The dependence of the incorporation of methamphetamine into rat hair on dose,frequency of administration and hair pigmentation

In this paper, the incorporation of methamphetamine (MA) into rat hair was studied. The main purpose of this study was to investigate whether MA can be detected or positive hair results can be obtained in hair of rats administered a single dose of MA. The relationship between dose and frequency of administration and the concentrations of MA and its metabolite, amphetamine (AP), in rat hair were evaluated and the MA and AP concentrations in white and pigmented hair were compared. MA was administered to rats as follows: low dose (0.5 mg/kg/day), medium dose (2 mg/kg/day) and high dose (10 mg/kg/day). The frequency of administration was one time per day for 1, 2, 3, 4, 5, 15 and 30 days. Hair and urine samples were collected from rats and analyzed by gas chromatography/mass spectrometry (GC/MS). MA could be identified in pigmented rat hair when MA was administered for 4 or more days at low daily dose and on day 1 following administration of medium and high daily doses. Positive results for MA were obtained from pigmented rat hair when MA was administered for 30 days at low daily dose, for 4 or more days at medium daily dose, or for 2 or more days at high daily dose. The concentrations of MA and AP found in rat hair were proportional to the dose and frequency of administration. The concentrations of MA and AP in pigmented rat hair were 2–10 times higher than those in white rat hair. The results of this study on the incorporation of MA into rat hair can serve as a model to better understand the incorporation of MA into human hair even though there are differences between animal models and human hair.     

Single hair analysis of methamphetamine and amphetamine by solid phase microextraction coupled with in matrix derivatization

A sensitive method for detection of methamphetamine (MA) and amphetamine (AP) in human hair was developed using solid phase microextraction (SPME) and one-pot derivatization. MA and AP were directly derivatized to N-propoxycarbonyl derivatives in an aqueous solution by propylchloroformate in a one-pot reaction before extraction by SPME. The derivatives were extracted to a coating of SPME from a headspace of the vial. The adsorbed derivatives were thermally desorbed in the injection port of a gas chromatograph. Pentadeuterated MA was used as an internal standard. The absolute recoveries of MA and AP from the spiked hair were 2.80-17.5%, respectively. The calibration curves showed linearity in the range of 0.05-20 ng/0.08 mg/vial for MA and 0.1-20 ng/0.08 mg/vial for AP in hair. Detection limits (S/N = 3) of MA and AP were 0.02 and 0.05 ng/0.08 mg/vial. The coefficients of variation of intraday were 1.04-26.4%. Additionally, this proposed method was applied to segmental analysis in clinical and medico-legal cases of MA intoxication.     

Development of a reference material using methamphetamine abusers' hair samples for the determination of methamphetamine and amphetamine in hair

In the present study, we developed a reference material (RM) using authentic hair samples for the determination of methamphetamine (MA) and its main metabolite, amphetamine (AP) in human hair. MA abusers' hair samples were collected, homogenized and finally bottled. The concentration of each bottle was determined using two extraction methods, agitation with 1% HCl in methanol at 38 degrees C and ultrasonication with methanol/5M HCl (20:1), followed by gas chromatography/mass spectrometry (GC-MS) after derivatization with trifluoroacetic anhydride (TFAA). Both analytical procedures were fully validated and their extraction efficiency was compared. The homogeneity of analytes was evaluated and their property values were determined with their uncertainties. The two methods were acceptable to analyze MA and AP in human hair through the validation and comparative studies using spiked and authentic hair samples as well as NIST SRM 2379 certified reference material. Satisfying homogeneity was reached for MA and AP in the prepared RM. Finally, a human hair RM containing MA and AP is prepared at the level of 7.64+/-1.24 and 0.54+/-0.07 ng/mg, respectively. This material can be useful in forensic laboratories for internal quality control and external quality assurance.     

Routine analysis of amphetamine and methamphetamine in biological materials by gas chromatography-mass spectrometry and on-column derivatization

A simple determination method of amphetamine (AP) and methamphetamine (MA) in biological materials was developed using on-column derivatization and gas chromatography-mass spectrometry (GC-MS). AP and MA in biological materials were adsorbed on the surface of Extrelut and then extracted and derivatized simultaneously on the Extrelut column. AP and MA were derivatized to the N-propoxycarbonyl derivatives using propylchloroformate. Pentadeuterated MA was used as an internal standard. The recoveries of AP and MA from urine were 88.2 and 92.5%, and those from blood were 89.7 and 90.3%, respectively. The calibration curves showed linearity in the range of 12.5-2000 ng/ml (ng/g) for AP and MA in urine and blood, and 0.25-20 ng/mg in hair. When urine samples containing two different concentrations (200 and 1000 ng/ml) of AP and MA, blood samples containing two different concentrations (200 and 1000 ng/g) of AP and MA, hair samples containing two different concentrations (0.5 and 5.0 ng/mg) of AP and MA, the coefficients of variation of intra-day and inter-day were 0.68-3.60% in urine, 0.42-4.58% in blood, and 1.20-13.1% in hair. Furthermore, this proposed method was applied to a medico-legal case of MA intoxication.     

