FN Archimer Export Format PT J TI Cardiac preload and venous return in swimming sea bass (Dicentrarchus labrax L.) BT AF SANDBLOM, Erik FARRELL, Anthony ALTIMIRAS, Jordi AXELSSON, Michael CLAIREAUX, Guy AS 1:1;2:2;3:3;4:1;5:4,5; FF 1:;2:;3:;4:;5:; C1 Univ Gothenburg, Dept Zool, S-40530 Gothenburg, Sweden. Univ British Columbia, Fac Agr Sci, Vancouver, BC V6T 1Z4, Canada. Linkoping Univ, Inst Phys & Measurement Technol, Dept Biol, S-58183 Linkoping, Sweden. IFREMER, CNRS, Ctr Rech Ecosyst Marins & Aquacoles, F-17137 Lhoumeau, France. C2 UNIV GOTHENBURG, SWEDEN UNIV BRITISH COLUMBIA, CANADA UNIV LINKOPING, SWEDEN IFREMER, FRANCE CNRS, FRANCE SI LA ROCHELLE SE PDG-DOP-DCN-AGSAE-CREMA IN WOS Ifremer jusqu'en 2018 copubli-france copubli-europe copubli-int-hors-europe IF 2.712 TC 40 UR https://archimer.ifremer.fr/doc/2005/publication-421.pdf LA English DT Article DE ;Blood pressure;Cardiac rythm;Swimming aquaculture;Sea bass AB Cardiac preload (central venous; pressure, Pcv), mean circulatory filling pressure (MCFP), dorsal aortic blood pressure (P-DA) and relative cardiac output (Q) were measured in sea bass (Dicentrarchus labrax) at rest and while swimming at 1 and 2 BL s(-1). MCFP, an index of venous capacitance and the upstream venous pressure driving the return of venous blood to the heart, was measured as the plateau in Pcv during ventral aortic occlusion. Compared with resting values, swimming at 1 and 2BL s(-1) increased Q (by 15 +/- 1.5 and 38 +/- 6.5%, respectively), Pcv (from 0.11 +/- 0.01 kPa to 0.12 +/- 0.01 and 0.16 +/- 0.02 kPa, respectively), MCFP (from 0.27 +/- 0.02 kPa to 0.31 +/- 0.02 and 0.40 +/- 0.04 kPa, respectively) and the calculated pressure gradient for venous return (Delta Pv, from 0.16 +/- 0.01 kPa to 0.18 +/- 0.02 and 0.24 +/- 0.02 kPa, respectively), but not PDA. In spite of an increased preload, the increase in 0 was exclusively mediated by an increased heart rate (fH, from 80 +/- 4 beats min(-1) to 88 +/- 4 and 103 +/- 3 beats min(-1), respectively), and stroke volume (V-s) remained unchanged. Prazosin treatment (1 mg kg(-1) M-b) abolished pressure and flow changes during swimming at 1 BL s(-1), but not 2 BL s(-1), indicating that other control systems besides an alpha-adrenoceptor control are involved. This study is the first to address the control of venous capacitance in swimming fish. It questions the generality that increased Q during swimming is regulated primarily through V-s and shows that an increased cardiac filling pressure does not necessarily lead to an increased V-s in fish, but may instead compensate for a reduced cardiac filling time. PY 2005 PD MAY SO The Journal of Experimental Biology SN 0022-0949 PU The Company of Biologists VL 208 IS 10 UT 000229874300020 BP 1927 EP 1935 DI 10.1242/jeb.01606 ID 421 ER EF