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Secretion of Growth Hormone in Response to Muscle Sensory Nerve StimulationGrowth hormone (GH) secretion is stimulated by aerobic and resistive exercise and inhibited by exposure to actual or simulated (bedrest, hindlimb suspension) microgravity. Moreover, hypothalamic growth hormone-releasing factor (GRF) and preproGRF mRNA are markedly decreased in spaceflight rats. These observations suggest that reduced sensory input from inactive muscles may contribute to the reduced secretion of GH seen in "0 G". Thus, the aim of this study was to determine the effect of muscle sensory nerve stimulation on secretion of GH. Fed male Wistar rats (304 +/- 23 g) were anesthetized (pentobarbital) and the right peroneal (Pe), tibial (T), and sural (S) nerves were cut. Electrical stimulation of the distal (D) or proximal (P) ends of the nerves was implemented for 15 min. to mimic the EMG activity patterns of ankle extensor muscles of a rat walking 1.5 mph. The rats were bled by cardiac puncture and their anterior pituitaries collected. Pituitary and plasma bioactive (BGH) and immunoactive (IGH) GH were measured by bioassay and RIA.
Document ID
20010051286
Document Type
Preprint (Draft being sent to journal)
Authors
Grindeland, Richard E. (NASA Ames Research Center Moffett Field, CA United States)
Roy, R. R. (NASA Ames Research Center Moffett Field, CA United States)
Edgerton, V. R. (NASA Ames Research Center Moffett Field, CA United States)
Gosselink, K. L. (NASA Ames Research Center Moffett Field, CA United States)
Grossman, E. J. (NASA Ames Research Center Moffett Field, CA United States)
Sawchenko, P. E. (NASA Ames Research Center Moffett Field, CA United States)
Wade, Charles E.
Date Acquired
August 20, 2013
Publication Date
January 1, 1994
Subject Category
Aerospace Medicine
Funding Number(s)
PROJECT: RTOP 199-70-12-14
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.