Limits...
Monosodium Glutamate Dietary Consumption Decreases Pancreatic β-Cell Mass in Adult Wistar Rats.

Boonnate P, Waraasawapati S, Hipkaeo W, Pethlert S, Sharma A, Selmi C, Prasongwattana V, Cha'on U - PLoS ONE (2015)

Bottom Line: We investigated the morphological and functional effects of prolonged MSG consumption on rat glucose metabolism and on pancreatic islet histology.Daily MSG dietary consumption was associated with reduced pancreatic β-cell mass and enhanced hemorrhages and fibrosis, but did not affect glucose homeostasis.We speculate that high dietary MSG intake may exert a negative effect on the pancreas and such effect might become functionally significant in the presence or susceptibility to diabetes or NaCl; future experiments will take these crucial cofactors into account.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.

ABSTRACT

Background: The amount of dietary monosodium glutamate (MSG) is increasing worldwide, in parallel with the epidemics of metabolic syndrome. Parenteral administration of MSG to rodents induces obesity, hyperglycemia, hyperlipidemia, insulin resistance, and type 2 diabetes. However, the impact of dietary MSG is still being debated. We investigated the morphological and functional effects of prolonged MSG consumption on rat glucose metabolism and on pancreatic islet histology.

Methods: Eighty adult male Wistar rats were randomly subdivided into 4 groups, and test rats in each group were supplemented with MSG for a different duration (1, 3, 6, or 9 months, n=20 for each group). All rats were fed ad libitum with a standard rat chow and water. Ten test rats in each group were provided MSG 2 mg/g body weight/day in drinking water and the 10 remaining rats in each group served as non-MSG treated controls. Oral glucose tolerance tests (OGTT) were performed and serum insulin measured at 9 months. Animals were sacrificed at 1, 3, 6, or 9 months to examine the histopathology of pancreatic islets.

Results: MSG-treated rats had significantly lower pancreatic β-cell mass at 1, 6 and 9 months of study. Islet hemorrhages increased with age in all groups and fibrosis was significantly more frequent in MSG-treated rats at 1 and 3 months. Serum insulin levels and glucose tolerance in MSG-treated and untreated rats were similar at all time points we investigated.

Conclusion: Daily MSG dietary consumption was associated with reduced pancreatic β-cell mass and enhanced hemorrhages and fibrosis, but did not affect glucose homeostasis. We speculate that high dietary MSG intake may exert a negative effect on the pancreas and such effect might become functionally significant in the presence or susceptibility to diabetes or NaCl; future experiments will take these crucial cofactors into account.

No MeSH data available.


Related in: MedlinePlus

Islet size (um2) distribution in control and MSG-treated groups at 1, 3, 6, and 9 months.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4487683&req=5

pone.0131595.g005: Islet size (um2) distribution in control and MSG-treated groups at 1, 3, 6, and 9 months.

Mentions: Hemorrhages in the pancreatic islets were observed in both control and MSG-supplemented groups in 4/10 and 7/10 rats at 1 month, 8/10 and 9/10at 3 months, 10/10 in both groups at 6 and 9 months, respectively (Fig 2). However, differences were not significant between the groups throughout the study period. Pancreatic islet fibrosis also increased with age in both groups but was more prominent in the MSG-treated group at 1 and 3 months of the study(P< 0.0001) (Fig 3). The β-cell areas in the pancreatic islets were significantly lower in the MSG-treated group compared with controls at 1, 6 and 9 months (P< 0.05) (Fig 4). Pancreatic islet size distribution in the MSG-treated group was significantly higher than that of the control groups at 1 month (Fig 5) but was similar in both groups throughout the remaining period. The islet density of MSG-treated group was significantly higher compared to controls at 6 months (0.58 ± 0.12 vs. 0.42 ± 0.07; P <0.05), but such difference was not seen in any other time points (Fig 6). The intensity of immune-staining of 4-HNE, an oxidative stress marker, in the pancreatic islets of the MSG-treated group was slightly (but not significantly) higher at 1 month and was significantly higher at 6 months compared to the control group (P = 0.001) (Fig 7).


