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Rat anterior pituitary hormone cells: responses to variable gravity
K E Shellenberger1, R E Grindeland, W C Hymer
1Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, USA.
Aviation, Space, and Environmental Medicine
|April 25, 2000
Summary
Hypergravity exposure (2G) for 14 days alters growth hormone (GH) cells in rat anterior pituitaries, reducing GH release and changing cell morphology. Prolactin cells remained unaffected, indicating a specific response to hypergravity.
Area of Science:
- Cell biology
- Gravitational biology
- Endocrinology
Background:
- Limited data exists on hypergravity's effects on cells compared to hypogravity.
- This study investigates hypergravity's impact on anterior pituitary cells.
Purpose of the Study:
- To compare the effects of hypergravity (2G) on anterior pituitary cells with existing hypogravity (spaceflight) data.
- To assess functional and morphological changes in pituitary cells after 14 days of centrifugation at 2G.
Main Methods:
- Rats were centrifuged at 2G for 14 days (Cosmos 2G study).
- Anterior pituitary cells were analyzed for function and morphology post-centrifugation.
- Experimental design mirrored a 1989 spaceflight study for direct comparison.
Main Results:
- Growth hormone (GH) cells showed reduced bioactive GH release, even with GHRH stimulation.
- GH-producing cells were smaller and less granulated compared to controls.
- Prolactin-producing cells were not significantly affected by centrifugation.
Conclusions:
- 14-day centrifugation at 2G alters GH cell function and morphology.
- The observed effects on GH cells are specific, as prolactin cells were unaffected.