ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    Pituitary oxytocin and vasopressin content of rats flown on Cosmos 2044 (1992)
    In:  Other Sources
    Details
    Publication Date: 2011-08-24
    Description: Preliminary studies in rats (COSMOS 1887) suggested that levels of posterior pituitary hormones were reduced by exposure to spaceflight. To confirm these preliminary findings, pituitary tissue from rats flown for 14 days on Cosmos 2044 is obtained. Posterior pituitary content of oxytocin (OT) and vasopressin (VP) were measured in these tissues as well as those from ground-based controls. The synchronous control group had feeding and lighting schedules synchronized to those in the spacecraft and were maintained in flight-type cages. Another group was housed in vivarium cages; a third group was tail suspended (T), a method used to simulate microgravity. Flight rats showed an average reduction of 27 in pituitary OT and VP compared with the three control groups. When hormone content was expressed in terms of pituitary protein (microg hormone/mg protein), the average decrease in OT and VP for the flight animals ranged from 20 to 33 percent compared with the various control groups. Reduced levels of pituitary OT and VP were similar to preliminary measurements from the Cosmos 1887 mission and appear to result from exposure to spaceflight. These data suggest that changes in the rate of hormone secretion or synthesis may have occurred during exposure to microgravity.
    Keywords: LIFE SCIENCES (GENERAL)
    Type: Journal of Applied Physiology, Supplement (ISSN 8750-7587); 73; 2, Au
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 2
    facet.materialart.
    Unknown
    Effect of parathyroidectomy on bone growth and composition in the young rat (1974)
    In:  Other Sources
    Details
    Publication Date: 2011-08-16
    Description: In an effort to determine the influence of the parathyroids on bone growth and composition, 28-day-old male Sprague-Dawley rats were sacrificed 28, 56, and 84 days after parathyroidectomy or sham parathyroidectomy. Body growth as well as femur growth were retarded following parathyroidectomy. Hypocalcemia and hyperphosphatemia occurred in all parathyroidectomized rats; no alterations in plasma magnesium levels were noted. Femur magnesium was increased by 22-30% in the parathyroidectomized rats whereas femur calcium remained unchanged. Bone phosphorus was increased 56 and 84 days following parathyroidectomy. Results of this study indicate that parathyroidectomy retards growth while increasing bone magnesium and phosphorus content.
    Keywords: LIFE SCIENCES (GENERAL)
    Type: Growth; 38; 1974
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 3
    facet.materialart.
    Unknown
    Bone growth and composition in weanling and mature rats exposed to chronic centrifugation (1982)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The primary objective of the study is to determine the effect of continuous exposure to hypergravity on the development and composition of weight-bearing bone. The experimental results are seen to suggest that many, if not all, of the changes observed in bone growth and composition derive from the retarded growth rate of the centrifuged rats. Both centrifuged weanling and mature rats exhibit a significant reduction in femur length and mass. The changes in femur size are more apparent in the weanlings since they are exposed to hypergravity during their most rapid phase of skeletal development. In addition to a slower growth rate, the body mass of the mature and weanling animals is reduced even further by the depletion of body fat. The rapid loss of body fat observed in rats and mice during centrifugation, it is found, can produce a prompt and significant rise in relative femur mass after two weeks of exposure. After adaptation to centrifugation, however, relative femur mass is similar to that of controls at four and eight weeks. At 18 weeks, the centrifuged rats again exhibit an increase in relative femur mass. It is thought that this increase in relative femur mass may be generated by the difference in fat deposition between the 1-G controls and the high-G rats.
    Keywords: LIFE SCIENCES (GENERAL)
    Type: p. S-53
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    Experiment K-6-20. The effect of spaceflight on pituitary oxytocin and vasopressin content of rats (1990)
    In:  CASI
    Details
    Publication Date: 2013-08-31
    Description: Pituitary levels of oxytocin (OT) and vasopressin (AVP) were measured in rats exposed to 12.5 days of spaceflight (FLT) as well as ground-based controls, one group synchronously maintained in flight-type cages with similar feeding schedules (SYN), and one group in vivarium cages (VIV). Flight rats had significantly less (p less than 0.05) pituitary OT and AVP(1.10 plus or minus 0.04 and 1.69 plus or minus 0.07 micron g, n=5) than either the SYN(1.60 plus or minus 0.08 and 2.11 plus or minus 0.04 micron g, n=5) or VIV (1.54 plus or minus 0.03 and 2.10 plus or minus 0.09 micron g, n=5) control groups, respectively. Because the FLT group mean body weight was significantly less (p less than 0.05) than either control group, the pituitary hormone content was also calculated on the basis of posterior pituitary protein content. When calculated in this manner, pituitary OT in the FLT rats (5.09 plus or minus 0.15 micron g/mg protein) was significantly less (p less than 0.05) than SYN(7.66 plus or minus 0.39 micron g/mg protein) or VIV controls (8.11 plus or minus 0.64 micron g/mg protein). Pituitary AVP was also less in the FLT animals (7.80 plus or minus 0.13 micron g/mg protein) compared to either SYN(9.84 plus or minus 0.51, p less than 0.05) or VIV controls (11.01 plus or minus 0.76, p less than 0.05). The reduced levels of pituitary OT and AVP may have resulted from increased hormone secretion resulting from the combined effects of water deprivation and the stress of the novel microgravity environment.
