ABSTRACT
Objective:To study the pharmacokinetics,thissue distribution and secretion of nerve growth factor(NGF)in mice.Methods:The conecntration of NGF in various body fluids and tissue were determined by isotope tracer combined SDSPAGE method.Results:The plasma concenmtration-time curve was in accordance with the two-compartment pharmacokinetic model.The elimation half-life(t1/2β)was 3.1.The half-life of distribution(t1/2ka)was 5min.Tpeak was 25 min.AUC was 72.4 mg·kg-1·h-1.The concentrations of NGF were high in thyroid,blood,submaxillary glands,superior cervical ganglion,adrenasl and kidneys.Conclusion:NGF has a wide distribution,high tissue concentrationa nd excrtet mainly through the urine.
ABSTRACT
Objective:To investigate the inhibitory effect of Epibueropyridinium A on aldose reductase.Methods: Aldose reductase was extracted from cattle crystalline lens.Besides Epibueropyridinium A,the reactive system also contained DL-glyceraldehyde,aldose reductase,and NADPH.The activity changes of aldose reductase were detected at 340 nm.Epalrestat was taken as the positive control.The inhibitory type,Ki and IC_(50) were determined by double reciprocal plot,quadratic drawing,and drawing of inhibitor's concentration to inhibitory ratio,respectively.Results: Epibueropyridinium A significantly inhibited the activity of aldose reductase in a competitive manner,with IC_(50) being 4.2 ?g/ml and Ki being 4.88 ?g/ml.Conclusion: Epibueropyridinium A is competitive inhibitor of aldose reductase.
ABSTRACT
The effect of plasma middle molecule substances (MMS) on the Ca2+-ATPase activity in human erythrocyte membranes was studied. The results showed that the Ca2+-ATPase activity was significantly inhibited when the membrane preparation was incubated with MMS at 37℃. The longer the period of time for incubation, the lower the Ca2+-ATPase activity. The activity of Ca2+-ATPase could be significantly inhibited by plasma MMS of both normal person and burn patient. The inhibitory rate (%) of Ca2+-ATPase activity was elevated markedly when MMS concentration was increased (P