Hair analysis for drugs of abuse XXI. Effect of para-substituents on benzene ring of methamphetamine on drug incorporation into rat hair

In order to study the effect of para-substituents on the benzene ring of methamphetamine on drug incorporation into hair from blood, the plasma AUCs and hair concentrations of 7 methamphetamines [methamphetamine(MA), p-hydroxymethamphetamine(OHMA), p-bromomethamphetamine (BMA), p-aminomethamphetamine (AMA), p-nitromethamphetamine (NMA), p-methoxymethamphetamine (MOMA) and 3,4-methylenedioxymethamphetamine (MDMA)] plus propylhexedrine(PHX) in DA rats was determined after intraperitoneal injection at 5 mg/kg, with single dose for the plasma AUC and 10 doses for the hair concentration. Drug incorporation rates into hair (ICRs) were calculated by dividing each hair concentration by each plasma AUC. Comparing the highest value (NMA) to the lowest one (OHMA), the ICR of NMA was 31.7 times larger than that of OHMA. Using the ICR of MA which has no substitute on the benzene ring as a base point, nitro, bromo, methylenedioxy, methoxy and amino groups raised the drug incorporation into rat hair in this order. On the other hand, hydroxy substitution showed a negative effect on the ICR. In comparison between the ICRs of MA and PHX, it was found that the benzene ring shows higher affinity to melanin and less lipophilicity than the cyclohexyl ring. Our results showed that there is a relatively strong effect of the functional groups on drug incorporation into hair. The combination of melanin affinity and lipophilicity are clearly correlated with their ICR.     

Application of ion mobility spectrometry to the rapid screening of methamphetamine incorporated in hair

Using ion mobility spectrometry (IMS), a simple, sensitive and rapid screening for methamphetamine (MA) incorporated in user's hair has been developed. To completely unbind MA from hair matrix and to achieve its effective vaporization for the IMS detection, the hair sample was digested in 5 M NaOH (methanol-water, 4:1, v/v) solution prior to IMS measurement. MA in hair was semi-quantitatively detected by monitoring the digested hair sample employing dibenzylamine (DBA) as internal standard. The minimum amount of hair sample required was 2 mg and its digested sample was ample for four IMS measurements. Teh detection limit of MA in hair was 0.5 ng mg⁻¹. This proposed method was applicable to the semi-quantitative detection of MA in users' hair samples, and to the sectional analysis for MA in a limited amount of user's hair. The IMS results obtained were in good agreement with their GC-MS determination.     

Simultaneous determination of amphetamine,methamphetamine, 3,4-methylenedioxyamphetamine and 3,4-methylenedioxymethamphetamine in human hair by gas chromatography-mass spectrometry

A procedure is presented for the simultaneous identification and quantification of amphetamine (AP), methamphetamine (MA), methylenedioxyamphetamine (MDA) and methylenedioxymethamphetamine (MDMA) in human hair. The method involves decontamination of hair with dichloromethane and warm water, heat-alkaline hydrolysis in the presence of deuterated internal standards, liquid-liquid extraction and gas chromatography-mass spectrometry after derivatization with pentafluoropropionic anhydride-pentafluoropropanol. The limit of detection for AP, MA and MDA was 0.05 ng/mg using a 50-mg hair sample; for MDMA it was 0.1 ng/mg. Coefficients of variation ranged from 7 to 18%. This assay has been successfully utilized in the evaluation of the deposition of the drugs in hair obtained from various parts of the anatomy of a stimulant abuser.     

Sensitivity to psychostimulants in mice bred for high and low stimulation to methamphetamine

