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Low blood volume in the giraffe (Giraffa camelopardalis)
Author(s) -
Damkjær Mads,
Bertelsen Mads,
Grøndahl Carsten,
Hasenkam Michael,
Wang Tobias,
Brøndum Emil,
Candy Geoffrey,
Bie Peter
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.1027.17
Subject(s) - hematocrit , blood volume , bolus (digestion) , hemodynamics , blood pressure , body weight , chemistry , cardiac output , hemoglobin , zoology , volume (thermodynamics) , anesthesia , anatomy , medicine , biology , physics , quantum mechanics
The giraffe exhibits extraordinary hemodynamics including a high blood pressure at heart level. As part of a larger study, we hypothesized that its blood volume is 75–80 ml/kg body weight (b.wt.) as in other mammals. Six male giraffes were anesthetized and intubated. At induction, a bolus of Evans' blue (~0.5 mg/kg b.wt.) was given i.v. Blood samples were obtained approx. every 10 min for at least 75 min. Plasma was separated immediately and the theoretical dye concentration at time of injection determined by extrapolation of the spectrophotometric data. Plasma volume was 32.3 ±3.6 ml/kg b.wt. (mean ± SE, n=6), and blood volume was 56.0 ±4.9 ml/kg b.wt. based on hematocrit values of 42.7 ±1.5 %. Cardiac output (CO, determined by the rebreathing technique (Innocor®)) averaged 33.8 ±1.7 ml/(min·kg b.wt.)(n=5). The results suggest that giraffes are peculiar hemodynamically also because of low blood volume and low cardiac output. The low blood volume may be related to low compliance of the vascular system, and the low CO may be an element in explaining why relative heart mass in the giraffe is similar to that of other mammals. Supported by the Danish Cardiovascular Giraffe Research Programme (DaGiR).