Evaluation of Minimum Reporting Limits to Determine In-Competition Use of Stimulants.

The applicability of urinary minimum reporting limits (MRLs) to determine in-competition use of prohibited substances is an evolving topic. Most stimulants are subject to a universal MRL, despite the wide range of commercially available dosages for commonly used stimulants. Further, it is unknown whether the urinary MRL is reflective of a pharmacological dose ingested after the start of the in-competition period. To evaluate whether urinary MRLs can distinguish between in-competition and out-of-competition use, a controlled administration study was performed with three commonly used stimulants-amphetamine, methylphenidate, and modafinil at relatively low but therapeutically relevant dosages. Four to six volunteers were administered a particular drug once per day for five consecutive days. Urine, serum, dried blood spots (DBS), and oral fluid (OF) were collected during the active administration period and for 48 h after cessation of use. For all participants, urinary concentrations for all target analytes exceeded the MRL even 48 h after cessation of use. In serum and DBS, most volunteers showed detectable amounts at 48 h post use. Peak concentrations were variable between target compounds even with similar administered dosages. Further, there was a reproducible difference between serum and DBS concentrations. Interpretation of results from OF measurements was challenging due to the inability to normalize for hydration status and OF viscosity. Analyte concentrations decreased steadily over the washout period but did not correlate across matrices for all target analytes. The study reiterates the challenges associated with determining in-competition use by relying on urinary concentrations.

Is blood blood? Comparing quantitation of endogenous steroids and luteinizing hormone in concurrently collected venous serum and Tasso+ SST capillary serum samples.

The monitoring of endogenous steroids in urine has been an important component of the Athlete Biological Passport (ABP) for the last decade. Recently, the quantitation of endogenous steroids in blood has been incorporated into the ABP to increase sensitivity in circumstances where the excretion of urinary ABP biomarkers is low. Current ABP guidelines mandate the use of venous blood draws for blood steroid sample collections, however, recent efforts have focused on investigating the use of less invasive sample collection methods, such as capillary blood collected from the upper arm. The focus of this study was to compare the analytical results of venous and capillary blood collected weekly from 20 individuals, 10 males and 10 females, over six weeks. The two primary biomarkers of the blood steroid ABP module, testosterone (T) and the testosterone/androstenedione (T/A4) ratio, were compared, as well as luteinizing hormone (LH) and the T/LH ratio in male participants, two biomarkers known to be responsive to T use. All biomarkers showed excellent agreement between venous and capillary blood. Longitudinal stability between sample types within individuals was also comparable for all biomarkers. Finally, storage of simultaneously collected capillary samples at room temperature and frozen conditions was compared with evaluate the potential impact of non-cold chain shipping conditions. Most biomarkers showed excellent agreement between frozen and room temperature storage conditions. These results indicate capillary blood collections represent a promising alternative to venous blood collections for the blood steroid module of the ABP.

Influence of multiple human chorionic gonadotropin administrations on serum and urinary steroid Athlete Biological Passport profiles in males.

The Athlete Biological Passport (ABP) is a longitudinal tool used in anti-doping to monitor biological parameters known to change with performance-enhancing drug use. The ABP consists of multiple modules, including two aimed at detecting the use of endogenous anabolic androgenic steroids: the urinary and serum steroid modules. Human chorionic gonadotropin (hCG) is a protein hormone potentially abused by male athletes to increase the production of endogenous testosterone. To date, no studies have investigated the impact of extended hCG administration on the urinary and serum steroid modules of the ABP. The goal of this study was to identify the impact of multiple hCG administrations on the parameters tracked as part of the urinary and serum steroid modules of the ABP. Ten recreationally active, healthy male individuals self-administered seven 250 µg hCG injections over 3 weeks. Serum and urine samples were collected before, during, and 2 weeks following the final injection. All ABP parameters were quantified in the respective matrix, and steroid profiles were created with Anti-Doping Administration and Management System adaptive model upper and lower limits for both matrices. In both serum and urine profiles, testosterone increased; however, the testosterone/epitestosterone ratio in urine and the testosterone/androstenedione ratio in serum showed minimal changes. Additionally, serum luteinizing hormone (LH) was quantified using an immunoassay, and a serum testosterone/LH ratio was generated. Serum LH values decreased during administration causing large increases in the serum T/LH ratio, indicating this ratio may be a more sensitive parameter for detecting hCG abuse than urinary testosterone/epitestosterone or serum testosterone/androstenedione.

