Insulin is Not Driving Urinary Bladder Enlargement in Rodent Models of Diabetes

• Published in: The FASEB journal Vol. 36 Suppl 1
• Main Authors: Michel, Martin C, Beltrans-Ornelas, Jesus H, Silva-Velasco, Diana L, Castañeda, Tamara R, Elvert, Ralf, Kannt, Aimo, Xia, Ning, Li, Huige, Arioglu-Inan, Ebru, Centurion, David
• Format: Journal Article
• Language: English
• Published: United States 01.05.2022
• ISSN: 1530-6860
• DOI: 10.1096/fasebj.2022.36.S1.0R858

The urinary bladder is enlarged in all models of type 1 and several of type 2 diabetes (doi 10.1002/nau.23786). We have previously reported that such enlargement is correlated to insulin, but not glucose levels in fructose-fed rats (doi 10.1096/fasebj.2020.34.s1.00542). Because this was surprising, we have now repeated that study and expanded our analysis to other models of diabetes and obesity. Five studies were performed in models of type 2 diabetes and obesity, one in fructose-fed rats (n = 16), one each in ZSF1 rats at age 20 and 28 weeks (a cross between a female Zucker Diabetic Fatty and a male spontaneously hypertensive SHHF rat; n = 30 and 45, respectively), and two in mice on a high-fat diet (n = 23 and 24, respectively). Bladder weight at study end and blood insulin concentrations were subjected to linear correlation analysis based on individual animal data, and data expressed a squared Pearsson correlation coefficient (r ). Animals in the diabetic/obese groups were hyperinsulinemic, whereas bladder enlargement was observed in both studies with ZSF1 rats, the old but not the new in fructose-fed rats, and in neither study with mice on a high-fat diet. Bladder weight and insulin levels were not correlated in the new study in fructose-fed rats or any of the other four studies; the numerical correlation coefficient was negative in two of these studies. When data from all six studies were pooled, a very weak inverse correlation was observed (r 0.0682, descriptive p-value 0.0094; Figure 1). We conclude that, contrary to our previous observation, bladder weight is not positively correlated with insulin levels in rodent models of type 2 diabetes and obesity.