Glomerular charge selectivity in type 1 (insulin-dependent) diabetes mellitus.
Glomerular charge selectivity was assessed using the ratio of the clearance of pancreatic isoamylase to the clearance of the more anionic salivary isoamylase (CPAm/CSAm) in 12 normal subjects and 50 patients with Type 1 diabetes: 13 with normal albumin excretion and short duration of diabetes (< 5 years), 15 with normal albumin excretion and long duration of diabetes (> 15 years), 13 with microalbuminuria, and 9 with clinical nephropathy. None had serum creatinine > 200 mumol l-1. There were no significant differences in CPAm/CSAm between the normal subjects and the two groups of normoalbuminuric patients with Type 1 diabetes. CPAm/CSAm was significantly lower in diabetic patients with microalbuminuria or clinical nephropathy than in normoalbuminuric patients with Type 1 diabetes. When the 37 patients with normoalbuminuria and long-standing diabetes, microalbuminuria, and nephropathy were considered together, there was a significant negative correlation between CPAm/CSAm and albumin excretion rate (rs = 0.71, p < 0.001). Progressive impairment of glomerular charge selectivity at the molecular size of amylase (molecular mass 56 kDa) accompanies increasing albuminuria in Type 1 diabetes.
Fox
J G
JG
Renal Unit, Royal Infirmary, Glasgow, UK.
Quin
J D
JD
Paterson
K R
KR
O'Reilly
D S
DS
Smith
M P
MP
Boulton-Jones
J M
JM
D000328:Adult; D000419:Albuminuria / Q000209:etiology / Q000378:metabolism; D016022:Case-Control Studies; D003404:Creatinine / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000150:complications / Q000378:metabolism*; D003928:Diabetic Nephropathies / Q000378:metabolism*; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism; D007517:Isoamylase / Q000378:metabolism; D007678:Kidney Glomerulus / Q000378:metabolism*; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D010179:Pancreas / Q000201:enzymology; D012463:Saliva / Q000201:enzymology
D007074:Immunoglobulin G; D003404:Creatinine; D007517:Isoamylase