Circadian rhythms in blood pressure in free-ranging three-toed sloths (Bradypus variegatus)
Blood pressure (BP) profiles were monitored in nine free-ranging sloths (Bradypus variegatus) by coupling one common carotid artery to a BP telemetry transmitter. Animals moved freely in an isolated and temperature-controlled room (24ºC) with 12/12-h artificial light-dark cycles and behaviors were o...
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| Format: | Article |
| Language: | English |
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Associação Brasileira de Divulgação Científica
2003-01-01
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| Series: | Brazilian Journal of Medical and Biological Research |
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| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003000200016 |
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| author | Duarte D.P.F. Silva V.L. Jaguaribe A.M. Gilmore D.P. Da Costa C.P. |
| author_facet | Duarte D.P.F. Silva V.L. Jaguaribe A.M. Gilmore D.P. Da Costa C.P. |
| author_sort | Duarte D.P.F. |
| collection | DOAJ |
| description | Blood pressure (BP) profiles were monitored in nine free-ranging sloths (Bradypus variegatus) by coupling one common carotid artery to a BP telemetry transmitter. Animals moved freely in an isolated and temperature-controlled room (24ºC) with 12/12-h artificial light-dark cycles and behaviors were observed during resting, eating and moving. Systolic (SBP) and diastolic (DBP) blood pressures were sampled for 1 min every 15 min for 24 h. BP rhythm over 24 h was analyzed by the cosinor method and the mesor, amplitude, acrophase and percent rhythm were calculated. A total of 764 measurements were made in the light cycle and 721 in the dark cycle. Twenty-four-hour values (mean ± SD) were obtained for SBP (121 ± 22 mmHg), DBP (86 ± 17 mmHg), mean BP (MBP, 98 ± 18 mmHg) and heart rate (73 ± 16 bpm). The SBP, DBP and MBP were significantly higher (unpaired Student t-test) during the light period (125 ± 21, 88 ± 15 and 100 ± 17 mmHg, respectively) than during the dark period (120 ± 21, 85 ± 17 and 97 ± 17 mmHg, respectively) and the acrophase occurred between 16:00 and 17:45 h. This circadian variation is similar to that observed in cats, dogs and marmosets. The BP decreased during "behavioral sleep" (MBP down from 110 ± 19 to 90 ± 19 mmHg at 21:00 to 8:00 h). Both feeding and moving induced an increase in MBP (96 ± 17 to 119 ± 17 mmHg at 17:00 h and 97 ± 19 to 105 ± 12 mmHg at 15:00 h, respectively). The results show that conscious sloths present biphasic circadian fluctuations in BP levels, which are higher during the light period and are mainly synchronized with feeding. |
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| institution | Directory Open Access Journal |
| issn | 0100-879X 0034-7310 |
| language | English |
| last_indexed | 2024-12-12T16:25:05Z |
| publishDate | 2003-01-01 |
| publisher | Associação Brasileira de Divulgação Científica |
| record_format | Article |
| series | Brazilian Journal of Medical and Biological Research |
| spelling | doaj.art-3d9289cfd8bd4d569b4299c20f4e34062022-12-22T00:18:53ZengAssociação Brasileira de Divulgação CientíficaBrazilian Journal of Medical and Biological Research0100-879X0034-73102003-01-01362273278Circadian rhythms in blood pressure in free-ranging three-toed sloths (Bradypus variegatus)Duarte D.P.F.Silva V.L.Jaguaribe A.M.Gilmore D.P.Da Costa C.P.Blood pressure (BP) profiles were monitored in nine free-ranging sloths (Bradypus variegatus) by coupling one common carotid artery to a BP telemetry transmitter. Animals moved freely in an isolated and temperature-controlled room (24ºC) with 12/12-h artificial light-dark cycles and behaviors were observed during resting, eating and moving. Systolic (SBP) and diastolic (DBP) blood pressures were sampled for 1 min every 15 min for 24 h. BP rhythm over 24 h was analyzed by the cosinor method and the mesor, amplitude, acrophase and percent rhythm were calculated. A total of 764 measurements were made in the light cycle and 721 in the dark cycle. Twenty-four-hour values (mean ± SD) were obtained for SBP (121 ± 22 mmHg), DBP (86 ± 17 mmHg), mean BP (MBP, 98 ± 18 mmHg) and heart rate (73 ± 16 bpm). The SBP, DBP and MBP were significantly higher (unpaired Student t-test) during the light period (125 ± 21, 88 ± 15 and 100 ± 17 mmHg, respectively) than during the dark period (120 ± 21, 85 ± 17 and 97 ± 17 mmHg, respectively) and the acrophase occurred between 16:00 and 17:45 h. This circadian variation is similar to that observed in cats, dogs and marmosets. The BP decreased during "behavioral sleep" (MBP down from 110 ± 19 to 90 ± 19 mmHg at 21:00 to 8:00 h). Both feeding and moving induced an increase in MBP (96 ± 17 to 119 ± 17 mmHg at 17:00 h and 97 ± 19 to 105 ± 12 mmHg at 15:00 h, respectively). The results show that conscious sloths present biphasic circadian fluctuations in BP levels, which are higher during the light period and are mainly synchronized with feeding.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003000200016SlothsBradypusCircadian rhythmBlood pressure |
| spellingShingle | Duarte D.P.F. Silva V.L. Jaguaribe A.M. Gilmore D.P. Da Costa C.P. Circadian rhythms in blood pressure in free-ranging three-toed sloths (Bradypus variegatus) Brazilian Journal of Medical and Biological Research Sloths Bradypus Circadian rhythm Blood pressure |
| title | Circadian rhythms in blood pressure in free-ranging three-toed sloths (Bradypus variegatus) |
| title_full | Circadian rhythms in blood pressure in free-ranging three-toed sloths (Bradypus variegatus) |
| title_fullStr | Circadian rhythms in blood pressure in free-ranging three-toed sloths (Bradypus variegatus) |
| title_full_unstemmed | Circadian rhythms in blood pressure in free-ranging three-toed sloths (Bradypus variegatus) |
| title_short | Circadian rhythms in blood pressure in free-ranging three-toed sloths (Bradypus variegatus) |
| title_sort | circadian rhythms in blood pressure in free ranging three toed sloths bradypus variegatus |
| topic | Sloths Bradypus Circadian rhythm Blood pressure |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2003000200016 |
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