Impact of Biotin Supplementation on Human Chorionic Gonadotropin Immunoassays Utilizing Biotin-Streptavidin Binding Methods in Urine.

BACKGROUND: Human chorionic gonadotropin (hCG) detection is indicative of pregnancy and can be indicative of some forms of cancerous tumors. The hCG drug itself, however, is a performance enhancing substance used by male athletes to increase testosterone production. Antidoping testing for hCG is conducted in urine, often on immunoanalyzer platforms, many of which utilize biotin-streptavidin dependent immunoassays in which the presence of biotin in samples is a known confounding factor. While biotin interference in serum has been well-studied, the extent of biotin interference in urine has not. METHODS: Ten active male individuals underwent a 2-week hCG administration protocol concurrent with supplementation with biotin (20 mg/day) or placebo. Urine and serum samples were collected throughout the study and analyzed for hCG and biotin concentrations. RESULTS: Urinary biotin levels in the hCG + biotin group increased 500-fold over baseline and 29-fold over corresponding serum biotin levels after biotin supplementation. When using a biotin-dependent immunoassay, the hCG + placebo group produced hCG-positive results (hCG ≥ 5 mIU/mL) in 71% of urine samples, while the hCG + biotin group produced positive results in only 19% of samples. Both groups had elevated hCG values in serum measurements by a biotin-dependent immunoassay and in urine when using a biotin-independent immunoassay. Urinary hCG measurements and biotin levels from the hCG + biotin group showed a negative correlation (Spearman r = -0.46, P < 0.0001) when measured using a biotin-dependent immunoassay. CONCLUSIONS: Biotin supplementation can severely suppress urinary hCG values in assays utilizing biotin-streptavidin binding methods and therefore these types of assays are not recommended for use in urine samples containing high levels of biotin. Clinicaltrials.gov Registration Number: NCT05450900.

Simulation in Nurse Anesthesia Educational Programs: A Report by the AANA Simulation Subcommittee.

Simulation is an integral part of the healthcare educational landscape and a key element in the future of graduate professional education. For the past three decades, simulation-based educational methodology has been gaining popularity in nurse anesthesia educational programs (NAEP). There is currently limited objective evidence documenting modalities used or educational outcomes addressed through simulation in NAEPs. In 2018, the American Association of Nurse Anesthesiology (AANA) established a Simulation Subcommittee of the AANA Education Committee and tasked the group with two primary goals: 1) to gain a better understanding of the current state of simulation education and 2) to review responses with regard to how NAEPs could best incorporate simulation elements within their curriculum to meet requirements while adhering to the guidelines of the Council on Accreditation of Nurse Anesthesia Educational Programs. A survey tool was developed and distributed to all programs to assess the utilization of simulation, available simulation resources, ongoing faculty development efforts, and barriers to use of this educational approach. Survey results indicated that simulation is valued as an effective method within NAEPs for a variety of teaching and learning activities and is utilized to support achievement of both technical and nontechnical learning outcomes for student registered nurse anesthetists.

Opioid-Sparing Anesthesia: Gabapentin and Postoperative Pain.

