The gasotransmitters are a family of gaseous signaling molecules which are produced endogenously and act at specific receptors to play imperative roles in physiologic and pathophysiologic processes. As a well-known gasotransmitter along with hydrogen sulfide and carbon monoxide, nitric oxide (NO) has earned repute as a potent vasodilator also known as endothelium-derived vasorelaxant factor (EDRF). NO has been studied in greater detail, from its synthesis and mechanism of action to its physiologic, pathologic, and pharmacologic roles in different disease states. Different animal models have been applied to investigate the beneficial effects of NO as an antihypertensive, renoprotective, and antihypertrophic agent. NO and its interaction with different systems like the renin–angiotensin system, sympathetic nervous system, and other gaseous transmitters like hydrogen sulfide are also well studied. However, links that appear to exist between the endocannabinoid (EC) and NO systems remain to be fully explored. Experimental approaches using modulators of its synthesis including substrate, donors, and inhibitors of the synthesis of NO will be useful for establishing the relationship between the NO and EC systems in the cardiovascular and renal systems. Being a potent vasodilator, NO may be unique among therapeutic options for management of hypertension and resulting renal disease and left ventricular hypertrophy. Inclusion of NO modulators in clinical practice may be useful not only as curatives for particular diseases but also for arresting disease prognoses through its interactions with other systems.

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'NBOMe' (dimethoxyphenyl-N-[(2-methoxyphenyl)methyl]ethanamine) derivatives are a new class of designer hallucinogenic drugs widely available on the Internet. Currently, 2-(4-iodo-2,5-dimethoxyphenyl)-N-[(2-methoxyphenyl)methyl]ethanamine (25I-NBOMe) is the most popular abused derivative in the USA. There are little published data on the absorption, metabolism and elimination of 25I-NBOMe, or any of the other NBOMe derivatives. Therefore, there are no definitive metabolite biomarkers. We present the identification of fifteen 25I-NBOMe metabolites in phase I and II mouse hepatic microsomal preparations, and analysis of two human urine samples from 25I-NBOMe-intoxicated patients to test the utility of these metabolites as biomarkers of 25I-NBOMe use. The synthesis of two major urinary metabolites, 2-iodo-4-methoxy-5-[2-[(2-methoxyphenyl) methylamino]ethyl]phenol (2-O-desmethyl-5-I-NBOMe, M5) and 5-iodo-4-methoxy-2-[2-[(2-methoxyphenyl)methylamino]ethyl]phenol (5-O-desmethyl-2-I-NBOMe), is also presented. Seven phase II glucuronidated metabolites of the O-desmethyl or the hydroxylated phase I metabolites were identified. One human urine sample contained 25I-NBOMe as well as all 15 metabolites identified in mouse hepatic microsomal preparations. Another human urine sample contained no parent 25I-NBOMe, but was found to contain three O-desmethyl metabolites. We recommend β-glucuronidase enzymatic hydrolysis of urine prior to 25I-NBOMe screening and the use of M5 as the primary biomarker in drug testing.

Lysosomal acid ceramidase (Ac) has been shown to be critical for ceramide hydrolysis and regulation of lysosome function and cellular homeostasis. In the present study, we generated a knockout mouse strain (Asah1 fl/fl /Podo Cre ) with a podocyte-specific deletion of the a subunit (main catalytic subunit) of Ac. Although no significant morphologic changes in glomeruli were observed in these mice under light microscope, severe proteinuria and albuminuria were found in these podocyte-specific knockout mice compared with control genotype littermates. Transmission electron microscopic analysis showed that podocytes of the knockout mice had distinctive foot process effacement and microvillus formation. These functional and morphologic changes indicate the development of nephrotic syndrome in mice bearing the Asah1 podocyte-specific gene deletion. Ceramide accumulation determined by liquid chromatographyetandem mass spectrometry was demonstrated in isolated glomeruli of Asah1 fl/fl / Podo Cre mice compared with their littermates. By crossbreeding Asah1 fl/fl /Podo Cre mice with Smpd1 À/À mice, we also produced a double knockout strain, Smpd1 À/À /Asah1 fl/fl /Podo Cre , that also lacks Smpd1, the acid sphingomyelinase that hydrolyzes sphingomyelin to ceramide. These mice exhibited significantly lower levels of glomerular ceramide with decreased podocyte injury compared with Asah1 fl/fl / Podo Cre mice. These results strongly suggest that lysosomal Ac in podocytes is essential for the maintenance of the structural and functional integrity of podocytes.

Tianeptine (7-[([3-chloro-6,11]-dihydro-6-methyldibenzo[c,f][1,2]thiazepin-11-yl) amino] heptanoic acid S, S dioxide) is a tricyclic compound prescribed as an antidepressant in European countries, but is not currently approved for use in the United States. There are few published case reports of tianeptine intoxication. Presented is the first case of acute toxicity associated with the intravenous use of tianeptine. A 36-year-old male intentionally injected tianeptine powder intravenously to "help him see into the future". He became unresponsive and a bystander called emergency medical services. Upon arrival to the Emergency Department, excessive constriction of the pupils, sedation, and a respiratory rate of 6 respirations per minute (rpm) were noted. Blood and urine were collected ~2 h post admission. The patient's serum ethanol concentration was 133 mg/dL. His toxicity was successfully reversed with two doses of naloxone 0.4 mg IV. He was started on a naloxone infusion at 0.2 mg/h and discharged 13 h after admittance awake, alert and oriented. The patient's urine sample screened negative for common drugs of abuse and total tricyclic antidepressants. A high performance liquid chromatography tandem mass spectrometry method was developed and validated to quantify tianeptine in urine. The calibration range was 1-100 ng/mL with linear regression correlation (r2) of 0.9996 or greater. The limit of quantitation was administratively set at 1 ng/mL. The bias of the assay was determined to be within ±20% of the target value for each quality control specimen. The intra-day and inter-day precision did not exceed 15% coefficient of variation for each quality control specimen. Matrix effects, absolute recovery, carryover and specificity were also evaluated. The patient's tianeptine urine concentration was determined to be 2 ng/mL.