R M Ortiz

Summary

Affiliation: University of California
Country: USA

Publications

  1. ncbi request reprint Osmoregulation in marine mammals
    R M Ortiz
    Department of Biology, University of California, Santa Cruz, CA 95064, USA
    J Exp Biol 204:1831-44. 2001
  2. ncbi request reprint A new perspective on adiposity in a naturally obese mammal
    R M Ortiz
    Department of Biology, University of California, Santa Cruz, Santa Cruz, California 95064, USA
    Am J Physiol Endocrinol Metab 281:E1347-51. 2001
  3. ncbi request reprint Hormonal changes associated with the transition between nursing and natural fasting in northern elephant seals (Mirounga angustirostris)
    Rudy M Ortiz
    Department of Biology, University of California, Santa Cruz, CA 95064, USA
    Gen Comp Endocrinol 130:78-83. 2003
  4. ncbi request reprint Body water handling in response to hypertonic-saline induced diuresis in fasting northern elephant seal pups (Mirounga angustirostris)
    Rudy M Ortiz
    Department of Biology, University of California, CA 95064, Santa Cruz, USA
    Comp Biochem Physiol A Mol Integr Physiol 134:423-8. 2003
  5. ncbi request reprint Effects of acute fresh water exposure on water flux rates and osmotic responses in Kemp's ridley sea turtles (Lepidochelys kempi)
    R M Ortiz
    NASA Ames Research Center, MS 239 11, Moffett Field, CA 94035, USA
    Comp Biochem Physiol A Mol Integr Physiol 127:81-7. 2000
  6. ncbi request reprint Effects of capture on adrenal steroid and vasopressin concentrations in free-ranging bottlenose dolphins (Tursiops truncatus)
    R M Ortiz
    Department of Marine Biology, Physiological Ecology and Bioenergetics Lab, Texas A and M University at Galveston, Galveston, TX 77551, USA
    Comp Biochem Physiol A Mol Integr Physiol 125:317-24. 2000
  7. ncbi request reprint Acutely elevated vasopressin increases circulating concentrations of cortisol and aldosterone in fasting northern elephant seal (Mirounga angustirostris) pups
    Rudy M Ortiz
    Department of Biology, University of California, Santa Cruz, 95064, USA
    J Exp Biol 206:2795-802. 2003
  8. ncbi request reprint Effects of prolonged fasting on plasma cortisol and TH in postweaned northern elephant seal pups
    R M Ortiz
    Department of Biology, University of California, Santa Cruz, California 95064, USA
    Am J Physiol Regul Integr Comp Physiol 280:R790-5. 2001
  9. ncbi request reprint Estimation of water turnover rates of captive West Indian manatees (Trichechus manatus) held in fresh and salt water
    R M Ortiz
    Physiological Ecology and Bioenergetics Research Laboratory, Texas A and M University at Galveston, Galveston, TX 77551, USA
    J Exp Biol 202:33-8. 1999
  10. ncbi request reprint Renal effects of fresh water-induced hypo-osmolality in a marine adapted seal
    R M Ortiz
    A316 Earth and Marine Sciences, Department of Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
    J Comp Physiol B 172:297-307. 2002

