title: Introducing a novel mechanism to control heart rate in the ancestral Pacific hagfish.
abstract: Although neural modulation of heart rate is well established among chordate animals, the Pacific hagfish (Eptatretus stoutii) lacks any cardiac innervation, yet it can increase its heart rate from the steady, depressed heart rate seen in prolonged anoxia to almost double its normal normoxic heart rate, an almost fourfold overall change during the 1-h recovery from anoxia. The present study sought mechanistic explanations for these regulatory changes in heart rate. We provide evidence for a bicarbonate-activated, soluble adenylyl cyclase (sAC)-dependent mechanism to control heart rate, a mechanism never previously implicated in chordate cardiac control.
authors: Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia, Canada V6T 1Z4 cwilson@larrea.cl.
authors: Christopher M
authors: 0000-0002-1471-857X
authors: CM
authors: Wilson
authors: Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
authors: Jinae N
authors: JN
authors: Roa
authors: Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia, Canada V6T 1Z4.
authors: Georgina K
authors: GK
authors: Cox
authors: Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.
authors: Martin
authors: M
authors: Tresguerres
authors: Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia, Canada V6T 1Z4.|Faculty of Land and Food Systems, University of British Columbia, 2357 Main Mall, Vancouver, British Columbia, Canada V6T 1Z4.
authors: Anthony P
authors: AP
authors: Farrell
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D002462:Cell Membrane / Q000201:enzymology; D000242:Cyclic AMP / Q000378:metabolism; D005260:Female; D006196:Hagfishes / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology*; D000860:Hypoxia / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D009206:Myocardium / Q000201:enzymology; D011943:Receptors, Adrenergic, beta / Q000378:metabolism; D027982:Sodium-Bicarbonate Symporters / Q000378:metabolism; D012995:Solubility
chemical_list: D011943:Receptors, Adrenergic, beta; D027982:Sodium-Bicarbonate Symporters; D000242:Cyclic AMP; D000262:Adenylyl Cyclases
keywords: 
  Cardiac evolution; Anoxia tolerance; Bicarbonate ions; Heart rate control; Soluble adenylyl cyclase; cAMP production