Functional and morphological changes in endocrine pancreas following cola drink consumption in rats.

Abstract

AIM:

We report the effects of long-term cola beverage drinking on glucose homeostasis, endocrine pancreas function and morphology in rats.

METHODS:

Wistar rats drank: water (group W), regular cola beverage (group C, sucrose sweetened) or "light" cola beverage (group L, artificially sweetened). After 6 months, 50% of the animals in each group were euthanized and the remaining animals consumed water for the next 6 months when euthanasia was performed. Biochemical assays, insulinemia determination, estimation of insulin resistance (HOMA-IR), morphometry and immunohistochemistry evaluations were performed in pancreas.

RESULTS:

Hyperglycemia (16%, p<0.05), CoQ10 (coenzyme-Q10) decrease (-52%,p<0.01), strong hypertriglyceridemia (2.8-fold, p<0.01), hyperinsulinemia (2.4 fold, p<0.005) and HOMA-IR increase (2.7 fold, p<0.01) were observed in C. Group C showed a decrease in number of α cells (-42%, p<0.01) and β cells (-58%, p<0.001) and a moderate increase in α cells' size after wash-out (+14%, p<0.001). Group L showed reduction in β cells' size (-9%, p<0.001) and only after wash-out (L12) a 19% increase in size (p<0.0001) with 35% decrease in number of α cells (p<0.01). Groups C and L showed increase in α/β-cell ratio which was irreversible only in C (α/β = +38% in C6,+30% in C12, p<0.001vs.W6). Regular cola induced a striking increase in the cytoplasmic expression of Trx1 (Thioredoxin-1) (2.25-fold in C6 vs. W6; 2.7-fold in C12 vs. W12, p<0.0001) and Prx2 (Peroxiredoxin-2) (3-fold in C6 vs. W6; 2-fold in C12 vs. W12, p<0.0001). Light cola induced increase in Trx1 (3-fold) and Prx2 (2-fold) after wash-out (p<0.0001, L12 vs. W12).

CONCLUSION:

Glucotoxicity may contribute to the loss of β cell function with depletion of insulin content. Oxidative stress, suggested by increased expression of thioredoxins and low circulating levels of CoQ10, may follow sustained hyperglycemia. A likely similar panorama may result from the effects of artificially sweetened cola though via other downstream routes.

• Authors: Matilde Otero-Losada, Gabriel Cao, Julián González, Angélica Muller, Graciela Ottaviano, Christopher Lillig, Francisco Capani, Giuseppe Ambrosio, José Milei
• Journal: PloS one (PLoS One) Vol. 10 Issue 3 Pg. e0118700 ( 2015) ISSN: 1932-6203 [Electronic] United States
• PMID: 25790473 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Blood Glucose
• Triglycerides
• Ubiquinone
• coenzyme Q10

Topics

• Analysis of Variance
• Animals
• Blood Glucose (metabolism)
• Carbonated Beverages (adverse effects, analysis)
• Cola (chemistry)
• Immunohistochemistry
• Insulin Resistance (physiology)
• Islets of Langerhans (drug effects, pathology)
• Oxidative Stress (drug effects)
• Rats
• Triglycerides (blood)
• Ubiquinone (analogs & derivatives, metabolism)