Feeding frequency affects cultured rat pituitary cells in low gravity

Hymer, Wesley C.; Grindeland, R. E.; Salada, T.; Cenci, R.; Krishnan, Kalaiselvan; Mukai, Chiaki; Nagaoka, Shunji

doi:10.1016/0168-1656(96)01373-9

Cited by 12 publications

(7 citation statements)

References 19 publications

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“…2). On the other hand, the decreased PRL secretion observed in pituitary cells in space seems to be a consistent finding [44,45]. PRL levels decreased in the blood of the same four astronauts, thus adding to the hypothesis of an increase in catecholaminergic tone within the CNS (see Fig.…”

Section: The Hypothalamic-pituitary-gonadal Axis (Hpga)supporting

confidence: 54%

Adaptation of the human endocrine system to microgravity in the context of integrative physiology and ageing

Strollo

2000

Pflügers Arch - Eur J Physiol

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This review deals with changes occurring in space in different endocrine systems. Sections are dedicated to hormones involved in bone remodelling, the hypothalamic-pituitary-adrenal axis, the hypothalamicpituitary-thyroid axis, pancreatic hormones, the hypothalamic-pituitary-gonadal axis and the hypothalamicpituitary-somato-mammotropic system. In space, most systems -especially those regulating bone/muscle metabolism and reproduction -undergo changes resembling those observed during senescence, but recover within weeks or months after return. This suggests space as a possible experimental model for the study of "reversible ageing processes". Studying ageing through space technology might give us the opportunity to combine the holistic view of integrative physiology with the most ambitious goal of the present scientific community, i.e. to yield successful ageing by promoting chronic disease prevention studies and by optimizing safe, anti-ageing therapeutic protocols.

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Section: The Hypothalamic-pituitary-gonadal Axis (Hpga)supporting

confidence: 54%

Adaptation of the human endocrine system to microgravity in the context of integrative physiology and ageing

Strollo

2000

Pflügers Arch - Eur J Physiol

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“…The same 3-D aggregates also form in space, and, in fact, this phenomenon was first observed during culture of tissue cell suspensions on space missions (23,47,101). There are numerous examples of different cell types and lineages forming 3-D aggregates during culture in space aboard spacecraft and space stations (23,34,47,101). The fact that these novel 3-D aggregates are formed both in space and in the RWV culture apparatus points to the similarities between the two growth environments.…”

Section: Rotating-wall Vessel Culture Apparatus and The Low-shear Modmentioning

confidence: 86%

“…Accordingly, the 3-D aggregates are physiologically relevant in vitro tissue models and are currently being engineered for use in infectious-disease research, tissue transplantation, and other fundamental biomedical applications (34, 80, . The same 3-D aggregates also form in space, and, in fact, this phenomenon was first observed during culture of tissue cell suspensions on space missions (23,47,101). There are numerous examples of different cell types and lineages forming 3-D aggregates during culture in space aboard spacecraft and space stations (23,34,47,101).…”

Section: Rotating-wall Vessel Culture Apparatus and The Low-shear Modmentioning

confidence: 91%

Microbial Responses to Microgravity and Other Low-Shear Environments

Nickerson

Ott

Wilson

et al. 2004

Microbiol Mol Biol Rev

328

348

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Microbial adaptation to environmental stimuli is essential for survival. While several of these stimuli have been studied in detail, recent studies have demonstrated an important role for a novel environmental parameter in which microgravity and the low fluid shear dynamics associated with microgravity globally regulate microbial gene expression, physiology, and pathogenesis. In addition to analyzing fundamental questions about microbial responses to spaceflight, these studies have demonstrated important applications for microbial responses to a ground-based, low-shear stress environment similar to that encountered during spaceflight. Moreover, the low-shear growth environment sensed by microbes during microgravity of spaceflight and during ground-based microgravity analogue culture is relevant to those encountered during their natural life cycles on Earth. While no mechanism has been clearly defined to explain how the mechanical force of fluid shear transmits intracellular signals to microbial cells at the molecular level, the fact that cross talk exists between microbial signal transduction systems holds intriguing possibilities that future studies might reveal common mechanotransduction themes between these systems and those used to sense and respond to low-shear stress and changes in gravitation forces. The study of microbial mechanotransduction may identify common conserved mechanisms used by cells to perceive changes in mechanical and/or physical forces, and it has the potential to provide valuable insight for understanding mechanosensing mechanisms in higher organisms. This review summarizes recent and future research trends aimed at understanding the dynamic effects of changes in the mechanical forces that occur in microgravity and other low-shear environments on a wide variety of important microbial parameters

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“…immunoassay; bioassay; proprioception; electrical stimulation; peripheral nerves; low-threshold afferents GROWTH HORMONE (GH) is the most abundant hormone in the anterior pituitary gland of nonlactating mammals (18) and consists of a family of Ͼ100 molecular forms that vary in size and possibly function (2)(3)(4)28). Variants of GH range from fragments as small as 5 kDa to large-molecular-weight forms (''big'' and ''big big'' GH) which can be Ͼ100 kDa in size (3,4,18,28). The 22-kDa product of the GH-N gene is the GH most commonly measured by immunoassay, and it is the form made by recombinant DNA technologies and used therapeutically for a variety of growth-related disorders.…”

mentioning

confidence: 99%

“…Secretion of bGH by pituitary cells cultured from rats exposed to spaceflight or by rat pituitary cells flown in space in culture is consistently decreased (ϳ50%), whereas the iGH response is variable (17)(18)(19). These changes in bGH occur in the presence of normal levels of plasma metabolites that are thought to regulate iGH secretion.…”

mentioning

confidence: 99%

Skeletal muscle afferent regulation of bioassayable growth hormone in the rat pituitary

Gosselink¹,

Grindeland

Roy

et al. 1998

Journal of Applied Physiology

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There are forms of growth hormone (GH) in the plasma and pituitary of the rat and in the plasma of humans that are undetected by presently available immunoassays (iGH) but can be measured by bioassay (bGH). Although the regulation of iGH release is well documented, the mechanism(s) of bGH release is unclear. On the basis of changes in bGH and iGH secretion in rats that had been exposed to microgravity conditions, we hypothesized that neural afferents play a role in regulating the release of these hormones. To examine whether bGH secretion can be modulated by afferent input from skeletal muscle, the proximal or distal ends of severed hindlimb fast muscle nerves were stimulated ( approximately 2 times threshold) in anesthetized rats. Plasma bGH increased approximately 250%, and pituitary bGH decreased approximately 60% after proximal nerve trunk stimulation. The bGH response was independent of muscle mass or whether the muscles were flexors or extensors. Distal nerve stimulation had little or no effect on plasma or pituitary bGH. Plasma iGH concentrations were unchanged after proximal nerve stimulation. Although there may be multiple regulatory mechanisms of bGH, the present results demonstrate that the activation of low-threshold afferents from fast skeletal muscles can play a regulatory role in the release of bGH, but not iGH, from the pituitary in anesthetized rats.

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Feeding frequency affects cultured rat pituitary cells in low gravity

Cited by 12 publications

References 19 publications

Adaptation of the human endocrine system to microgravity in the context of integrative physiology and ageing

Adaptation of the human endocrine system to microgravity in the context of integrative physiology and ageing

Microbial Responses to Microgravity and Other Low-Shear Environments

Skeletal muscle afferent regulation of bioassayable growth hormone in the rat pituitary

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