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Rudy M Ortiz Lab

Northern Elephant Seal Pups

Seal Pup


My dissertation research examined renal function and hormonal regulation of metabolism in postweaned northern elephant seal pups. Because elephant seal pups have adapted to fasting for 2.5 - 3 months postweaning, they provide an interesting model to address the issues of water and electrolyte homeostasis and endocrine regulation during a protracted fasting period. Some data exists on renal function and endocrine changes during periods of food restriction and fasting in pinnipeds, however some of these data are not conclusive and the physiological mechanisms involved are not well defined. Our previous data showed a decrease in plasma vasopressin (AVP) along with a decrease in urine output and increased urine osmolality. This apparent paradox in AVP concentrations and urine output was addressed in my dissertation research including a more thorough evaluation of how osmoregulatory hormones contribute to water and electrolyte balance during exogenous manipulations by volume-, water- and salt-loading.

View Publications

Ortiz, R.M., S.H. Adams, D.P. Costa and C.L. Ortiz. 1996. Plasma vasopressin levels and water conservation in fasting, postweaned northern elephant seal pups (Mirounga angustirostris). (pdf 412 Kb) Marine Mammal Science 12(1):99-106.