title: [The dependence of the rate of heart contractions in the long-tailed Yakutsk suslik Citellus undulatus on environmental temperature].
abstract: Decrease of ambient temperature (Ta) leads to the increase of the heart rate (HR) in active ground squirrels C. undulatus by 5.3/min/1 degree C in summer and by 3.8/min/1 degree C in winter. In a hibernation state, the dependence of the HR on Ta was in a good agreement with equation HT = 2.53.exp.(0.1.Ta). On entering into hibernation and on arousal, the HR change outruns the corresponding body temperature (Tb) change by 1.5-2 hours. A maximum HR level (up to 400/min and more) was registered on arousal when Tb reached 17-20 degrees C. A minimal HR level (4-5/min) was observed during hibernation at Ta 2-5 degrees C. The maximum Ta, at witch C. undulatus was hibernating, reached 23-24 degrees C, the HR being 23-25/min.
authors.forename: D A
authors.initials: DA
authors.lastname: Ignat'ev
authors.forename: G S
authors.initials: GS
authors.lastname: Sukhova
authors.forename: V P
authors.initials: VP
authors.lastname: Sukhov
mesh_terms: D000818:Animals; D006339:Heart Rate / Q000502:physiology*; D006605:Hibernation / Q000502:physiology; D012589:Sciuridae / Q000502:physiology*; D012800:Siberia; D013686:Telemetry; D013696:Temperature; D013821:Thermometers; D013997:Time Factors; D014851:Wakefulness / Q000502:physiology
vernacular_title: Zavisimost' chastoty serdechnykh sokrashcheniĭ iakutskogo dlinnokhvostogo suslika Citellus undulatus ot temperatury vneshneĭ sredy.