Diabetes, Vol 34, Issue 1 22-28, Copyright © 1985 by American Diabetes Association
Urinary and renal tissue kallikrein in the streptozocin-diabetic rat
RK Mayfield, HS Margolius, GS Bailey, DH Miller, DA Sens, J Squires and DH Namm
The renal kallikrein-kinin system is thought to participate in blood
pressure regulation and displays abnormalities in human hypertension, as
well as in many animal models of hypertension. Urinary excretion and tissue
levels of renal kallikrein were measured in streptozocin (STZ)-diabetic
rats in relation to blood pressure, glycemia, and insulin treatment. In
study 1, STZ-diabetic rats with marked hyperglycemia showed reduced
kallikrein-like esterase excretion, compared with control rats, when first
measured after 7 days of diabetes (9.9 +/- 2.5 versus 17.5 +/- 2.4 EU/24 h,
P less than 0.05). This difference increased with time and, after 210 days,
urinary esterase excretion in diabetic and control rats was 6.7 +/- 2.1 and
39.0 +/- 6.0 EU/24 h, respectively (P less than 0.001). Urine kallikrein,
measured by radioimmunoassay, was similarly reduced in diabetic rats (40.4
+/- 8.0 versus 88.0 +/- 6.5 micrograms/24 h, at 30 days, P less than
0.001). At 120 days, systolic blood pressures were elevated in diabetic
rats (P less than 0.05), and at 180 days over 60% of the diabetic rats had
pressures above the highest pressures of control rats. In study 2,
STZ-diabetic rats were treated with insulin for 2 wk (2 U NPH at 0800 h, or
2 U NPH at 0800 and 1600 h). In the single-dose group, with hyperglycemia
similar to that of diabetic rats in study 1, kallikrein excretion was
reduced as early as day 2, compared with nondiabetic rats (56.0 +/- 6.1
versus 109 +/- 9.4 micrograms/24 h, respectively, P less than
0.001).(ABSTRACT TRUNCATED AT 250 WORDS)