PURPOSE: Nonopioid analgesics are commonly used to augment or replace opioids in the perioperative setting. Perianesthesia nurses must consider timing and appropriateness when administering these medications to patients in the preoperative area or the postanesthesia care unit, particularly when other medications with sedative effects are being given. Gabapentin, originally proposed as an anticonvulsant medication, promotes analgesia and reduces risk for postoperative nausea and vomiting. This review examines the effect of gabapentin on postoperative pain. DESIGN: A systematic review. METHODS: CINAHL, PubMed, and Cochrane Review databases were searched to find a total of 93 sources that examined gabapentin and postoperative pain. After applying inclusion and exclusion criteria, four randomized controlled trials (RCT) were reviewed. Postoperative pain within the 24 hours of surgery was measured as the primary outcome using the visual analog scale in all sources FINDINGS: Three of the four reviewed RCTs determined gabapentin was both statistically and clinically significant in reducing postoperative pain, and all four sources showed a reduction in opioid consumption during the immediate postoperative period, which promoted patient satisfaction. CONCLUSIONS: Further study of gabapentin and postoperative pain is needed employing rigorous and robust methodology and diversity of the sample selections.

Perioperative Dexamethasone for Patients With Diabetes and Its Effect on Blood Glucose After Surgery.

PURPOSE: P Perioperative administration of single-dose dexamethasone helps reduce postoperative nausea and vomiting, inflammation, and pain. However, it is unclear which dose achieves these effects while minimizing the hyperglycemic impact in patients with diabetes. The purpose of this review was to elucidate the most appropriate perioperative dose of dexamethasone for diabetic patients, and whether it is necessary to withhold it in patients with poor glycemic control. DESIGN: A systematic review. METHODS: A literature search using PubMed and Cochrane Database of Systematic Reviews revealed 17 potential evidence sources. Eight sources met the inclusion criteria. Sources included one systematic review with meta-analysis, one randomized control trial, and six observational studies. FINDINGS: Evidence suggests diabetic patients who receive dexamethasone perioperatively are more likely to develop postoperative hyperglycemia, with a maximum blood glucose increase of 30 to 45 mg/dL in the first 24 hours following a single dose. One study described increased blood glucose levels with escalating doses, but no other sources have supported that finding. The available studies were markedly heterogeneous in both design and proportion of diabetic subjects included, and most were of low quality. CONCLUSIONS: There is not enough evidence to quantify the hyperglycemic effect of commonly used dexamethasone doses, and rigorous studies are needed to inform practice.

Detection of insulin analogues and large peptides >2 kDa in urine.

Insulin analogues and large bioactive peptides may be used by athletes to enhance performance and are banned by the World Anti-Doping Agency (WADA). In addition to insulin analogues, the large peptides include a structurally diverse set of peptides including analogues of growth hormone releasing hormone (GHRH), insulin-like growth factor-1 (IGF-1), and mechano-growth factor (MGF). Detection of this class of peptides is difficult due to their absorptive losses and presence at very low concentrations in urine. In this report, a high throughput method is described that allows sensitive detection of four classes of large peptides in one assay. Sample extraction is performed by ultrafiltration to concentrate the urine followed by solid phase extraction in a 96-well micro-elution plate. Peptides in the urine samples are detected on a triple quadrupole mass spectrometer coupled to standard flow liquid chromatography. The method was validated and evaluated for limit of detection, limit of identification, specificity, precision, carryover, recovery, matrix interference, and post-extraction stability. The limit of detection for insulin analogues is between 5 and 25 pg/ml and between 5 and 50 pg/ml for the other peptide classes. Specificity was good with no detection of interfering peaks in blank urine samples. Carryover from a high concentration sample was not observed and the post-extraction stability was between 77% and 107%. The method was able to detect insulin analogues in three diabetic urine samples. Increased screening for this class of peptides will improve detection and deterrence.

Resuming Breastfeeding After Surgery: Influencing Practice Recommendations.

PURPOSE: Mothers often request guidance on when it is safe to resume breastfeeding after surgery. At our institution, this guidance was inconsistent and not well-grounded in current research. This project sought to bring recommendations to patients in line with current evidence about when to recommend resumption of breastfeeding after surgery. DESIGN: A local practice guideline was developed based on our systematic review, then staff were educated about the guideline. METHODS: Transfer to clinical practice was measured by reported practice recommendations. A repeated measures design measured change in provider knowledge, recommendations, and confidence in these recommendations. A follow-up assessment was conducted at 2 years to measure long-term impact. FINDINGS: After the educational session, there was a two-fold increase in the number of perianesthesia staff who recommended resumption of breastfeeding as soon as the mother had recovered from anesthesia. CONCLUSIONS: This evidence-based practice project standardized delivery of breastfeeding recommendations by perioperative staff.