    Keywords: LIFE SCIENCES (GENERAL)
    Type: The US Experiments Flown on the Soviet Biosatellite Cosmos 1887; p 387-392
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    Development of life sciences equipment for microgravity and hypergravity simulation (1994)
    In:  CASI
    Details
    Publication Date: 2013-08-31
    Description: The mission of the Life Science Division at the NASA Ames Research Center is to investigate the effects of gravity on living systems in the spectrum from cells to humans. The range of these investigations is from microgravity, as experienced in space, to Earth's gravity, and hypergravity. Exposure to microgravity causes many physiological changes in humans and other mammals including a headward shift of body fluids, atrophy of muscles - especially the large muscles of the legs - and changes in bone and mineral metabolism. The high cost and limited opportunity for research experiments in space create a need to perform ground based simulation experiments on Earth. Models that simulate microgravity are used to help identify and quantify these changes, to investigate the mechanisms causing these changes and, in some cases, to develop countermeasures.
    Keywords: LIFE SCIENCES (GENERAL)
    Type: NASA. Goddard Space Flight Center, Eighteenth Space Simulation Conference: Space Mission Success Through Testing; p 373-386
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    A metabolic cage for the hindlimb suspended rat (1994)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Hindlimb suspension has been successfully used to simulate the effects of microgravity in rats. The cage and suspension system developed by E. R. Holton is designed to produce a headward shift of fluid and unload the hindlimbs in rodents, causing changes in bone and muscle similar to those in animals and humans exposed to spaceflight. While the Holton suspension system simulates many of the conditions observed in the spaceflight animal, it does not provide for the collection of urine and feces needed to monitor some metabolic activities. As a result, only limited information has been gathered on the nutritional status, and the gastrointestinal and renal function of animals using that model. Although commercial metabolic cages are available, they are usually cylindrical and require a centrally located suspension system and thus, do not readily permit movement of the rats. The limited floor space of commercial cages may affect comparisons with studies using the Holton model which has more than twice the living space of most commercially available cages. To take advantage of the extra living space and extensive data base that has been developed with the Holton model, Holton's cage was modified to make urine and fecal collections possible.
    Keywords: LIFE SCIENCES (GENERAL)
    Type: NASA-TM-108830 , A-94094 , NAS 1.15:108830
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unknown
    RBC-/Cr-51/ half-life and albumin turnover in growing Beagle dogs during chronic radial acceleration (1979)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: The effects of chronic centrifugation on growing Beagle dogs exposed to -2 or -2.6 Gx on albumin and RBC turnover rates, albumin concentration and space, and total blood volume were determined and compared with caged and run control of animals. Albumin-(I-125) and autologous RBC-(Cr-51) preparations were injected into all dogs at day 82 of the centrifugation periods, and the disappearance curves were determined by successive bleedings of the animals over the next 35 d, during which the centrifugation was continued. There were no differences in albumin turnover rates or space. Two populations of RBCs were found in both centrifugated groups, one with a normal half-life of 27 + or - 1 S.E.M. d, and one with a significantly (p less than 0.01) shorter half-life of 15 + or - 2 S.E.M. d. An absolute polycythemia was also observed in both centrifuged groups. The results suggest that chronic centrifugation acts through some as-yet unknown mechanism to affect RBC population kinetics.
    Keywords: LIFE SCIENCES (GENERAL)
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 8
    facet.materialart.
    Unknown
    Studies on the erythron and the ferrokinetic responses in beagles adapted to hypergravity (1978)
    In:  Other Sources
    Details
    Publication Date: 2019-06-27
    Description: Red cell survival, ferrokinetics, and hematologic parameters were investigated in beagle dogs exposed to chronic hypergravity (2.6 Gx). Ineffective erythropoiesis, red cell mass, plasma volume, and Cr-51-elution were significantly increased; maximum Fe-59 incorporation was decreased; and there was no change in the mean erythrocyte life span following autologous injection of Cr-51-labeled red cells and Fe-59-labeled transferrin. Red cell count, F(cells), total body hemoglobin (Hb), susceptability to osmotic lysis, and differential reticulocyte count were increased. White blood cell count, venous blood %Hb, mean cell volume, mean cell Hb, mean cell Hb concentration, and serum iron were decreased. No changes were observed for body mass, mg Fe per g Hb, iron binding capacity, percent saturation of iron carrying capacity, or the electrophoretic mobility of purified Hb. This study indicated that chronic exposure to hypergravity induced changes in red cell size, volume, total mass, and membrane permeability.
    Keywords: LIFE SCIENCES (GENERAL)
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...