In order to investigate the effect of high blood glucose levels of long duration on carbonic anhydrase, and to evaluate the relation of the enzyme to its inhibitors in uncontrolled Type 1 diabetic ...patients, erythrocyte CA -I and CA-II activities and their kinetic parameters were determined. The effects of glycation on erythrocyte carbonic anhydrase-I and II (CA-I and CA-II) in patients with Type-I diabetes mellitus (uncontrolled) were investigated using kinetic parameters. After blood glucose and hemolysate total esterase activity levels had been measured in both 10 control and 10 diabetic subjects, CA-I and CA-II in hemolysate were purified separately by affinity chromatography. The enzyme activity, fructosamines, V max , K M , and K i values of CA-I and CA-II were determined. The means of the blood glucose and hemolysate total esterase activity levels were significantly higher in the diabetics than in the controls ( p < 0.001). After purification, the means of the enzyme activity, fructosamines, and V max values of both CA-I and CA-II were significantly higher in the diabetics than in the controls ( p < 0.01 p < 0.001 and p < 0.01) respectively, while the K M values exhibited no significant differences ( p > 0.05). The means of the K i values of both CA-I and CA-II, using acetazolamide and sulfanilamide inhibitors, were significantly lower in the diabetics than in the controls ( p< 0.001). Glycation was found to increase both CA activity and the inhibitory effect of acetazolamide and sulfonamide on CA activity. Since CA is a well-known enzyme regulating pH in most of the tissues in the body, changes in CA activity may be associated with metabolic diseases, especially in diabetes mellitus. Therefore, dosages of CA inhibitors should be considered carefully in the treatment of diabetic patients.
To investigate the effects of aminoguanidine cream on the proliferation of keratinocytes (KC), content of advanced glycosylation end products (AGE) and oxidative stress in skin tissue of rats with ...diabetes.
Stearic acid, liquid paraffin, vaseline, lanolin, isopropyl myristate fat, glycerol, 50 g/L alcohol paraben, aminoguanidine hydrochloride etc. were mixed in certain proportion to make aminoguanidine cream, and cream without aminoguanidine was used as matrix. The dorsal skin of normal rats were harvested and treated by aminoguanidine cream with dose of 5, 10 g/L, or 5 g/L together with 10 g/L azone. The transdermal effect was respectively measured at post treatment hour 2, 4, 7, 10, 12, 24. Thirty SD rats were divided into normal control (NC, n = 6), diabetes (D, n = 8), aminoguanidine cream-interfered (AI, n = 8), matrix cream-interfered groups (MI, n = 8) according to the random number table. Diabetes was reproduced by intraperitoneal injection of STZ (65 mg/kg) in rats of D, AI, and MI groups, and rats i
Advanced glycation end products (AGEs) formation is implicated in diabetic complications. Exogenous AGEs, namely glycotoxins, are present in certain foods and are absorbed from the gastrointestinal ...tract. Experimental data suggest that lifestyle interventions reducing their content in diet have beneficial effect.
Fourteen healthy (age: 42.14 +/- 12.38 years; body mass index BMI: 27.85 +/- 7.06 kg/m2) and ten women with type 2 diabetes (T2DM) (age: 48.70 +/- 9.31 years; BMI: 32.55 +/- 7.14 kg/m2) were enrolled in the study. A meal rich in AGEs was provided in a two-day protocol and on day 2, 240 mg of Orlistat were administered post-meal.
On day 1, serum AGEs levels showed a rise at 3 hours post-meal compared to baseline values in both groups (controls: 12.2%; P<0.001), T2DM: 2.6%; P=0.013), but at 5 hours post-meal only in the controls (control: 12.2%; P<0.001); T2DM: 1.9%; P=0.075). On day 2 at 3 hours post-meal control values showed a rise of 3.1% (P=0.003); T2DM of 1.9% (P=0.013); at 5 hours post-meal rise for controls was 4.6% (P=0.012); and for T2DM was 1.8% (P=0.009). The corresponding rise was significantly lower on day 2 only in controls at 3 and 5 hours post-meal (P=0.003; P=0.05, respectively).
Orlistat reduced the absorption of glycotoxins acutely and improved the metabolic profile in the control group, without an apparent beneficial effect in the diabetic group. The clinical significance of this observation should be further investigated in normal population, while in diabetics long-term studies may be required to demonstrate possible clinically significant effects.
To investigate the effects of advanced glycation end products (AGE) on the biological behavior of neutrophils in vitro, to look for the relationship between accumulation of AGE and abnormal ...inflammation in wound healing in diabetic mellitus patients.
Neutrophils were isolated from SD rats and incubated in vitro. The cells were divided into four groups according to different concentrations of AGE in cell suspension: control group (C, with treatment of RPMI - 1640), A group (with treatment of 0.315 mg/mL AGE + RPMI - 1640), B group (with treatment of 0.625 mg/mL AGE + RPMI - 1640), D group (with treatment of 1.250 mg/mL AGE + RPMI - 1640). Activity of neutrophils were determined by MTT colorimetric assay. Selectin-L mRNA expressions were analyzed by reversible transcription polymerase chain reaction (RT -PCR) technique. The levels of reactive oxygen species (ROS) in neutrophils were measured with DCFH-DA method. The protein concentration of neutrophil elastase (NE) was assayed by ELISA.
The activity of neutroph
To investigate the effect of advanced glycosylation end products (AGE) on cell cycle of epidermal keratinocyte and its possible signal pathway.
150 mg/L AGE-human serum albumin (AGE-HSA) was prepared ...in vitro. Primary cultured keratinocytes in logarithmic growth phase were harvested and divided randomly into: A group with treatment of defined keratinocyte-SFM (DK-SFM) serum-free medium, B group (with treatment of DK-SFM medium including 150 mg/L AGE-HSA), C group (with DK-SFM medium after treatment of U0126) and group D (with D K-SFM medium including 150 mg/L AGE-HSA after treatment of U0126). Cell cycle distributions were analyzed by flow cytometer. The protein levels of cyclin D1, cyclin B1, CDK4 and p44/42 MAPK were measured by Western blot.
Compared with those of A group, the percentage of S-phase and G2/M-phase keratinocytes were decreased obviously in B group, the percentages of G2/M -phase keratinocytes showed the same tendency in C and D groups (9.7 +/- 1.1)% , (9.8 +/- 0.7)%, respectively, P <0.05