Training Program for Ultrasound-Guided Intravenous Catheter Insertion.

INTRODUCTION: Ultrasound guidance is now widely available in military treatment facilities and civilian hospitals alike, both in the USA and in forward-deployed military environments. Technical mastery of ultrasound-guided peripheral intravenous (USGPIV) catheter insertion can be easily achieved through a short training course. Mastery can be achieved even when trainees have a limited medical background before course attendance. An evidence-based practice project team sought to improve the knowledge, confidence, and skills in the placement of USGPIV catheters by clinicians at Naval Hospital Jacksonville. Completion of an USGPIV training program can equip healthcare providers with knowledge and confidence for placement of peripheral access necessary in critical situations such as those requiring medications or blood products. MATERIALS AND METHODS: The project team conducted a literature review to evaluate the appropriateness of USGPIV training for the nurses and military medical technicians in this setting. The team developed and delivered a USGPIV training program based on adaptations from the literature. During the training period, knowledge and confidence scores were reported by each trainee to evaluate the perceptions of the quality of training. The number of attempted catheter placements and ultrasound utilization was recorded in the pre- and post-implementation periods to evaluate the project's effect on the delivery of patient care. Statistical analysis was conducted to evaluate project outcomes. RESULTS: In the pre-intervention period, none of the 252 intravenous catheters were placed with the USGPIV technique, compared to 50 of 267 in the post-intervention period. These results demonstrate an 18.7% increase in the USGPIV access approach by nursing staff. Mean knowledge scores significantly increased following the delivery of the training, 60% versus 80% in the pre- and post-training assessments, respectively (P < .001). Mean self-reported skill confidence scores also significantly improved (P < .001). CONCLUSION: Knowledge and self-reported confidence in USGPIV access improved for the trainees. Mean knowledge improved from 60% to 80%, while mean confidence scores increased from 2.74 to 3.79 for corpsman and from 3.0 to 3.88 for nurses. Utilization of the USGPIV technique increased by 18.7% in the post-intervention period. These results demonstrate that implementing this training program can improve knowledge, confidence, and use of ultrasound during the placement of PIV catheters.

Prevention of Pruritis following Spinal Morphine for Scheduled Cesarean Birth.

BACKGROUND: Intrathecal morphine provides effective analgesia after cesarean birth, yet up to 90% of women who receive it experience excessive itching, an undesirable dose-dependent effect. Pruritis may increase nursing workload, delay breastfeeding, and decrease patient satisfaction. When 0.1 mg spinal morphine is given, pruritis is markedly reduced while analgesia is preserved. PURPOSE: The purpose of this project was to determine possible causes and solutions for pruritus after cesarean birth. METHODS: Anesthesia providers were educated and encouraged to limit spinal morphine to 0.1 mg as a strategy to prevent pruritus. In a repeated measures design, the rate of treatment-required pruritus and opioid consumption were measured 24 hours after surgery. The project included an evaluation of 30 medical records before and 30 medical records after the project intervention. RESULTS: Preintervention rate of treatment-required pruritis was 37%, all received spinal morphine ≥ 1.5 mg. Postintervention rate of treatment-required pruritis was 13% and 57% after spinal morphine 0.1 mg and 0.2 mg, respectively. Opioid consumption was similar between groups. CLINICAL IMPLICATIONS: Mother-baby nurses can have an impact on the practice of anesthesia providers by advocating for evidence-based dosing of intrathecal morphine to reduce the incidence of pruritis while maintaining effective analgesia for women after cesarean birth.

Auricular acupuncture for adult tonsillectomy.

