Pressure profile and morphology of the arteries along the giraffe limb
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Standard
Pressure profile and morphology of the arteries along the giraffe limb. / Østergaard, Kristine Hovkjær; Bertelsen, Mads Frost; Brøndum, Emil Toft; Aalkjær, Christian; Hasenkam, Michael; Smerup, Morten Holdgaard; Nielsen, Tobias Wang; Nyengaard, Jens Randel; Baandrup, Ulrik.
I: Journal of Comparative Physiology B: Biochemical, Systems, and Environmental Physiology, Bind 181, Nr. 5, 2011, s. 691-698.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
Harvard
APA
Vancouver
Author
Bibtex
}
RIS
TY - JOUR
T1 - Pressure profile and morphology of the arteries along the giraffe limb
AU - Østergaard, Kristine Hovkjær
AU - Bertelsen, Mads Frost
AU - Brøndum, Emil Toft
AU - Aalkjær, Christian
AU - Hasenkam, Michael
AU - Smerup, Morten Holdgaard
AU - Nielsen, Tobias Wang
AU - Nyengaard, Jens Randel
AU - Baandrup, Ulrik
PY - 2011
Y1 - 2011
N2 - Giraffes are the tallest animals on earth and the effects of gravity on their cardiovascular system have puzzled physiologists for centuries. The authors measured arterial and venous pressure in the foreleg of anesthetized giraffes, suspended in upright standing position, and determined the ratio between tunica media and lumen areas along the length of the femoral/tibial arteries in the hindleg. Volume fraction of elastin, density of vasa vasorum and innervations was estimated by stereology. Immunohistological staining with S100 was used to examine the innervation. The pressure increase in the artery and vein along the foreleg was not significantly different from what was expected on basis of gravity. The area of the arterial lumen in the hindleg decreased towards the hoof from 11.2 ± 4.2 to 0.6 ± 0.5 mm(2) (n = 10, P = 0.001), but most of this narrowing occurred within 2-4 cm immediately below the knee. This abrupt narrowing was associated with a marked increase in media to lumen area ratio (from 1.2 ± 0.5 to 7.8 ± 2.5; P = 0.001), and a decrease in mean volume fraction of elastin from 38 ± 6% proximal to the narrowing to 5.8 ± 1.1% distally (P = 0.001). The narrowing had a six-fold higher innervation density than the immediate distal and proximal regions. The sudden narrowing was also observed in the hind legs of neonates, indicating that it does not develop as an adaptation to the high transmural pressure in the standing giraffe. More likely it represents a preadaptation to the high pressures experienced by adult giraffes.
AB - Giraffes are the tallest animals on earth and the effects of gravity on their cardiovascular system have puzzled physiologists for centuries. The authors measured arterial and venous pressure in the foreleg of anesthetized giraffes, suspended in upright standing position, and determined the ratio between tunica media and lumen areas along the length of the femoral/tibial arteries in the hindleg. Volume fraction of elastin, density of vasa vasorum and innervations was estimated by stereology. Immunohistological staining with S100 was used to examine the innervation. The pressure increase in the artery and vein along the foreleg was not significantly different from what was expected on basis of gravity. The area of the arterial lumen in the hindleg decreased towards the hoof from 11.2 ± 4.2 to 0.6 ± 0.5 mm(2) (n = 10, P = 0.001), but most of this narrowing occurred within 2-4 cm immediately below the knee. This abrupt narrowing was associated with a marked increase in media to lumen area ratio (from 1.2 ± 0.5 to 7.8 ± 2.5; P = 0.001), and a decrease in mean volume fraction of elastin from 38 ± 6% proximal to the narrowing to 5.8 ± 1.1% distally (P = 0.001). The narrowing had a six-fold higher innervation density than the immediate distal and proximal regions. The sudden narrowing was also observed in the hind legs of neonates, indicating that it does not develop as an adaptation to the high transmural pressure in the standing giraffe. More likely it represents a preadaptation to the high pressures experienced by adult giraffes.
KW - Animals
KW - Arteries
KW - Blood Pressure
KW - Elastin
KW - Female
KW - Femoral Artery
KW - Forelimb
KW - Hindlimb
KW - Male
KW - Ruminants
KW - Tibial Arteries
KW - Tunica Media
KW - Giraffa camelopardalis
KW - Histology
KW - Femoral/tibial artery
KW - Innervation
KW - Pressure
U2 - 10.1007/s00360-010-0545-z
DO - 10.1007/s00360-010-0545-z
M3 - Journal article
C2 - 21207038
VL - 181
SP - 691
EP - 698
JO - Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology
JF - Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology
SN - 0174-1578
IS - 5
ER -
ID: 37607676