TY - JOUR
T1 - Central pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) decrease the baroreflex sensitivity in trout
AU - Lancien, Frédéric
AU - Mimassi, Nagi
AU - Conlon, J. Michael
AU - Mével, Jean Claude Le
PY - 2011/4/1
Y1 - 2011/4/1
N2 - Although PACAP and VIP exert diverse actions on heart and blood vessels along the vertebrate phylum, no information is currently available concerning the potential role of these peptides on the regulation of the baroreflex response, a major mechanism for blood pressure homeostasis. Consequently, the goal of this study was to examine in our experimental model, the unanesthetized rainbow trout Oncorhynchus mykiss, whether PACAP and VIP are involved in the regulation of the cardiac baroreflex sensitivity (BRS). Cross-spectral analysis techniques using a fast Fourier transform algorithm were employed to calculate the coherence, phase and gain of the transfer function between spontaneous fluctuations of systolic arterial blood pressure and R-R intervals of the electrocardiogram. The BRS was estimated as the mean of the gain of the transfer function when the coherence between the two signals was high and the phase negative. Compared with vehicle, intracerebroventricular (ICV) injections of trout PACAP-27 and trout VIP (25-100. pmol) dose-dependently reduced the cardiac BRS to the same extent with a threshold dose of 50. pmol for a significant effect. When injected intra-arterially at the same doses as for ICV injections, only the highest dose of VIP (100. pmol) significantly attenuated the BRS. These results suggest that the endogenous peptides PACAP and VIP might be implicated in the central control of cardiac baroreflex functions in trout.
AB - Although PACAP and VIP exert diverse actions on heart and blood vessels along the vertebrate phylum, no information is currently available concerning the potential role of these peptides on the regulation of the baroreflex response, a major mechanism for blood pressure homeostasis. Consequently, the goal of this study was to examine in our experimental model, the unanesthetized rainbow trout Oncorhynchus mykiss, whether PACAP and VIP are involved in the regulation of the cardiac baroreflex sensitivity (BRS). Cross-spectral analysis techniques using a fast Fourier transform algorithm were employed to calculate the coherence, phase and gain of the transfer function between spontaneous fluctuations of systolic arterial blood pressure and R-R intervals of the electrocardiogram. The BRS was estimated as the mean of the gain of the transfer function when the coherence between the two signals was high and the phase negative. Compared with vehicle, intracerebroventricular (ICV) injections of trout PACAP-27 and trout VIP (25-100. pmol) dose-dependently reduced the cardiac BRS to the same extent with a threshold dose of 50. pmol for a significant effect. When injected intra-arterially at the same doses as for ICV injections, only the highest dose of VIP (100. pmol) significantly attenuated the BRS. These results suggest that the endogenous peptides PACAP and VIP might be implicated in the central control of cardiac baroreflex functions in trout.
KW - Baroreflex
KW - Intra-arterial injection
KW - Intracerebroventricular injection
KW - PACAP
KW - R-R interval and systolic blood pressure variabilities
KW - Teleost
KW - Transfer function analysis
KW - VIP
UR - http://www.scopus.com/inward/record.url?scp=79952466756&partnerID=8YFLogxK
U2 - 10.1016/j.ygcen.2011.02.006
DO - 10.1016/j.ygcen.2011.02.006
M3 - Article
AN - SCOPUS:79952466756
SN - 0016-6480
VL - 171
SP - 245
EP - 251
JO - General and Comparative Endocrinology
JF - General and Comparative Endocrinology
IS - 2
ER -