Monosodium Glutamate Dietary Consumption Decreases Pancreatic β-Cell Mass in Adult Wistar Rats.

Boonnate P, Waraasawapati S, Hipkaeo W, Pethlert S, Sharma A, Selmi C, Prasongwattana V, Cha'on U - PLoS ONE (2015)

Islet size (um2) distribution in control and MSG-treated groups at 1, 3, 6, and 9 months.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4487683&req=5

pone.0131595.g005: Islet size (um2) distribution in control and MSG-treated groups at 1, 3, 6, and 9 months.
Mentions: Hemorrhages in the pancreatic islets were observed in both control and MSG-supplemented groups in 4/10 and 7/10 rats at 1 month, 8/10 and 9/10at 3 months, 10/10 in both groups at 6 and 9 months, respectively (Fig 2). However, differences were not significant between the groups throughout the study period. Pancreatic islet fibrosis also increased with age in both groups but was more prominent in the MSG-treated group at 1 and 3 months of the study(P< 0.0001) (Fig 3). The β-cell areas in the pancreatic islets were significantly lower in the MSG-treated group compared with controls at 1, 6 and 9 months (P< 0.05) (Fig 4). Pancreatic islet size distribution in the MSG-treated group was significantly higher than that of the control groups at 1 month (Fig 5) but was similar in both groups throughout the remaining period. The islet density of MSG-treated group was significantly higher compared to controls at 6 months (0.58 ± 0.12 vs. 0.42 ± 0.07; P <0.05), but such difference was not seen in any other time points (Fig 6). The intensity of immune-staining of 4-HNE, an oxidative stress marker, in the pancreatic islets of the MSG-treated group was slightly (but not significantly) higher at 1 month and was significantly higher at 6 months compared to the control group (P = 0.001) (Fig 7).

Bottom Line: We investigated the morphological and functional effects of prolonged MSG consumption on rat glucose metabolism and on pancreatic islet histology.Daily MSG dietary consumption was associated with reduced pancreatic β-cell mass and enhanced hemorrhages and fibrosis, but did not affect glucose homeostasis.We speculate that high dietary MSG intake may exert a negative effect on the pancreas and such effect might become functionally significant in the presence or susceptibility to diabetes or NaCl; future experiments will take these crucial cofactors into account.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.

ABSTRACT

Background: The amount of dietary monosodium glutamate (MSG) is increasing worldwide, in parallel with the epidemics of metabolic syndrome. Parenteral administration of MSG to rodents induces obesity, hyperglycemia, hyperlipidemia, insulin resistance, and type 2 diabetes. However, the impact of dietary MSG is still being debated. We investigated the morphological and functional effects of prolonged MSG consumption on rat glucose metabolism and on pancreatic islet histology.

Methods: Eighty adult male Wistar rats were randomly subdivided into 4 groups, and test rats in each group were supplemented with MSG for a different duration (1, 3, 6, or 9 months, n=20 for each group). All rats were fed ad libitum with a standard rat chow and water. Ten test rats in each group were provided MSG 2 mg/g body weight/day in drinking water and the 10 remaining rats in each group served as non-MSG treated controls. Oral glucose tolerance tests (OGTT) were performed and serum insulin measured at 9 months. Animals were sacrificed at 1, 3, 6, or 9 months to examine the histopathology of pancreatic islets.

Results: MSG-treated rats had significantly lower pancreatic β-cell mass at 1, 6 and 9 months of study. Islet hemorrhages increased with age in all groups and fibrosis was significantly more frequent in MSG-treated rats at 1 and 3 months. Serum insulin levels and glucose tolerance in MSG-treated and untreated rats were similar at all time points we investigated.

Conclusion: Daily MSG dietary consumption was associated with reduced pancreatic β-cell mass and enhanced hemorrhages and fibrosis, but did not affect glucose homeostasis. We speculate that high dietary MSG intake may exert a negative effect on the pancreas and such effect might become functionally significant in the presence or susceptibility to diabetes or NaCl; future experiments will take these crucial cofactors into account.

No MeSH data available.


Related in: MedlinePlus