Diurnal, seasonal, and sex patterns of heart rate in grip‐restrained African giant rats (Cricetomys gambianus, Waterhouse)

• Published in: Physiological reports Vol. 3; no. 10; pp. e12581 - n/a
• Main Authors: Dzenda, Tavershima, Ayo, Joseph O., Sinkalu, Victor O., Yaqub, Lukuman S.
• Format: Journal Article
• Language: English
• Published: United States John Wiley & Sons, Inc 01-10-2015; John Wiley & Sons, Ltd
• Subjects: Animals; Body temperature; Cricetomys gambianus; Diurnal; Diurnal rhythm; Feeds; Females; Gender differences; giant rats; Heart rate; Influence; Original Research; Physiology; Savannah; season; Seasons; Sex; Sexes; Values; Africa; season; Diurnal rhythm; heart rate; Savannah; giant rats; sex
• ISSN: 2051-817X; 2051-817X
• DOI: 10.14814/phy2.12581

This study was carried out to determine heart rate (HR) values, including diurnal, seasonal, and sex patterns, in the African giant rat (Cricetomys gambianus, Waterhouse). HR was measured using stethoscope in grip‐restrained African giant rats of either sex (103 bucks and 98 does), live‐trapped from a tropical Savannah, and caged individually in the laboratory during the harmattan (cold‐dry), hot‐dry, and rainy seasons over a 3‐year period. The HR fluctuated between 90 and 210 beats per minute (bpm) throughout the study period. Diurnal changes in HR (mean ± SEM) during the hot‐dry and rainy seasons were nonsignificant (P > 0.05), but the morning and afternoon values differed (P < 0.01) during the cold‐dry season. The HR varied (P < 0.05) among seasons, with peak, nadir, and moderate values recorded during the cold‐dry (165.8 ± 0.51 bpm), hot‐dry (153.1 ± 0.74 bpm), and rainy (163.4 ± 0.70 bpm) seasons, respectively. Mean HR of bucks was lower than that of does during the cold‐dry (P < 0.0001) and hot‐dry (P < 0.01) seasons, but sex difference during the rainy season was insignificant (P > 0.05). Overall, mean HR was lower (P < 0.0001) in bucks (158.8 ± 0.53 bpm) than in does (164.8 ± 0.53 bpm). In conclusion, values of HR in African giant rats are shown for the first time. Season, sex, and daytime influenced the HR, and should be considered during clinical evaluations of the rats.
Heart rate was measured in grip‐restrained African giant rats (Cricetomys gambianus) over a 3‐year period to determine baseline diurnal, seasonal, and sex patterns. The diurnal and seasonal rhythms of the heart rate were modest and robust, respectively, with values significantly higher in doe than buck rats. Therefore, diurnal, seasonal, and sex influences should be considered during clinical evaluations of the giant rats.