The annual land-based reproductive and molting behavior of the Northern elephant seal as well as its exceptional diving behavior are widely recognized as an exceptional opportunity for the study of the physiological and biochemical events underlying these unusual abilities in a free-living mammal under natural conditions. Among the more unusual features of this annual 'amphibious' phenomenon is that with the exception of nursing pups all individuals fast entirely for 1-3 months while on land. In addition, while at sea all elephant seals dive continuously for from 3 to 7 months spending more than 90% of the time underwater at depths averaging 400m and occasionally in excess of 1000m. The research conducted over the last 20 years, sponsored by MBRS, other institutes of the HIH, NSF and other agencies, has provided a wealth of basic biological as well as medically relevant data. Of particular importance is an appreciation of some of the mechanisms which allow elephant seals to maintain physiological homeostasis during these natural fasts in stark contrast to the severe pathologies observed in other mammals including humans as a consequence of starvation or early childhood malnutrition or starvation which today reached global, epidemic proportion as well as clinically related conditions such as diabetes, kidney disorders, severe burns, and HPNS High Pressure Nervous Syndrome.

Project Start
Project End
Budget Start
Budget End
Support Year
21
Fiscal Year
1996
Total Cost
Indirect Cost
Patterson-Buckendahl, P; Adams, S H; Morales, R et al. (1994) Skeletal development in newborn and weanling northern elephant seals. Am J Physiol 267:R726-34
Endo, H; Yamaguchi, M; Farnsworth, R et al. (1994) Mouse placental cells secrete immunoreactive growth hormone-releasing factor. Biol Reprod 51:1206-12
Yamaguchi, M; Ogren, L; Barnard, R et al. (1994) Selective inhibition of mouse placental lactogen II secretion by tumour necrosis factor-alpha. J Endocrinol 143:95-105
Yamaguchi, M; Ogren, L; Endo, H et al. (1994) Co-localization of placental lactogen-I, placental lactogen-II, and proliferin in the mouse placenta at midpregnancy. Biol Reprod 51:1188-92
Ferea, T; Contreras, E T; Oung, T et al. (1994) Characterization of the cit-1 gene from Neurospora crassa encoding the mitochondrial form of citrate synthase. Mol Gen Genet 242:105-10
Yamaguchi, M; Ogren, L; Southard, J N et al. (1993) Interleukin 6 inhibits mouse placental lactogen II but not mouse placental lactogen I secretion in vitro. Proc Natl Acad Sci U S A 90:11905-9
Okamuro, J K; den Boer, B G; Jofuku, K D (1993) Regulation of Arabidopsis flower development. Plant Cell 5:1183-93
Sista, H; Bowman, B (1992) Characterization of the ilv-2 gene from Neurospora crassa encoding alpha-keto-beta-hydroxylacyl reductoisomerase. Gene 120:115-8
Bowman, B J; Vazquez-Laslop, N; Bowman, E J (1992) The vacuolar ATPase of Neurospora crassa. J Bioenerg Biomembr 24:361-70
Yamaguchi, M; Endo, H; Thordarson, G et al. (1992) Modulation of mouse placental lactogen-I secretion in vitro: effects of progesterone and mouse placental lactogen-II. Endocrinology 130:2897-905

Showing the most recent 10 out of 14 publications