OBJECTIVES: Adult tonsillectomy causes significant postoperative pain that can last over 14 days, but narcotic regimens only provide a modest reduction in pain. Auricular acupuncture has been demonstrated to improve pain with minimal complications. This study compared acupuncture versus control for pain, opioid consumption, nausea, and return of diet and activity following tonsillectomy. METHODS: A prospective, single-blinded randomized controlled trial was performed on 134 adults undergoing tonsillectomy at a tertiary care teaching hospital. Each patient was randomized to receive either auricular (Battlefield protocol) acupuncture with auricular bandages or bandages alone while under general anesthesia. Subjects journaled daily postoperative pain, diet, activity, and opioid consumption, then returned to the clinic on postoperative day 14 for a final questionnaire and evaluation. RESULTS: Ninety-nine patients completed the study with 50 patients in the acupuncture group and 49 patients in the control group. Pain scores for the acupuncture group following tonsillectomy were significantly lower than the control group on the day of surgery (2.9, 4.3; P = .01), but there was no statistically significant difference in pain thereafter. There was an equivalent level of postoperative narcotic usage, nausea, emesis, functional activity and diet between the two groups. The main complication following tonsillectomy was secondary hemorrhage and there was no significant difference between the two groups (20%, 10%; P = .13). CONCLUSION: Auricular acupuncture provides increased pain relief on the day of surgery, an effect that seems to diminish after 24 hours. LEVEL OF EVIDENCE: 1b Laryngoscope, 130: 1907-1912, 2020.

Three-dimensional reconstruction of leukocyte internalisation in the luminal uterine epithelium following mating.

Following mating, leukocytes are recruited to the uterine epithelium where they phagocytose spermatozoa and mediate maternal immune tolerance as well as a mild inflammatory response. In this ultrastructural study we utilised array tomography, a high-resolution volume scanning electron microscopy approach to 3D reconstruct the cellular relationships formed by leukocytes recruited to the luminal uterine epithelium 12 h post-mating in the rat. We report that following mating, neutrophils and macrophages are internalised by the luminal uterine epithelium, with multiple leukocytes internalised via contortion through a small tunnel in the apical membrane into a large membrane-bound vacuole within the cytoplasm of luminal uterine epithelial cells (UECs). Once internalised within the UECs, recruited leukocytes appear to phagocytose material within the membrane-bound vacuole and most ultimately undergo a specialised cell death, including vacuolisation and loss of membrane integrity. As these observations involve ultrastructurally normal leukocytic cells internalised within non-phagocytic epithelial cells, these observations are consistent with the formation of cell-in-cell structures via entosis, rather than phagocytic engulfment by UECs. Although cell-in-cell structures have been reported in normal and pathological conditions elsewhere, the data collected herein represents the first evidence of the formation of cell-in-cell structures within the uterine epithelium as a novel component of the maternal inflammatory response to mating.

Identification and Management of Ischemic Stroke in the Postanesthesia Care Unit.

A thromboembolic stroke is a debilitating event that can occur with little or no warning. This report details the case of a 63-year-old male experiencing a stroke in the immediate postoperative period after total knee arthroplasty. Risk for perioperative stroke is influenced by age, sex, ethnicity, comorbidities, and some medications. The depressed neurocognitive state of patients recovering from anesthesia warrants special consideration for the identification and management of perioperative stroke.

Hypothalamic-Pituitary-Testicular Axis Effects and Urinary Detection Following Clomiphene Administration in Males.

Context: Clomiphene is a performance-enhancing drug commonly abused by males in sport, but the extent to which testosterone increases in healthy males following its use is unknown. In addition, evidence suggests that clomiphene, a mixture of cis- and trans-isomers zuclomiphene and enclomiphene, is detectable in urine for months following use; the isomer-specific urinary detection window has yet to be characterized in a controlled study. Objective: To determine the effect of once-daily, 30-day clomiphene treatment on serum testosterone and gonadotropin levels in the subject population studied and the urinary clearance and detection window of clomiphene isomers following administration for antidoping purposes. Participants and Design: Twelve healthy males aged 25 to 38 years, representing a recreational athlete population, participated in this open-label, single-arm study. Intervention: Oral clomiphene citrate (50 mg) was self-administered once daily for 30 days. Serum and urine samples were collected at baseline and at days 7, 14, 21, 28, 30, 32, 35, 37, 44, 51, and 58; urine collections continued periodically up to day 261. Results: Mean testosterone, LH, and FSH levels increased 146% (SEM, ±23%), 177% (±34%), and 170% (±33%), respectively, during treatment compared with baseline. Serum drug concentrations and urinary excretion were nonuniform among individuals as isomeric concentrations varied. The zuclomiphene urinary detection window ranged from 121 to >261 days. Conclusions: Clomiphene significantly raised serum testosterone and gonadotropin levels in healthy men and thus can be abused as a performance-enhancing drug. Such abuse is detectable in urine for ≥4 months following short-term use.

