Electrical activity and mechanical response in the systemic heart and the portal vein heart of Myxine glutinosa

Electrical Excitation of the Heart in a Basal Vertebrate, the European River Lamprey (Lampetra fluviatilis)

“…However, the RMP values measured in this study for L. fluviatilis are much more negative than previously reported for hagfish (Myxine glutinosa, Myxine circifrons, Eptatretus stoutii, and Eptatretus deani) hearts (230 to 250 mV at 207-237C; Jensen 1965;Arlock 1975). RMP of the cell is measured relative to the external solution and is largely dependent on K 1 ion concentration of the bathing solution (assuming that RMP is determined by K 1 currents).…”

Electrical Excitation of the Heart in a Basal Vertebrate, the European River Lamprey (Lampetra fluviatilis)

“…However, the RMP values measured in this study for L. fluviatilis are much more negative than previously reported for hagfish (Myxine glutinosa, Myxine circifrons, Eptatretus stoutii, and Eptatretus deani) hearts (230 to 250 mV at 207-237C; Jensen 1965;Arlock 1975). RMP of the cell is measured relative to the external solution and is largely dependent on K 1 ion concentration of the bathing solution (assuming that RMP is determined by K 1 currents).…”

Morphological analysis of the hagfish heart. II. The venous pole and the pericardium

“…However, it was observed only in E. cirrhatus and only when the electrode was placed in the central region of the sinus venosus (Davie et al, 1987). Similar studies in M. glutinosa did not report on sinus venosus electrical activity (Arlock, 1975;Satchell, 1986). Nonetheless, electrical activity in the hagfish heart is quite unusual because excised myocardial fragments exhibit a high degree of automatism and many myocardiocytes throughout the atrium and ventricle show pacemaking characteristics (Jensen, 1965;Arlock, 1975).…”

“…Similar studies in M. glutinosa did not report on sinus venosus electrical activity (Arlock, 1975;Satchell, 1986). Nonetheless, electrical activity in the hagfish heart is quite unusual because excised myocardial fragments exhibit a high degree of automatism and many myocardiocytes throughout the atrium and ventricle show pacemaking characteristics (Jensen, 1965;Arlock, 1975). Myocardiocytes exhibit low resting membrane potentials (Jensen, 1965) and are rich in hyperpolarizationactivated cyclic nucleotide-gated (HCN) ionic channels (Wilson and Farrel, 2013).…”

Cardiac Function in the Hagfish, Myxine (Myxinoidea:Cyclostomata)

“…The ECG Radner et al (1972) and Arlock (1975) noted that the ECG of Myxine lacks the V wave signalling sinus contraction, such as Oets (1950) described in the eel Anguilla vulgaris. Ten Cate and Punt (1960) noted a similar absence in the lamprey Petromyzon.…”

“…Total ventricular systole lasted for 1.30 f 0.19 s ( n = 7). Arlock (1975) reports this event as lasting 0.92 s at 20°C.…”

Electrical Excitation of the Heart in a Basal Vertebrate, the European River Lamprey (Lampetra fluviatilis)

“…However, the RMP values measured in this study for L. fluviatilis are much more negative than previously reported for hagfish (Myxine glutinosa, Myxine circifrons, Eptatretus stoutii, and Eptatretus deani) hearts (230 to 250 mV at 207-237C; Jensen 1965;Arlock 1975). RMP of the cell is measured relative to the external solution and is largely dependent on K 1 ion concentration of the bathing solution (assuming that RMP is determined by K 1 currents).…”

Morphological analysis of the hagfish heart. II. The venous pole and the pericardium

“…However, it was observed only in E. cirrhatus and only when the electrode was placed in the central region of the sinus venosus (Davie et al, 1987). Similar studies in M. glutinosa did not report on sinus venosus electrical activity (Arlock, 1975;Satchell, 1986). Nonetheless, electrical activity in the hagfish heart is quite unusual because excised myocardial fragments exhibit a high degree of automatism and many myocardiocytes throughout the atrium and ventricle show pacemaking characteristics (Jensen, 1965;Arlock, 1975).…”

“…Similar studies in M. glutinosa did not report on sinus venosus electrical activity (Arlock, 1975;Satchell, 1986). Nonetheless, electrical activity in the hagfish heart is quite unusual because excised myocardial fragments exhibit a high degree of automatism and many myocardiocytes throughout the atrium and ventricle show pacemaking characteristics (Jensen, 1965;Arlock, 1975). Myocardiocytes exhibit low resting membrane potentials (Jensen, 1965) and are rich in hyperpolarizationactivated cyclic nucleotide-gated (HCN) ionic channels (Wilson and Farrel, 2013).…”

Cardiac Function in the Hagfish, Myxine (Myxinoidea:Cyclostomata)

“…The ECG Radner et al (1972) and Arlock (1975) noted that the ECG of Myxine lacks the V wave signalling sinus contraction, such as Oets (1950) described in the eel Anguilla vulgaris. Ten Cate and Punt (1960) noted a similar absence in the lamprey Petromyzon.…”

“…Total ventricular systole lasted for 1.30 f 0.19 s ( n = 7). Arlock (1975) reports this event as lasting 0.92 s at 20°C.…”

Electrical Excitation of the Heart in a Basal Vertebrate, the European River Lamprey (Lampetra fluviatilis)

“…However, the RMP values measured in this study for L. fluviatilis are much more negative than previously reported for hagfish (Myxine glutinosa, Myxine circifrons, Eptatretus stoutii, and Eptatretus deani) hearts (230 to 250 mV at 207-237C; Jensen 1965;Arlock 1975). RMP of the cell is measured relative to the external solution and is largely dependent on K 1 ion concentration of the bathing solution (assuming that RMP is determined by K 1 currents).…”

Morphological analysis of the hagfish heart. II. The venous pole and the pericardium

“…However, it was observed only in E. cirrhatus and only when the electrode was placed in the central region of the sinus venosus (Davie et al, 1987). Similar studies in M. glutinosa did not report on sinus venosus electrical activity (Arlock, 1975;Satchell, 1986). Nonetheless, electrical activity in the hagfish heart is quite unusual because excised myocardial fragments exhibit a high degree of automatism and many myocardiocytes throughout the atrium and ventricle show pacemaking characteristics (Jensen, 1965;Arlock, 1975).…”

“…Similar studies in M. glutinosa did not report on sinus venosus electrical activity (Arlock, 1975;Satchell, 1986). Nonetheless, electrical activity in the hagfish heart is quite unusual because excised myocardial fragments exhibit a high degree of automatism and many myocardiocytes throughout the atrium and ventricle show pacemaking characteristics (Jensen, 1965;Arlock, 1975). Myocardiocytes exhibit low resting membrane potentials (Jensen, 1965) and are rich in hyperpolarizationactivated cyclic nucleotide-gated (HCN) ionic channels (Wilson and Farrel, 2013).…”

Cardiac Function in the Hagfish, Myxine (Myxinoidea:Cyclostomata)

“…The ECG Radner et al (1972) and Arlock (1975) noted that the ECG of Myxine lacks the V wave signalling sinus contraction, such as Oets (1950) described in the eel Anguilla vulgaris. Ten Cate and Punt (1960) noted a similar absence in the lamprey Petromyzon.…”

“…Total ventricular systole lasted for 1.30 f 0.19 s ( n = 7). Arlock (1975) reports this event as lasting 0.92 s at 20°C.…”