muscle afferents, and during 30 s of passive stretch of the left Achilles tendon, which selectively activates mechanosensitive muscle afferents. Static contraction (n = 17, +344 ± 34 g developed tension) significantly (P < 0.05) increased MAP (+14 ± 3 mmHg), HR (+6 ± 1 beats min^–1) and RSNA (n = 11, +19 ± 5%) and significantly decreased renal cortical vascular conductance (RCVC, n = 11, –11 ± 2%). Passive stretch (n = 20, +378 ± 11 g) also significantly increased MAP (+11 ± 2 mmHg), HR (+7 ± 2 beats min^–1) and RSNA (n = 15, +14 ± 4%) and significantly decreased RCVC (n = 11, –12 ± 3%). RCBF showed no significant changes during static contraction or passive stretch. Renal denervation abolished the decrease in RCVC during contraction (n = 12) or stretch (n = 13). These data indicate that both the exercise pressor reflex and its mechanically sensitive component, the muscle mechanoreflex, induced renal cortical vasoconstriction through sympathetic activation in rats.

(Received 27 July 2005; accepted after revision 4 October 2005; first published online 6 October 2005)
Corresponding author N. Hayashi: Institute of Health Science, Kyushu University, 6-1 Kasuga-Kouen, Kasuga, Fukuoka, 816-8580, Japan. Email: naohayashi{at}ihs.kyushu-u.ac.jp