Implementation of an Education Program for an Ultrasound-Guided Liposomal Bupivacaine Transversus Abdominis Plane (TAP) Block Protocol for Open Abdominal Procedures.

Anesthesia practitioners at the authors' facility had varying education and training with placing transversus abdominis plane (TAP) blocks and with the use of liposomal bupivacaine limiting the utilization of this regional anesthetic technique for patients undergoing abdominal surgical procedures. An expansive literature review suggested that ultrasound-guided liposomal bupivacaine TAP blocks were safe and effective for reducing postoperative pain scores, opioid use, and no reported adverse effects. Current literature findings were used to craft an educational intervention to update current practices among anesthesia practitioners. The purpose of the project was to develop and implement an educational intervention to improve the knowledge and confidence of all anesthesia providers at our facility when placing and managing liposomal bupivacaine TAP blocks in patients undergoing abdominal surgery. We used the Ajzen Theory of Planned Behavior to create an effective practice change, combined with skill acquisition through simulation, among anesthesia providers at our facility in performing ultrasound-guided liposomal bupivacaine TAP blocks. The implementation of a multistrategy education program using simulation resulted in a significant increase in knowledge and confidence among anesthesia practitioners.

Increasing Access to Auricular Acupuncture for Postoperative Nausea and Vomiting.

PURPOSE: Postoperative nausea and vomiting (PONV) affects more than 30% of surgical patients. Auricular acupuncture (AA) has been shown to decrease the incidence of PONV in select populations. DESIGN: An evidence-based quality improvement project made AA available to all adult surgical patients, and the results were recorded in a database. A retrospective between-groups analysis of 210 database entries was conducted, of those 25 receiving AA. FINDINGS: More risk factors for PONV were present in the AA group (P < .001). Both groups experienced a less-than-expected rate of PONV. Similar rates were shown between groups for PONV, postanesthesia care unit length of stay, and opioid consumption. Patient satisfaction was 96% with AA. The AA group was treated with less antiemetic medication (P < .001), yet PONV rates remained similar. CONCLUSIONS: A multimodal approach treating patients at risk for PONV is recommended. Administration of multiple antiemetics may result in unnecessary cost or unfavorable side effects when effective and less costly alternatives exist. AA is a viable treatment for PONV, considering cost and patient satisfaction.

Correlated light and electron microscopy observations of the uterine epithelial cell actin cytoskeleton using fluorescently labeled resin-embedded sections.

In order to perform correlative light and electron microscopy (CLEM) more precisely, we have modified existing specimen preparation protocols allowing fluorescence retention within embedded and sectioned tissue, facilitating direct observation across length scales. We detail a protocol which provides a precise correlation accuracy using accessible techniques in biological specimen preparation. By combining a pre-embedding uranyl acetate staining step with the progressive lowering of temperature (PLT) technique, a methacrylate embedded tissue specimen is ultrathin sectioned and mounted onto a TEM finder grid for immediate viewing in the confocal and electron microscope. In this study, the protocol is applied to rat uterine epithelial cells in vivo during early pregnancy. Correlative overlay data was used to track changes in filamentous actin that occurs in these cells from fertilization (Day 1) to implantation on Day 6 as part of the plasma membrane transformation, a process essential in the development of uterine receptivity in the rat. CLEM confirmed that the actin cytoskeleton is disrupted as apical microvilli are progressively lost toward implantation, and revealed the thick and continuous terminal web is replaced by a thinner and irregular actin band, with individually distinguishable filaments connecting actin meshworks which correspond with remaining plasma membrane protrusions.

