Evaluation on diagnostic value of leucine aminopeptidase in hyperthyroidism / 国际检验医学杂志

Objective To detect serum leucine aminopeptidase (LAP) level in the patients with hyperthyroidism for investiga‐ting the changes of LAP in the patients with thyroid dysfunction and its clinical significance .Methods 117 patients with hyperthy‐roidism were taken as the test group and 109 healthy people as the control group .The differences of various laboratory indexes were comparatively analyzed and the correlation between LAP with FT 3 ,FT4 and TSH was analyzed .117 patients with hyperthyroidism were divided into the liver damage group(52 cases) and non‐liver damage group(65 cases) and performed the LAP determination . Results The serum LAP ,FT3 ,FT4 and TSH levels in the hyperthyroidism whole group ,hyperthyroidism liver damage group and hyperthyroidism non‐liver damage group had statistically significant differences compared with those in the control group (P0 .05) .Conclusion The serum LAP content is closely related with the thyroid hormones and has certain clinical reference value for the diagnosis ,disease condition evaluation and medication .Lap can serve as an independent diagnostic indicator .

Placental Leucine Aminopeptidase/Oxytocinase Expression in Miscarriage.

Objectives: To evaluate the role of placental leucine aminopeptidase (P-LAP) in miscarriage and searching to select the gene of this enzyme in miscarriage to exclude direct or indirect effects of abortion. Methods: Total RNA is purified from the fresh placental tissue sample according to the protocol of the QIAamp®RNA Tissues Mini Kit (Qiagen). The sample is visualized by 0.7% agrose gel containing. Total RNA is reverse-transcribed RT-PCR carried out on the previously extracted RNA samples using (QIAGEN One Step RT –PCR Kit). Aliquots (1ml) of RT reaction samples are amplified by PCR, the PCR products (10μl) per lane are resolved by using electrophoresis on 2.0% agrose gel .Later the product is detected and examined under UV transiluminator. Results: The obtained results indicate that there is an expression of P-LAP mRNAs in placentas of normal pregnancy women (28±SE0.45) and there is a decrease in miscarriage. Furthermore, there is a difference between single miscarriage and those with recurrent miscarriage, the mean values in single miscarriage (1st and 2nd) are (16.1%±SE0.84) and (13%±SE0.24) respectively while the mean values in recurrent miscarriage (1st and 2nd) are (12%±SE0.19) and (9%±SE0.52) respectively. The expression of P-LAP is significantly lower (p=0.05) in miscarriage and highly significant decrease in recurrent than in single miscarriage women. Conclusion: The decrease of P-LAP mRNA levels in miscarriage placentas could be a sign that p-LAP function is an important step in pregnancy regulation.

Effect of gallic acid on alkaline phosphatase and peptidase activities in rat intestine.

Gallic acid is a normal constituent of many edible foods, thus directly interacts with epithelial tissue in intestine. In the present study, the effect of gallic acid on intestinal alkaline phosphatase (IAP) and peptidase activities in rat intestine was evaluated. Gallic acid (0.27-0.5 mM) inhibited activities of leucine aminopeptidase (LAP) and -glutamyl transpeptidase (-GTP) by over 90%, compared to controls in rat intestine. In contrast, 0.1-0.6 mM gallic acid either had no effect or stimulated the activity of IAP in rat intestine. The observed inhibition of peptidases by gallic acid was reversible in nature. Kinetic analysis revealed no change in Vmax of LAP (0.42-0.44 units/mg protein) and -GTP (0.22-0.24 units/mg protein), while the values of apparent Km were increased 6-7 fold, exhibiting competitive-type of enzyme inhibition by gallic acid. The values of Ki for LAP and -GTP were 0.037 mM and 0.017 mM, respectively. These observations indicate that gallic acid is a potent inhibitor of brush border peptidases, and thus may interfere in the digestion and absorption of proteins in the intestine.

Clinical significance of diversity of serum LAP during pregnancy / 临床检验杂志

Objective To explain the physiological properties of serum leucine aminopeptidase (LAP) and discuss the different levels and clinical meaning of serum LAP during the second and the third trimester of gestation.Methods Rate turbidimetry was used to assay serum LAP activity of 175 pregnant women in the second trimester of gestation, among whom 162 were normal and 13 were intrahepatic cholestasis of pregnancy (ICP), and 302 pregnant women in the third trimester of gestation, among whom 215 were normal, 76 were ICP, 6 were pregnancy-induced hypertension syndrome and 5 were premature delivery, and 100 healthy or non-pregnant women.Results Serum LAP activity of pregnant women in the group of the second trimester of gestation was (140.43?64.39) U/L, in the group of the third trimester of the gestation was (234.72?93.53) U/L, and in control group was (72.62?15.31) U/L. The serum LAP activities of the two pregnant groups were much higher than that of control group (P