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Keywords: bradycardia
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Journal Articles
J Exp Biol (2023) 226 (18): jeb246227.
Published: 26 September 2023
... to a stepwise decrease in water oxygen level (100% to 30% air saturation) to determine the oxygen level at which bradycardia occurred. Resting f H was much lower in free-swimming fish than in those in respirometers (∼49 versus 69 beats min −1 ) and this was reflected in their scope for f H (∼104 versus 71 beats...
Includes: Supplementary data
Journal Articles
J Exp Biol (2020) 223 (17): jeb227736.
Published: 11 September 2020
...-conserving mechanisms that support diving are underdeveloped at birth in pinnipeds and cetaceans. This Review explores how underdeveloped physiology makes immature marine mammals vulnerable to disturbance. Acidosis Blood Bradycardia Cetacean Dive response Heart rate Hypercarbia Hypoxia...
Journal Articles
J Exp Biol (2019) 222 (19): jeb208637.
Published: 2 October 2019
...Siri L. Elmegaard; Birgitte I. McDonald; Peter T. Madsen ABSTRACT Pronounced dive responses through peripheral vasoconstriction and bradycardia enable prolonged apnoea in marine mammals. For most vertebrates, the dive response is initiated upon face immersion, but little is known about the physical...
Includes: Supplementary data
Journal Articles
J Exp Biol (2018) 221 (13): jeb176545.
Published: 9 July 2018
... of these factors on diving heart rate are poorly understood because of the difficulty of parsing their relative contributions in diving pinnipeds. Here, we examined the effects of apnea and external sensory inputs as autonomic drivers of bradycardia. Specifically, we hypothesized that (1) water stimulation...
Journal Articles
J Exp Biol (2018) 221 (12): jeb182972.
Published: 22 June 2018
..., this cannot be done without a certain degree of bradycardia to compensate for the ensuing increase in peripheral vascular resistance, and that is what is observed in most voluntary dives (e.g. Kooyman and Campbell, 1972 ; Hill et al., 1987 ). Thus, without knowing how the animal is managing its muscle...
Journal Articles
J Exp Biol (2018) 221 (1): jeb168740.
Published: 9 January 2018
... of bradycardia would be influenced by dive duration and activity, i.e. the dive f H response would be exercise modulated. In all dives, f H decreased compared with surface rates by at least 50% (mean maximum surface f H =173 beats min −1 , mean minimum dive f H =50 beats min −1 ); however, dive f H...
Includes: Supplementary data
Journal Articles
J Exp Biol (2017) 220 (19): 3556–3564.
Published: 1 October 2017
... depression at elevated temperatures. Here, we investigated how water temperature (both acute and chronic exposures) affected the physiology of juvenile estuarine crocodiles ( Crocodylus porosus ) performing predator avoidance dives (i.e. fright-dives). Diving oxygen consumption, ‘fright’ bradycardia...
Includes: Supplementary data
Journal Articles
J Exp Biol (2017) 220 (3): 445–454.
Published: 1 February 2017
...–contraction coupling genes were studied in fish acclimatised to normoxia in summer (+18°C) or winter (+2°C), and in winter fish after 1, 3 and 6 weeks of anoxia. Anoxia induced a sustained bradycardia from a heart rate of 10.3±0.77 beats min −1 to 4.1±0.29 beats min −1 ( P <0.05) after 5 weeks, and heart...
Journal Articles
Journal Articles
J Exp Biol (2012) 215 (16): 2735–2741.
Published: 15 August 2012
...Shawn R. Noren; Traci Kendall; Veronica Cuccurullo; Terrie M. Williams SUMMARY A hallmark of the dive response, bradycardia, promotes the conservation of onboard oxygen stores and enables marine mammals to submerge for prolonged periods. A paradox exists when marine mammals are foraging underwater...
Journal Articles
J Exp Biol (2005) 208 (5): 821–829.
Published: 1 March 2005
... caused significant bradycardia (53.0±3.1). Conversely, pre-branchial occlusion caused a significant tachycardia(69.1±1.7). Prazosin treatment attenuated the bradycardia(57.8±2.9) but not the tachycardia (68.8±2.3). Atropine treatment completely abolished both responses( Fig. 2A ). Fig. 2. Heart...
Journal Articles
Journal Articles
J Exp Biol (2004) 207 (22): 3891–3898.
Published: 15 October 2004
...-mail: schreejf@potsdam.edu ) * Present address: Center for Sleep Research, UCLA/VA-GLAHS, Neurobiology Research 151-A3, 16111 Plummer Street, North Hills, CA 91343, USA 29 7 2004 © The Company of Biologists Limited 2004 2004 apnoea eupnoea respiration heart rate bradycardia sleep...
Journal Articles
Journal Articles
J Exp Biol (2002) 205 (23): 3757–3765.
Published: 1 December 2002
...Nicole M. Elliott; Russel D. Andrews; David R. Jones SUMMARY While diving, harbour seals ( Phoca vitulina ) manage their oxygen stores through cardiovascular adjustments, including bradycardia, a concurrent reduction in cardiac output, and peripheral vasoconstriction. At the surface,post-dive...
Journal Articles
Journal Articles
J Exp Biol (2001) 204 (8): 1519–1527.
Published: 15 April 2001
... the hypercarbia-induced ventilatory responses and virtually eliminated all CO 2 -elicited cardiovascular adjustments. Although the atropinized dogfish displayed a hypercarbic bradycardia, the magnitude of the response was significantly attenuated (36±6 % decrease in f H in controls versus 9±2 % decrease...
Journal Articles
J Exp Biol (1998) 201 (4): 549–558.
Published: 15 February 1998
... Limited 1998 voluntary diving cerebral blood flow rCBF bradycardia cardiac output rat The ability of mammals to dive under water and extend underwater dive duration is dependent upon the utilization of internal oxygen stores. Maximal oxygen utilization is achieved by a cardiovascular...
Journal Articles
J Exp Biol (1997) 200 (15): 2083–2095.
Published: 1 August 1997
... to Año Nuevo. Heart rates during apnoea and eupnoea were recorded from four of the seals after they hauled out on the beach. Diving patterns were very similar to those of naturally migrating juveniles. The heart rate response to apnoea at sea and on land was a prompt bradycardia, but only at sea...
Journal Articles