The following is an abstract of the article discussed in the subsequent letter:

Marshall, Sally M., Klavs W. Hansen, Ruth Østerby, Jan Frystyk, Hans Ørskov, and Allan Flyvbjerg. Effects of heparin on renal morphology and albuminuria in experimental diabetes. Am. J. Physiol. 271 (Endocrinol. Metab. 34): E326-E332, 1996.Female nondiabetic and streptozotocin diabetic Wistar rats received 200 units heparin two times daily by subcutaneous injection for 6 mo. Mesangial volume fraction was reduced in heparin-treated control (CH) compared with untreated control (C) animals (CH 0.18 ± 0.02 vs. C 0.24 ± 0.02, P < 0.05), but other histological parameters were similar. In the heparin-treated diabetic (DH) group, wet kidney weight was increased compared with the untreated diabetic (D) group (DH 1,156 ± 39 vs. D 1,050 ± 30 mg, P < 0.05), as were absolute, but not fractional, glomerular volume (P < 0.05) and capillary volume (P < 0.05). Basement membrane thickness (DH 193 ± 3 vs. D 231 ± 9 nm, P < 0.01) and mesangial/glomerular volume fraction (P < 0.001) were decreased. Urinary albumin excretion was increased in the heparin-treated control animals compared with control animals [CH 980 (range 150-4,446) vs. C 221 (range 86-654) µg/24 h, P < 0.001] and in the heparin-treated diabetic animals compared with the diabetic animals [DH 12,785 (range 4,495-29,520) vs. D 899 (range 450-1,335) µg/24 h, P < 0.001]. Thus the possibly deleterious increases in glomerular capillary volume and albumin excretion may negate the beneficial effects of heparin on mesangial and basement membrane structures.