Collaborators

Detail Information

Publications17

  1. ncbi request reprint Osmoregulation in marine mammals
    R M Ortiz
    Department of Biology, University of California, Santa Cruz, CA 95064, USA
    J Exp Biol 204:1831-44. 2001
    ..The antidiuretic role of vasopressin remains inconclusive in marine mammals, while the natriuretic function of atrial natriuretic peptide has yet to be examined. Ideas on the direction of future studies are presented...
  2. ncbi request reprint A new perspective on adiposity in a naturally obese mammal
    R M Ortiz
    Department of Biology, University of California, Santa Cruz, Santa Cruz, California 95064, USA
    Am J Physiol Endocrinol Metab 281:E1347-51. 2001
    ..The lack of a correlation between leptin and FM may reflect the different functions of fat between terrestrial and marine mammals...
  3. ncbi request reprint Hormonal changes associated with the transition between nursing and natural fasting in northern elephant seals (Mirounga angustirostris)
    Rudy M Ortiz
    Department of Biology, University of California, Santa Cruz, CA 95064, USA
    Gen Comp Endocrinol 130:78-83. 2003
    ....
  4. ncbi request reprint Body water handling in response to hypertonic-saline induced diuresis in fasting northern elephant seal pups (Mirounga angustirostris)
    Rudy M Ortiz
    Department of Biology, University of California, CA 95064, Santa Cruz, USA
    Comp Biochem Physiol A Mol Integr Physiol 134:423-8. 2003
    ..This water recycling mechanism may allow pups to avoid negative perturbations in body water as they initiate feeding in a marine environment following the fast...
  5. ncbi request reprint Effects of acute fresh water exposure on water flux rates and osmotic responses in Kemp's ridley sea turtles (Lepidochelys kempi)
    R M Ortiz
    NASA Ames Research Center, MS 239 11, Moffett Field, CA 94035, USA
    Comp Biochem Physiol A Mol Integr Physiol 127:81-7. 2000
    ..The lack of a change in adrenocorticoids to acute fresh water exposure suggests that adrenal responsiveness to an hypo-osmotic environment may be delayed in marine turtles when compared to marine mammals...
  6. ncbi request reprint Effects of capture on adrenal steroid and vasopressin concentrations in free-ranging bottlenose dolphins (Tursiops truncatus)
    R M Ortiz
    Department of Marine Biology, Physiological Ecology and Bioenergetics Lab, Texas A and M University at Galveston, Galveston, TX 77551, USA
    Comp Biochem Physiol A Mol Integr Physiol 125:317-24. 2000
    ..The study suggests that (1) a typical hypothalamic-pituitary-adrenal axis is present in these animals, and (2) the relatively short capture and restraint times did not induce a significant neuroendocrine stress response...
  7. ncbi request reprint Acutely elevated vasopressin increases circulating concentrations of cortisol and aldosterone in fasting northern elephant seal (Mirounga angustirostris) pups
    Rudy M Ortiz
    Department of Biology, University of California, Santa Cruz, 95064, USA
    J Exp Biol 206:2795-802. 2003
    ..Therefore, under natural fasting conditions, pups may be highly sensitive to small changes in [VP], resulting in the maintenance of water and electrolyte balance...
  8. ncbi request reprint Effects of prolonged fasting on plasma cortisol and TH in postweaned northern elephant seal pups
    R M Ortiz
    Department of Biology, University of California, Santa Cruz, California 95064, USA
    Am J Physiol Regul Integr Comp Physiol 280:R790-5. 2001
    ....
  9. ncbi request reprint Estimation of water turnover rates of captive West Indian manatees (Trichechus manatus) held in fresh and salt water
    R M Ortiz
    Physiological Ecology and Bioenergetics Research Laboratory, Texas A and M University at Galveston, Galveston, TX 77551, USA
    J Exp Biol 202:33-8. 1999
    ..Manatees in fresh water drank large volumes of water, which may make them susceptible to hyponatremia if access to a source of Na+ is not provided...
  10. ncbi request reprint Renal effects of fresh water-induced hypo-osmolality in a marine adapted seal
    R M Ortiz
    A316 Earth and Marine Sciences, Department of Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
    J Comp Physiol B 172:297-307. 2002
    ..Urea excretion appears to be a significant mechanism by which NES pups sustain electrolyte resorption during conditions that can negatively affect ionic homeostasis such as prolonged fasting...
  11. ncbi request reprint Deposition and renal handling of urinary electrolytes from rats during spaceflight
    C E Wade
    Life Science Division, NASA Ames Research Center, Moffett Field, CA 94035, USA
    J Gravit Physiol 6:25-31. 1999
    ..Deposition of urine on all surfaces of the cages during spaceflight should be considered in the design of future animal habitats, and in future analyses of waste pad constituents...
  12. ncbi request reprint GH and ghrelin increase with fasting in a naturally adapted species, the northern elephant seal (Mirounga angustirostris)
    R M Ortiz
    Department of Biology, University of California, Santa Cruz, California 95064, USA
    J Endocrinol 178:533-9. 2003
    ..The increases in cortisol, ghrelin, glucagon, and GH suggest that these hormones may be integral in mediating the metabolism of seal pups during prolonged fasting...
  13. ncbi request reprint Osmoregulation in wild and captive West Indian manatees (Trichechus manatus)
    R M Ortiz
    Department of Marine Biology, Texas A and M University Galveston, 77551, USA
    Physiol Zool 71:449-57. 1998
    ..Vasopressin levels appear to be osmotically mediated in manatees as in other mammals...
  14. ncbi request reprint Urinary excretion of LH and testosterone from male rats during exposure to increased gravity: post-spaceflight and centrifugation
    R M Ortiz
    Life Science Division, NASA Ames Research Center, MS 239 11, Moffett Field, California 94035, USA
    Proc Soc Exp Biol Med 225:98-102. 2000
    ..The previous dissociation between plasma LH and T during altered gravity was not observed in the present study in which excreted LH and T were measured...
  15. ncbi request reprint Thyroid hormone concentrations in captive and free-ranging West Indian manatees (Trichechus manatus)
    R M Ortiz
    Physiological Ecology and Bioenergetics Laboratory, Texas A and M University, Galveston, TX 77551, USA
    J Exp Biol 203:3631-7. 2000
    ....
  16. ncbi request reprint Estradiol and testosterone concentrations increase with fasting in weaned pups of the northern elephant seal (Mirounga angustirostris)
    R A Sherman-Cooney
    Department of Biology, University of California, Santa Cruz, CA, 95064, USA
    Physiol Biochem Zool 78:55-9. 2005
    ..Therefore, compensatory mechanisms may exist that alleviate the fasting-induced inhibition of gonadal steroidogenesis during neonatal development in elephant seal pups...
  17. ncbi request reprint Increases in body mass of rats during spaceflight: models and measurements
    C E Wade
    Life Sciences Division, NASA Ames Research Center, Moffett Field, CA 94035 1000, USA
    Aviat Space Environ Med 71:1126-30. 2000
    ..The increase in body mass during spaceflight suggests that the rat may provide a viable model for metabolic studies in which changes during spaceflight may be predicted in part by ground-based hypergravity studies...