Metabolism of beclomethasone dipropionate by cytochrome P450 3A enzymes.

Inhaled glucocorticoids, such as beclomethasone dipropionate (BDP), are the mainstay treatment of asthma. However, ≈ 30% of patients exhibit little to no benefit from treatment. It has been postulated that glucocorticoid resistance, or insensitivity, is attributable to individual differences in glucocorticoid receptor-mediated processes. It is possible that variations in cytochrome P450 3A enzyme-mediated metabolism of BDP may contribute to this phenomenon. This hypothesis was explored by evaluating the contributions of CYP3A4, 3A5, 3A7, and esterase enzymes in the metabolism of BDP in vitro and relating metabolism to changes in CYP3A enzyme mRNA expression via the glucocorticoid receptor in lung and liver cells. CYP3A4 and CYP3A5 metabolized BDP via hydroxylation ([M4] and [M6]) and dehydrogenation ([M5]) at similar rates; CYP3A7 did not metabolize BDP. A new metabolite [M6], formed by the combined action of esterases and CYP3A4 hydroxylation, was also characterized. To validate the results observed using microsomes and recombinant enzymes, studies were also conducted using A549 lung and DPX2 liver cells. Both liver and lung cells produced esterase-dependent metabolites [M1-M3], with [M1] correlating with CYP3A5 mRNA induction in A549 cells. Liver cells produced both hydroxylated and dehydrogenated metabolites [M4, M5, and M6], but lung cells produced only the dehydrogenated metabolite [M5]. These studies show that CYP3A4 and CYP3A5 metabolize BDP to inactive metabolites and suggest that differences in the expression or function of these enzymes in the lung and/or liver could influence BDP disposition in humans.

Regulation of CYP3A genes by glucocorticoids in human lung cells.

Inhaled glucocorticoids are the first-line treatment for patients with persistent asthma.  However, approximately thirty percent of patients exhibit glucocorticoid insensitivity, which may involve excess metabolic clearance of the glucocorticoids by CYP3A enzymes in the lung.  CYP3A4, 3A5, and 3A7 enzymes metabolize glucocorticoids, which in turn induce CYP3A genes.  However, the mechanism of CYP3A5 mRNA regulation by glucocorticoids in lung cells has not been determined.  In hepatocytes, glucocorticoids bind to the glucocorticoid receptor (GR), which induces the expression of the constitutive androstane receptor or pregnane X receptor; both of which bind to the retinoid X receptor alpha, leading to the induction of CYP3A4, 3A5, and 3A7.  There is also evidence to suggest a direct induction of CYP3A5 by GR activation in liver cells. In this study, these pathways were evaluated as the mechanism for CYP3A5 mRNA induction by glucocorticoids in freshly isolated primary tracheal epithelial, adenocarcinomic human alveolar basal epithelial (A549), immortalized bronchial epithelial (BEAS-2B), primary normal human bronchial/tracheal epithelial (NHBE), primary small airway epithelial (SAEC), and primary lobar epithelial lung cells. In A549 cells, beclomethasone 17-monopropionate ([M1]) induced CYP3A5 mRNA through the glucocorticoid receptor. CYP3A5 mRNA induction by five different glucocorticoids was attenuated by inhibiting the glucocorticoid receptor using ketoconazole, and for beclomethasone dipropionate, using siRNA-mediated knock-down of the glucocorticoid receptor. The constitutive androstane receptor was not expressed in lung cells. SAEC cells, a primary lung cell line, expressed CYP3A5, but CYP3A5 mRNA was not induced by glucocorticoid treatment despite evaluating a multitude of cell culture conditions. None of the other lung cells expressed CYP3A4, 3A5 or 3A7 mRNA. These studies demonstrate that CYP3A5 mRNA is induced by glucocorticoids in A549 cells via the glucocorticoid receptor, but that additional undefined regulatory processes exist in primary lung cells.