Strict insulin therapy normalises organ nitrogen contents and the capacity of urea nitrogen synthesis in experimental diabetes in rats

Abstract

Rats with experimental diabetes due to streptozotocin (75 mg/kg body weight) and free access to food were divided into two groups. One group (n = 9) was optimally treated with insulin (glucosuria less than 4.0 mmol/24 h), using heat treated very long-acting ultralente insulin. The other group (n = 10) was poorly treated with insulin (glucosuria 20-30 mmol/24 h). The nitrogen balance and energy balance of optimally treated diabetic rats was positive and not different from the control group (n = 6). In the poorly treated diabetic rats the nitrogen balance was reduced whereas the energy balance was not different from that of control rats. After 4 weeks the fasting glucagon was: 50 +/- 21 ng/l (mean +/- SEM) in control rats, 62 +/- 18 ng/l in optimally treated diabetic rats and 249 +/- 58 ng/l in poorly treated diabetic rats (p less than 0.01). The capacity of urea nitrogen synthesis determined during alanine loading was: 9.6 +/- 1.0 mumol/(min 100 g body weight) in control rats, 10.6 +/- 1.7 mumol/(min 100 g body weight) in optimally treated diabetic rats and 17.3 +/- 1.3 mumol/(min 100 g body weight) in poorly treated diabetic rats (p less than 0.01). Nitrogen contents of carcass, heart, intestines, liver, and kidneys as determined by Kjeldahl analyses were identical in control rats and optimally treated diabetic rats.(ABSTRACT TRUNCATED AT 250 WORDS)