Studies on the a-Glucosidase Specific for Collagen Disaccharide Units: Variations Associated with Capillary Basement Membrane Thickening in Kidney and Brain of Diabetic and Aged Rats

Inhibition of the ?-glucosidase specific for collagen disaccharide units in diabetic rat kidney by in vivo glucose levels: possible contribution to basement membrane thickening

“…In the previous experiments, thickening of kidney glomerular basement membrane was confirmed after 28 weeks of diabetes [2]. The increase in kidney weight observed here, as previously [2], is moderate compared with other published data [11]. The greater severity of the diabetes in our experiments, as reflected by the plasma glucose levels, could account for this.…”

“…The increase in glucosyl-galactosyl-hydroxylysine glucohydrolase activity in the dialyzed rat kidney cortex previously reported after 19, 23 and 28 weeks of diabetes [2] is again confirmed by the measurement of elevated activities after 33 weeks of diabetes induced under similar conditions. In the previous experiments, thickening of kidney glomerular basement membrane was confirmed after 28 weeks of diabetes [2]. The increase in kidney weight observed here, as previously [2], is moderate compared with other published data [11].…”

“…With long-term streptozotocin diabetic rats, we have observed previously an increased activity of the a-glucosidase specific for collagen disaccharide units (glucosylgalactosyl-hydroxylysine glucohydrolase) in the dialyzed kidney cortex homogenate and supematant [1,2]. In the same animals, we have confirmed the presence of kidney glomerular basement thickening [2].…”

“…Summary. The activity of the a-glucosidase specific for collagen disaccharide units has been measured in kidney cortex homogenates of streptozotocin-diabetic rats under three different conditions: (1) in dialyzed homogenates; (2) in non-dialyzed homogenates; (3) in non-dialyzed homogenates to which glucose was added to compensate for dilution due to homogenization and to reach the glucose concentration determined in kidney cortex (37.5 +2.8 mmol/kg diabetic cortex versus 6.8___0.3 mmol/kg normal cortex). Under the latter condition, the enzyme activity was markedly decreased in diabetic kidney cortex when compared with that of normal agematched controls: 4.03 + 0.25 versus 6.82_+ 0.29 units/rag pro-tein (p < 0.001).…”

Aging and Diabetes Increase the Aggregating Potency of Rat Skin Collagen Towards Normal Platelets

“…Values are expressed as mean + S. E. M.; {<* p <0.01. Maximum transmission percentages were 75.0 + 2.5"/" for the aged versus 70.0 + (18); for those of the diabetics and their controls, see (19). Tendon collagen was isolated according to Kang, see (8)…”