3301 The Journal of Experimental Biology 210, 3301-3310 Published by The Company of Biologists 2007 doi:10.1242/jeb.006106 Ventilatory and cardiovascular actions of centrally administered trout tachykinins in the unanesthetized trout Jean-Claude Le Mével1,*, Frédéric Lancien1, Nagi Mimassi1 and J. Michael Conlon2 1Laboratoire de Traitement de l’Information Médicale, INSERM U650, and Laboratoire de Neurophysiologie, Faculté de Médecine et des Sciences de la Santé, Université de Bretagne Occidentale, 22 avenue Camille Desmoulins, CS 93837, 29238 Brest Cedex 3, France and 2Department of Biochemistry, Faculty of Medicine and Health Sciences, United Arab Emirates University, 17666 Al Ain, United Arab Emirates *Author for correspondence (e-mail:
[email protected]) Accepted 17 July 2007 Summary The brains of teleost fish contain members of the in VTOT but only at the highest dose (250·pmol). NKA was tachykinin family that are the products of orthologous without action on fV but significantly decreased VAMP at genes expressed in mammalian nervous tissues, but little is only the highest dose tested. In this case also, the net effect known regarding the physiological effects of these peptides of NKA was to reduce VTOT. When injected centrally, none in their species of origin. The present study compares the of the three peptides, at any dose tested, produced changes central actions of trout neuropeptide gamma (NP␥), in heart rate or mean dorsal aortic blood pressure (PDA). substance P (SP) and neurokinin A (NKA) (5–250·pmol) Intra-arterial injection of the three tachykinins (250·pmol) on ventilatory and cardiovascular parameters in the produced a significant (P<0.05) increase in PDA, but only unanesthetized rainbow trout Oncorhynchus mykiss.