P-glycoprotein (P-gp), Breast cancer resistance protein (BCRP) and Multidrug resistance-associated protein 2 (MRP2) residing at the blood-brain barrier (BBB) and the blood-spinal cord barrier (BSCB) are major obstacles for drug delivery to the Central Nervous System (CNS). Disease-induced changes of these xenobiotic transporters at the CNS barriers have been previously documented. Changes in the functional expression of these transporters at the CNS barriers would limit the clinical efficacy of therapeutic agents targeting the CNS. In this study, we characterized the changes in expression and efflux activity of P-gp, BCRP and MRP2 at the BBB and BSCB of an amyotrophic lateral sclerosis (ALS) SOD1-G93A transgenic rat model across the three stages of disease progression: pre-onset, onset and symptomatic. Up-regulation of P-gp and BCRP at the BBB and BSCB during disease progression of ALS would reduce drug entry to the CNS, while any decreases in transport activity would increase drug entry. In SOD rats at the ALS symptomatic stage, we observed increases in both P-gp transport activity and expression compared to age-matched wildtypes. BCRP and MRP2 levels were unchanged in these animals. Immunohistochemical analysis in brain and spinal cord capillaries of SOD rats from all three ALS stages and age-matched wildtypes showed no differences in nuclear localization of a known P-gp regulator, nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB). It suggests that NFκB may have a limited role during P-gp induction observed in our study and additional signaling pathways could be responsible for this response. Our observations imply that novel pharmacological approaches for treating ALS require selecting drugs that are not P-gp substrates in order to improve therapeutic efficacy in the CNS during ALS progression.

The blood-brain barrier is a microvascular network that (1) provides neuroprotection from metabolic and environmental toxins and (2) limits the delivery of therapeutics to the central nervous system (CNS). The ATP-binding cassette transporter P-glycoprotein contributes to the latter by actively pumping clinical substrates back into circulation before they can reach the brain parenchyma. Targeting P-glycoprotein has proven effective in increasing the delivery of therapeutics to their cerebral targets. We provide a novel mechanism to achieve this end in functioning, intact rat brain capillaries, whereby the bioactive phospholipid lysophosphatidic acid (LPA) and tricyclic antidepressant (TCA) amitriptyline reduce basal P-glycoprotein transport activity through a distinct lysophosphatidic acid 1 receptor-mediated signaling cascade that requires G-protein coupling, Src kinase, and ERK 1/2. Furthermore, we demonstrate the ability of LPA and TCA amitriptyline to decrease induced P-glycoprotein transport activity in a human SOD1 transgenic rat model of amyotrophic lateral sclerosis. This work may translate to new clinical strategies for increasing the cerebral penetration of therapeutics in patients suffering from CNS diseases marked by exacerbated pharmacoresistance.

Five marketing practices which are often at variance with FDA drug advertising regulations are discussed: 1. Use of industry-sponsored scientific and educational activities, 2. Activities lacking in scientific legitimacy, 3. Use of public relations, 4. Direct-to-consumer promotion of prescription drug products, and 5. Industry activi ties related to promotional materials subject to Food and Drug Administration preapproval. Areas of FDA concern, industry trends, and regulatory responses are discussed for each of these practices. THESE ARE STRESSFUL times at the Food and Drug Administration (FDA).With the generic drug and other contro versies, Congress and the media have scru tinized the agency and raised questions about the honesty and judgement of the staff, as well as the legitimacy of the drug and device approval processes. A recent network television program described the FDA as "overwhelmed and understaffed," with the reporter concluding that "never before has FDA been under such a cloud."The FDA Division of Drug Advertising has not been directly impacted by the ge neric drug investigation, but we have not escaped scrutiny. A recent network televi sion program examined the case of Tambocor, in which Riker Laboratories con tinued, over our objections, to promote their product for administration to a wid er range of arrhythmia patients than we believed appropriate. The FDA was de scribed as a "toothless tiger" in terms of our perceived ability to control the pro motional practices of the industry. Anoth er network television program discussed Ortho's public activities related to unap proved uses of Retin-A, which have con tinued while "under investigation" by the agency.We are reminded of the old adage: When we thought, "Cheer up, things could be worse," we cheered up and sure enough, things got worse. In the coming 639

Several mouse models have been developed to study polycystic ovarian syndrome (PCOS), a leading cause of infertility in women. Treatment of mice with dihydrotestosterone (DHT) for 90-days causes ovarian and metabolic phenotypes similar to women with PCOS. We used this 90-day DHT treatment paradigm to investigate the variable incidence and heterogeneity in two inbred mouse strains, NOD/ShiLtJ and 129S1/SvlmJ. NOD mice naturally develop type 1 diabetes, and recent meta-analysis found increased androgen excess and PCOS in women with type 1 diabetes. 129S1 mice are commonly used in genetic manipulations. Both NOD and 129S1 DHT treated mice had early vaginal opening, increased anogenital distance and altered estrus cycles compared to control animals. Additionally, both NOD and 129S1 mice had reduced numbers of corpora lutea after DHT exposure, while NOD mice had decreased numbers of preantral follicles and 129S1 mice had reduced numbers of small antral follicles. NOD mice had increased body weight, decreased white adipocyte size, and improved glucose sensitivity in response to DHT, while 129S1 mice had increased body weight and white adipocyte size. NOD mice had increased expression of Adiponectin, Cidea, Srebp1a and Srebp1b and 129S1 mice had decreased Pparg in the white adipose tissues, while both NOD and 129S1 mice had increased expression of Glut4 and Prdm16 suggesting DHT may differentially affect glucose transport, thermogenesis, and lipid storage in white adipose tissue. DHT causes different ovarian and metabolic responses in NOD and 129S1 mice suggesting that strain differences may allow further elucidation of genetic contributions to PCOS.