Hepatic Estrogen Sulfotransferase Distantly Sensitizes Mice to Hemorrhagic Shock-Induced Acute Lung Injury.

Hemorrhagic shock (HS) is a potential life-threatening condition that may lead to injury to multiple organs, including the lung. The estrogen sulfotransferase (EST, or SULT1E1) is a conjugating enzyme that sulfonates and deactivates estrogens. In this report, we showed that the expression of Est was markedly induced in the liver but not in the lung of female mice subject to HS and resuscitation. Genetic ablation or pharmacological inhibition of Est effectively protected female mice from HS-induced acute lung injury (ALI), including interstitial edema, neutrophil mobilization and infiltration, and inflammation. The pulmonoprotective effect of Est ablation or inhibition was sex-specific, because the HS-induced ALI was not affected in male Est-/- mice. Mechanistically, the pulmonoprotective phenotype in female Est-/- mice was accompanied by increased lung and circulating levels of estrogens, attenuated pulmonary inflammation, and inhibition of neutrophil mobilization from the bone marrow and neutrophil infiltration to the lung, whereas the pulmonoprotective effect was abolished upon ovariectomy, suggesting that the protection was estrogen dependent. The pulmonoprotective effect of Est ablation was also tissue specific, as loss of Est had little effect on HS-induced liver injury. Moreover, transgenic reconstitution of human EST in the liver of global Est-/- mice abolished the pulmonoprotective effect, suggesting that it is the EST in the liver that sensitizes mice to HS-induced ALI. Taken together, our results revealed a sex- and tissue-specific role of EST in HS-induced ALI. Pharmacological inhibition of EST may represent an effective approach to manage HS-induced ALI.

A sensitive and robust UPLC-MS/MS method for quantitation of estrogens and progestogens in human serum.

OBJECTIVE: With the widespread use of sex-steroid hormones in contraceptives and hormone replacement therapy, there is an increasing need for reliable analytical methods. We report the development of a sensitive and robust UPLC-MS/MS method for quantitation of both endogenous and synthetic sex-steroid hormones in human serum. STUDY DESIGN: We developed and validated a UPLC-MS/MS method to quantify progestogens (etonogestrel, levonorgestrel, medroxyprogesterone acetate, norethindrone, progesterone) and estrogens (estradiol and ethinyl estradiol) with good accuracy, high sensitivity, and excellent robustness. We then applied the method to the analysis of sex-steroid hormones in serum from 451 clinical research participants. RESULTS: Each UPLC-MS/MS analysis was 6.5 min. The lower limits of quantitation (LLOQs) were 25 pg/ml for the progestogens, and 2.5 and 5.0 pg/ml for estradiol and ethinyl estradiol, respectively. When estradiol was analyzed without assessment of progestogens, the LLOQ was reduced to 1 pg/ml. The calibration curves were linear from 25-50,000, 2.5-2000 (1-2000 for estrogens-only analysis) and 5-2000 pg/ml, respectively. Both the accuracy and precision were below±15% not only for routine validation (intraday and interday), but for long-term (>2 years) assay robustness with external controls, thereby, demonstrating the utility of this method for multi-year clinical trial assessments of progestogens and estrogens. We applied the method to quantify sex-steroid levels in 1804 clinical samples. CONCLUSIONS: We successfully developed a UPLC-MS/MS method, and overcame the matrix suppression to allow sensitive quantitation of both synthetic and endogenous sex-steroid hormones in human serum. IMPLICATIONS: We developed a sensitive and robust UPLC-MS/MS method to accurately measure the levels of sex-steroid hormones in serum. The method overcame matrix interference barriers and achieved excellent long-term stability and reproducibility (≥96.9% accuracy; ≤13.0% relative variability measured with external controls over 2 years), demonstrating its utility in clinical sample analysis.

Adenosine Administration With a Stopcock Technique Delivers Lower-Than-Intended Drug Doses.

STUDY OBJECTIVE: Adenosine administration with a stopcock is the recommended treatment for pediatric patients with acute supraventricular tachycardia. Recent reports suggest that many infants do not respond to the first dose of adenosine administered. Our aim is to determine whether administration of adenosine with a stopcock delivers lower-than-expected drug doses in patients weighing less than 10 kg, corresponding to weights of infants. METHODS: We developed an in vitro model of adenosine delivery. Doses of adenosine corresponding to weights 2 to 25 kg were calculated, using a dose of 0.1 mg/kg, and administered through one port of a stopcock. Distilled water was administered through the second port. The adenosine concentration of the output was measured with mass spectrometry and results were confirmed with spectrophotometry of Evans blue. RESULTS: The mean doses of adenosine delivered through the stopcock increased as weight increased. The mean dose of adenosine delivered was 0.08 mg/kg for weights 2 to 9 kg and 0.1 mg/kg for weights 10 to 25 kg (95% confidence interval for difference of means -0.03 to -0.009). The median dose of adenosine delivered was 0.07 mg/kg (interquartile range [IQR] 0.06 to 0.07 mg/kg), 0.09 mg/kg (IQR 0.08 to 0.09 mg/kg), and 0.1 mg/kg (IQR 0.09 to 0.1 mg/kg) for weights 2 to 5, 6 to 9, and 10 to 25 kg, respectively (rank difference=100; P<.05 for 2 to 5 kg versus 10 to 25 kg). Similar results were obtained with spectrophotometry. CONCLUSION: Administration of adenosine through a stopcock delivers doses lower than intended in patients weighing less than 10 kg, which may account for the decreased response of infants to the first dose of adenosine.