Bone resorption and mineral excretion in rats during spaceflight
The American Journal of Physiology
|March 1, 1983
Summary
Spaceflight did not significantly alter bone resorption in rats after 20 days. A slight decrease may be linked to reduced calcium turnover, with increased mineral and electrolyte excretion observed.
Area of Science:
- Space biology
- Skeletal physiology
- Mineral metabolism
Background:
- Spaceflight is known to affect bone metabolism, particularly bone formation.
- Understanding bone resorption changes during spaceflight is crucial for astronaut health.
Purpose of the Study:
- To directly measure bone resorption in rats during spaceflight.
- To investigate the relationship between bone resorption, calcium turnover, and mineral excretion in space.
Main Methods:
- Direct measurement of bone resorption using continuous tracer administration (40Ca).
- Neutron activation analysis to quantify 48Ca released from the skeleton.
- Comparison of in-flight rats with synchronous ground controls during COSMOS 1129.
Main Results:
- No significant large change in bone resorption was detected after 20 days of spaceflight.
- A 20-25% decrease in resorption is suggested, likely secondary to reduced total body calcium turnover.
- Excretion of sodium, potassium, and zinc increased significantly during flight.
Conclusions:
- Bone resorption appears more stable than bone formation during short-term spaceflight.
- Decreased calcium turnover and increased mineral/electrolyte excretion are key physiological responses to spaceflight in rats.
Keywords:
NASA Experiment Number COS 1129-11More Related Videos
04:24Proper Positioning and Restraint of a Rat Hind Limb for Focused High Resolution Imaging of Bone Micro-architecture Using In Vivo Micro-computed Tomography
Published on: November 22, 2017
05:25Using Inducible Osteoblastic Lineage-Specific Stat3 Knockout Mice to Study Alveolar Bone Remodeling During Orthodontic Tooth Movement
Published on: July 21, 2023
Related Concept Videos
01:40Bone Remodeling
Bone remodeling is a continuous and balanced process of bone resorption by osteoclasts and bone formation by osteoblasts. In adults, it helps maintain bone mass and calcium homeostasis. While mechanical stress can stimulate turnover as part of the normal maintenance and reparative process, several hormones also regulate bone remodeling.
01:31Osteoclasts in Bone Remodeling
Osteoclasts are cells responsible for bone resorption and remodeling. They originate from hematopoietic progenitor cells present in the bone marrow. Numerous progenitor cells fuse to form multinucleated cells, each with 10-20 nuclei. A single osteoclast has a diameter of 150 to 200 µM. These cells have ruffled borders that break down the underlying bone tissue and release minerals such as calcium into the blood in bone resorption. Osteoclasts cling to bones with their ruffled edges during bone...
01:18The Bone Matrix
Bone contains a relatively small number of cells entrenched in a matrix of collagen fibers that provide an adherent surface for inorganic salt crystals. Both components of the matrix, organic and inorganic, contribute to the unusual properties of bone. Without collagen, bones would be brittle and shatter easily. Without mineral crystals, bones would flex and provide little support. This can be observed by an experiment: when the minerals of a bone are dissolved by soaking the bone in acid or...
01:29Bone Disorders
Aging and its effect on bone remodeling is the most common cause of bone disorders. In young and healthy people, bone deposition and resorption happen at an equal rate to maintain optimal bone health.
Bone deposition is also affected by the levels of sex hormones like estrogen and testosterone that promote osteoblast activity and bone matrix synthesis. When the level of these hormones decreases due to aging, it causes a reduction in bone deposition. As a result, bone resorption by osteoclasts...
Bone deposition is also affected by the levels of sex hormones like estrogen and testosterone that promote osteoblast activity and bone matrix synthesis. When the level of these hormones decreases due to aging, it causes a reduction in bone deposition. As a result, bone resorption by osteoclasts...
01:31Essential Minerals for Bone Health
The minerals contained in all of the food we consume are essential for our organ systems. However, certain essential minerals, such as calcium, phosphorus, magnesium, manganese, and fluoride, largely affect bone health.
Calcium and Phosphorus
Calcium is a critical component of bones, especially in the form of calcium phosphate and calcium carbonate. Since the body cannot make calcium, it must be obtained from the diet. However, calcium cannot be absorbed from the small intestine without...
Calcium and Phosphorus
Calcium is a critical component of bones, especially in the form of calcium phosphate and calcium carbonate. Since the body cannot make calcium, it must be obtained from the diet. However, calcium cannot be absorbed from the small intestine without...