Diabetes Mellitus by Repeated Stress in Rats Bearing Chemical Diabetes

Abstract

Rats with chemical diabetes were submitted to repeated restraint in order to investigate the diabetogenic potentiality of stress. Material and MethodUnfasted, adult Sprague-Dawley rats of about 150 g initial b.w. were employed. Blood and urine glucose determinations were performed by the glucose oxidase strip method (Vargas, Bronfman and Kawada 1974). Basal glycemia for normal rats was 92 + 0.6 mg% (M + SEM of 104 determinations). The samples were taken immediately before stress (time 0), every 60 min along 240 minutes. Restraint stress was provoked by immobilization of the rats on the operating table by moans of rubber bands tied to their extremities, procedure that permits escape movements.Two series of rats, 67 with 80% pancreatectomy and 14 with 90 % pancreatectomy (80%-P~ and 90%-P~), were submitted to repeated restraint stress. The stress began 7 days and 3 months after pancreatectomy, respectively. The 80% pancreatectomy was performed following the procedure reported by Bates and Garrison (1967).A third series of 20 intact male and 25 intact female rats was used as control. Another series consisting of 5 controls and 5 80 %-P~rats was studied at mid-day by the Oral Glucose Test (200 mg/100 g, 40% glucose solution).The post-stress glycemia-glycosuria response was classified as: a) hyperglycemic response when glycemia was between 150 and 179 mg%, without glycosuria; b) diabetic response when glycemia rose over 180 mg% accompanied by glycosuria, and came back to normal values within 4 hours; c) transient diabetes when the diabetic response lasted 8 hours or more, but returned to normal levels, and d) permanent diabetes when the diabetic response was irreversible.

Stress and Diabetes Mellitus

“…Animals that were partially pancreatectomized surgically have been shown to develop either transient or permanent diabetes after restraint stress (13). Although these animals do not develop diabetes spontaneously, restraint stress produced transient or permanent diabetes in 25-28% of pancreatectomized animals, but none of the control animals developed diabetes.…”

Major developments in behavioral diabetes research.

“…Studies with animal models, using surgically or chemically induced diabetes or strains of mice and rats genetically predisposed to IDDM, have yielded contradictory results. Although some researchers have found that stress accelerates IDDM onset (Capponi, Kawada, Verela, & Vargas, 1980; Carter, Herrman, Stokes, & Cox, 1987), others have found that stress inhibits IDDM onset (Ader, Johnson, Huang, & Riley, in press; Huang, Plaut, Taylor, & Wareheim, 1981).…”

Effect of Chronic Noise Stress on Serum Glucose and Lipids and Morphology of Langerhans Islets in Neonatal Rats

“…In humans, several studies have shown that stress may induce type 1 diabetes mellitus [5,6]. Animal studies have also shown that different kinds of stressors may induce or inhibit type 1 diabetes in different experimental models of the disease [7]. Noise pollution is one of the harmful environmental factors for humans when it is higher than normal, could adversely affects to health [8,9].…”