A study on the effect of Chromium Administration on the Altered Urinary Bladder Reactivity in Experimentally-induced Diabetic Rats

Diabetic-induced urinary bladder dysfunction (diabetic cystopathy) is among the
most common complications of chronic uncontrolled diabetes mellitus. This
cystopathy, involves altered urinary bladder contractility and reactivity, is suggested
to be due to the oxidative stress encountered in diabetes. Chromium, an antioxidant
micronutrient, is proposed nowadays as an adjuvant in some diabetic complications.
Accordingly, this study was designed to evaluate the possible role of oral chromium
administration on the altered urinary bladder reactivity in experimentally-induced
diabetic rats. In the present study, 36 adult male albino rats, weighing 150-180 gm
each, were used. They were divided into 6 equal groups. Group1 (Control group),
Group2 (Cr-treated control group), Group3 (untreated diabetic group), Group4
(Insulin-treated diabetic group), Group5 (Cr-treated diabetic group) and Group6
(Concomitantly insulin & Cr-treated diabetic group). Fasting serum glucose, serum
insulin, homeostatic model assessment to detect insulin resistance (HOMA-IR index),
lipid profile, urinary bladder tissue malondialdehyde (MDA) (a tissue marker of
oxidative stress and lipid peroxidation) and glutathione (GSH) (as an index of the
tissue antioxidant enzyme defense activity) were measured. In addition, the total body
weight, urinary bladder weight and the reactivity of isolated urinary bladder strips to
carbachol (Cch) were determined. The untreated diabetic group exhibited significant
increase of the serum glucose, HOMA-IR index, lipid profile, bladder tissue MDA and
urinary bladder weight, (p<0.05) together with a significant decrease (p<0.05)of
serum insulin, total body weight and bladder tissue GSH level. In addition, the
contractile response of the isolated urinary bladder strips to Cch was significantly
higher in untreated diabetic rats relative to the other tested groups, (p<0.05).
Interestingly, when the diabetic rats were treated with subtherapeutic doses of insulin
alone or oral chromium alone, a significant improvement (p<0.05) of all the altered
parameters was obtained. However, when the diabetic rats were administered
concomitantly with insulin & chromium, a highly significant improvement (p<0.001)
of the deteriorated parameters that have been returned nearly close to the control
level. In conclusion, oral chromium administration has a beneficial effect in
ameliorating the changes in the urinary bladder reactivity in experimentally-induced
diabetic rats, probably through its antioxidant effect and its ability in increasing
insulin sensitivity.