• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Elephant Seal; harbor seal; Phoca vitulina; Callorhinus ursinus; Northern fur seal
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.537.162; http://facultyfp.salisbury.edu/eewilliams/documents/Can J Zool 2001.pdf

Hydrostatic-pressure and temperature effects on the molecular order of erythrocyte membranes from deep-, shallow-, and non-diving mammals E.E. Williams, B.S. Stewart, C.A. Beuchat, G.N. Somero, and J.R. Hazel Abstract: Little is known about the cellular mechanisms involved in the tolerance of deep-diving marine mammals to hydrostatic pressures that cause serious pathologies when experienced by other mammals. We compared fatty-acid com-position, cholesterol content, and the effects of pressure on the molecular order of erythrocyte membranes from deep-, shallow-, and non-diving mammals to determine how these properties may be related to diving performance. Erythrocytes were collected from two deep-diving phocid pinnipeds (northern elephant seal (Mirounga angustirostris) and harbor seal (Phoca vitulina)), a relatively shallow-diving otariid pinniped (northern fur seal (Callorhinus ursinus)), and several nondiving terrestrial mammals (dog (Canis familiaris), horse (Equus caballus), and cow (Bos taurus)). Fatty-acid com-position clearly distinguished the phocids from the other species. The monoene content of erythrocyte membranes was substantially lower (3 vs. » 20%), whereas the lipid unsaturation indices, the ratio of a- to g-linolenic acids, and the proportions of long-chain polyunsaturated fatty acids were substantially higher in the phocids. The cell-membrane cholesterol content was also significantly lower in erythrocytes from the deep-diving phocids (cholesterol:phospholipid