Diabetes mellitus and anal sphincter pressures: an experimental model in rats.
OBJECTIVE
Symptoms of the gastrointestinal tract, frequent in patients with diabetes mellitus, which may be related to an increase in the production of free radicals, include alterations in the function of the sphincter anal musculature. Such alterations are characterized by a decrease of muscular tone associated with different degrees of fecal incontinence. This study was performed to show the alterations in the anal sphincter pressures of diabetic rats and to evaluate the role of nitric oxide and oxidative stress in this situation.


METHODS
Male Wistar rats weighing 250 to 400 g were used. The animals were divided in two groups: control and diabetic. Diabetes was induced through intraperitoneal injection of streptozotocin and the anal pressures were gauged by anorectal manometry. Nitric oxide was evaluated through measures of nitrites and nitrates, and oxidative stress through the technique of chemoluminescence.


RESULTS
There was a significant decrease in the sphincter anal pressure of diabetic animals 60 days after induction (P < 0.05). This pressure returned to basal values after administration of a nitric oxide synthase antagonist. The levels of nitrites and nitrates as well as of lipoperoxidation were significantly increased in the diabetic compared with the control group (P < 0.05).


CONCLUSIONS
In this study, hyperglycemia of diabetes mellitus caused an increase in the oxidative stress. Apparently the elevation of nitric oxide levels was one of the responsible factors for the decrease of anal sphincter pressures.
Fillmann
Henrique Sarubbi
HS
Laboratory of Digestive Physiology, Institute of Basic Health Sciences, Federal University of Rio Grande Do Sul, Lutheran University of Brazil RS, Porto Alegre-RS, Brazil. hfillmann@terra.com.br
Llessuy
Suzana
S
Marroni
Cláudio A
CA
Fillmann
Lúcio S
LS
Marroni
Norma Possa
NP
D001003:Anal Canal / Q000378:metabolism / Q000503:physiopathology*; D000818:Animals; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism / Q000503:physiopathology*; D004195:Disease Models, Animal; D008297:Male; D008365:Manometry; D009123:Muscle Hypotonia / Q000378:metabolism / Q000503:physiopathology*; D009569:Nitric Oxide / Q000502:physiology*; D018384:Oxidative Stress / Q000502:physiology; D011312:Pressure; D051381:Rats; D017208:Rats, Wistar
D009569:Nitric Oxide