Effects of spaceflight on the mouse submandibular gland

Abstract

Objective: This study was conducted to determine if the morphology and biochemistry of the mouse submandibular gland is affected by microgravity and the spaceflight environment.Design: Tissues from female mice flown on the US space shuttle missions Space Transportation System (STS)-131 and STS-135 for 15 and 13 d, respectively, and from male mice flown on the 30 d Russian Bion-M1 biosatellite, were examined using transmission electron microscopy and light and electron microscopic immunohistochemistry. Results:In contrast to the parotid gland, morphologic changes were not apparent in the submandibular gland. No significant changes in protein expression, as assessed by quantitative immunogold labeling, occurred in female mice flown for 13-15 d. In male mice, however, increased labeling for salivary androgen binding protein alpha (in acinar cell secretory granules), and epidermal growth factor and nerve growth factor (in granular convoluted duct cell granules) was seen after 30 d in space. Conclusion:These results indicate that spaceflight alters secretory protein expression in the submandibular gland and suggest that the sex of the animals and the length of the flight may affect the response. These findings also show that individual salivary glands respond differently to spaceflight. Saliva contains proteins secreted from salivary glands and is easily collected, therefore is a useful biofluid for general medical analyses and in particular for monitoring the physiology and health of astronauts.

Craniofacial Bones and Teeth in Spacefarers: Systematic Review and Meta-analysis

“…In the CRS-10 mission, incisors of SF animals demonstrated an increase in pulp area with a corresponding decrease in hard tissue area in cross-sectional samples, which may be suggestive of altered morphology ( Maupin et al 2019 ). Moreover, changes in salivary glands have been described in spacefarers, which may also contribute to microgravity-induced changes in teeth, as saliva is well known for its protective function ( Hand et al 2020 ). Thus, more data are needed to fully understand the effect of spaceflight on teeth structure.…”

Short-term head-down bed rest microgravity simulation alters salivary microbiome in young healthy men

“…To the best of our knowledge, oral microorganisms are closely associated with oral diseases such as caries ( Dinis et al, 2022 ), periodontitis ( Plachokova et al, 2021 ), and oral cancer ( Zhang et al, 2019 ); they are also involved in various systemic diseases such as diabetes ( Matsha et al, 2020 ), Alzheimer’s disease ( Dominy et al, 2019 ), pancreatic cancer ( Fan et al, 2018 ), and colorectal cancer ( Wang et al, 2021 ). Previous and recent studies have also suggested that oral soft and hard tissues, including salivary glands ( Groza et al, 1981 , 1983 ; Mednieks and Hand, 1987 ; Mednieks et al, 2014 ; Dagdeviren et al, 2018a ; Hand et al, 2020 ), mandibles ( Simmons et al, 1983 ; Ghosh et al, 2016 ; Dagdeviren et al, 2018b ), and teeth ( Rosenberg et al, 1984 ; Dagdeviren et al, 2018b ), are affected by spaceflight. The risk of dental diseases, such as caries and periodontitis, increases in a microgravity environment ( Rai and Kaur, 2011 ).…”

Smooth Muscle Actin as a Criterion for Gravisensitivity of Stomach and Jejunum in Laboratory Rodents

“…The digestive system is highly sensitive to space flight factors, which can limit the functionality of astronauts on board the ISS [9]. As reported, significant changes occur in the digestive organs under space flight conditions [8][9][10][11], including a decreased evacuation function of the gastric contents, an increased content of gastric fluid, and an expansion of the intestine, which indicate an increased secretory activity in the organs [1]. In addition, studies have revealed structural changes in the mucosa and other layers of the stomach and intestines, resulting in a risk of progressive accumulation of changes at the tissue level up to the formation of morphological signs of atrophy and a loss of muscle mass [12][13][14][15].…”