OBJECTIVETo establish a gas chromatography method for determination of methyl propyl ketone in the air of workplace.

METHODSMethyl propyl ketone in the air of workplace was collected with activated carbon tubes and desorbed with carbon disulfide before sample loading. The target toxicant was separated with the capillary column and detected with a hydrogen flame ionization detector, identified by retention time, and quantified by peak area.

RESULTSThe linear range of methyl propyl ketone in the air of workplace was 202.5∼4 860.0 µg/ml, with a correlation coefficient of 0.999 98. The limit of detection was 1.5 µg/ml. The lower limit of quantification was 5.0 µg/ml. The minimum detectable concentration was 1.0 mg/m(3) under 1.5 L sampling volume and 1.0 ml desorption solution volume. The relative standard deviation of different methyl propyl ketone concentrations was 1.42%∼1.65%, and the recovery rate was 94.9%∼ 97.9%.

CONCLUSIONThis method has high sensitivity, precision, and accuracy, and it is applicable for determination of methyl propyl ketone in the air of workplace.

Air ; analysis ; Air Pollutants, Occupational ; analysis ; Carbon Disulfide ; Chromatography, Gas ; methods ; Pentanones ; analysis ; Workplace

The effects of carvedilol on cardiomyocyte apoptosis and expression of bcl-2, bax genes following ischemia (0.5 h) and reperfusion (48 h) in vivo and the possible biological mechanism of carvedilol inhibiting cardiomyocyte apoptosis were studied. The left anterior descending artery in Wistar rats were ligated to establish ischemia-reperfusion (I/R) models. The model animals were divided into two groups: I/R group, the model rats not subject to other treatments except ischemia-reperfusion (n = 8); carvedilol-treated group (n = 8), I/R model rats treated with carvedilol. Eight rats in the sham-operated group were subjected to only experimental open operation. The number of apoptotic cardiomyocyte was determined by TUNEL staining. Immunohistochemistry and in situ hybridization histochemistry (ISHH) were used to detect the expression of bcl-2 and bax genes. Image processing system was used to quantitatively dispose the positive metric substances of both immunohistochemistry and ISHH through the average optical density (OD) value. The results showed that the number of the apoptotic cells were 36.18 +/- 9 (I/R group), 0-1 (sham-operated group) and 9.5 +/- 3 (carvedilol-treated group) in each visual field respectively with the difference being very significant among the groups (P < 0.001). The OD values of bcl-2 protein in sham-operated group, I/R group and carvedilol-treated group were 0.14 +/- 0.01, 0.08 +/- 0.02 and 0.15 +/- 0.03, respectively. The OD values of bcl-2 mRNA in sham-operated group, I/R group and carvedilol-treated group were 0.08 +/- 0.01, 0.06 +/- 0.01 and 0.09 +/- 0.01, respectively. There was no significant difference between carvedilol-treated group and I/R group (P > 0.05). The OD values of bax protein in I/R group, sham-operated and carvedilol-treated-treated group were 0.13 +/- 0.02, 0.07 +/- 0.01, 0.06 +/- 0.01, respectively. There was very significant difference between carvedilol-treated group and I/R group (P < 0.01). Bcl-2/bax ratio was 1.07 +/- 0.14 (I/R group), 1.28 +/- 0.16 (sham-operated group), 2.5 +/- 0.26 (carvedilol-treated group) respectively with the difference being very significant between carvedilol-treated group and I/R group (P < 0.05). It was indicated that carvedilol could inhibit cardiomyocyte apoptosis following ischemia and reperfusion, which was related to the increased bcl-2/bax ratio due to inhibition of bax gene expression.
Adrenergic alpha-Antagonists ; pharmacology ; Adrenergic beta-Antagonists ; pharmacology ; Animals ; Apoptosis ; drug effects ; Carbazoles ; pharmacology ; Gene Expression ; Myocardial Ischemia ; genetics ; pathology ; Myocardial Reperfusion Injury ; genetics ; pathology ; Myocytes, Cardiac ; pathology ; Propanolamines ; pharmacology ; Proto-Oncogene Proteins ; metabolism ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Random Allocation ; Rats ; Rats, Wistar ; bcl-2-Associated X Protein

OBJECTIVETo study the relationship between tissue quantitative distribution and pharmacokinetics of 3H-achyranthes bidentata ecdysterone and the channel-tropism of herbal drugs in mice.

METHOD3H-achyranthes bidentata ecdysterone was used as a tracer agent and injected into mice by the caudal vein. In 36 hours, the contents of the tracer agent of samples involving 9 different tracing phases and organ or tissue were determined in order to observe the dynamic quantitative distribution and excretion and pharmacokinetics of 3H-achyranthes bidentata ecdysterone and to understand the channel-tropism of herbal drugs achyranthes bidentata.

RESULT3H-achyranthes bidentata ecdysterone of same organs in different tracing phases and the contents of 3H-achyranthes bidentata ecdysterone in same tracing phases of different organs were significantly different (P<0.01). 3H-achyranthes bidentata ecdysterone was mainly distributed, in the liver, kidney, adrenal gland, small intestine and lung. The concentration-time profiles of achyranthes bidentata ecdysterone in rats injected into mice by the caudal vein were shown to fit a two-compartment open model with half-lives of (778.65 +/- 12.36) min, the elimination of achyranthes bidentata ecdysterone from plasma was found to be in accord with linear kinetics.

CONCLUSIONThe above mentioned selective distribution of 3H-achyranthes bidentata ecdysterone basically coincides with the meridian affinity and zang fu selection of the traditional Chinese medicine drug Achyranthes bidentata. This study will provide a scientific basis for the channel-tropism of A. bidentata.

Achyranthes ; chemistry ; Animals ; Drugs, Chinese Herbal ; metabolism ; pharmacokinetics ; Ecdysterone ; metabolism ; pharmacokinetics ; Isotope Labeling ; Male ; Meridians ; Mice ; Organ Specificity ; Tissue Distribution ; Tritium ; chemistry