Methamphetamine (MA) and cocaine induce behavioral effects primarily through modulation of dopamine neurotransmission. However, the genetic regulation of sensitivity to these two drugs may be similar or disparate. Using selective breeding, lines of mice were produced with extreme sensitivity (high MA activation; HMACT) and insensitivity (low MA activation; LMACT) to the locomotor stimulant effects of acute MA treatment. Studies were performed to determine whether there is pleiotropic genetic influence on sensitivity to the locomotor stimulant effect of MA and to other MA- and cocaine-related behaviors. The HMACT line exhibited more locomotor stimulation in response to several doses of MA and cocaine, compared to the LMACT line. Both lines exhibited locomotor sensitization to 2 mg/kg of MA and 10 mg/kg of cocaine; the magnitude of sensitization was similar in the two lines. However, the lines differed in the magnitude of sensitization to a 1 mg/kg dose of MA, a dose that did not produce a ceiling effect that may confound interpretation of studies using higher doses. The LMACT line consumed more MA and cocaine in a two-bottle choice drinking paradigm; the lines consumed similar amounts of saccharin and quinine, although the HMACT line exhibited slightly elevated preference for a low concentration of saccharin. These results suggest that some genes that influence sensitivity to the acute locomotor stimulant effect of MA have a pleiotropic influence on the magnitude of behavioral sensitization to MA and sensitivity to the stimulant effects of cocaine. Further, extreme sensitivity to MA may protect against MA and cocaine self-administration.     

Effects of intracerebroventricular administration of D,L-2-amino-5-phosphonovaleric acid, an N-methyl-D-aspartate receptor antagonist, on luteininizing hormone release in ovariectomized lambs.

To determine whether endogenous glutamate and aspartate control LH secretion via N-methyl-D-aspartate (NMDA) receptors in the sheep, we evaluated the effects of the NMDA receptor antagonist D,L-2-amino-5-phosphonovaleric acid (AP5) on secretion of LH in ovariectomized lambs. Twelve lambs were ovariectomized and surgically implanted with lateral cerebroventricular cannulae. At the time of the experiment, (38 wk of age) they received intracerebrally 4 injections of either 50 (n = 4), 100 (n = 4), or 200 micrograms (n = 4) of AP5. Blood samples were collected every 10 min for 8 h with animals receiving AP5 at hours 4, 5, 6, and 7. Patterns of LH during the preinjection period were compared to those during the period encompassing AP5 injections. Mean concentrations of LH were lower during AP5 injections than during the preinjection periods, a response that was not influenced by dose (0.87 +/- 0.08 vs. 0.69 +/- .07 ng/ml; p < 0.01). LH pulse amplitude decreased during AP5 treatment relative to the preinjection periods, but this difference was not statistically significant (0.79 +/- 0.11 vs. 0.68 +/- 0.10 ng/ml; p = 0.09). There were no effects of AP5 on LH pulse frequency (1.00 +/- 0.10 vs. 0.83 +/- 0.15 pulses/h for injection and preinjection periods; p > 0.10). A second experiment was done to evaluate a higher dose of AP5. Four animals were chosen to receive 4 injections of 2 mg of AP5 in a design identical to that used in the first experiment.     

Hair to document exposure to glibenclamide

Among the drugs that are used to incapacitate victims such as kids or elderly for sedation or for criminal gain such as sexual offences or robberies, glibenclamide, an antidiabetic was never mentioned. To document the interest of hair testing in such forensic situations, we have developed an original method to test for glibenclamide. A 30-year-old man was admitted to the Emergency Unit for coma and seizures after a party with some members of his family. Blood glucose was 0.40 g/l. A hair specimen was collected several weeks after the event and divided into two segments of 2 cm. Twenty milligrams of each segment cut into small pieces were incubated overnight in a phosphate buffer (pH 5.5), in presence of gliclazide used as internal standard (IS). A liquid/liquid extraction was realized with a mixture of diethyl ether/methylene chloride, and hair extract was separated on a XTerra MS C18 column using a gradient of acetonitrile and formate buffer. Detection of glibenclamide was achieved using two transitions: m/z 493.9 to 168.9 and 493.9 to 368.8. Linearity was observed from 5 to 1000 pg/mg (r2 = 0.956) with a limit of quantification at 5 pg/mg and a clean-up recovery of about 61%. Within-batch precision and bias were 9.0 and 9.5%, respectively. Ion suppression tested on drug-free hair was about 50%. Glibenclamide tested positive in the two consecutive segments (root to 2 cm: 23 pg/mg and 2-4 cm: 31 pg/mg). These findings were in accordance with a repetitive exposure to the drug. The concentrations were compared with those obtained after a single and a daily dose administration. In the hair of a subject receiving a single 5mg dose and collected 4 weeks later, glibenclamide was detected in the proximal segment at 5 pg/mg. After a 20 mg/day dose, the hair concentration of a subject under glibenclamide therapy was 650 pg/mg.     

The RBE for skin tumors and hair follicle damage in the rat following irradiation with alpha particles and electrons

Rat skin was irradiated with cyclotron-accelerated alpha particles with doses ranging from 210 rads to 6850 rads and monoenergetic electrons with doses ranging from 810 rads to 12,300 rads. The beams were modified so that the depth-dose curves were approximately identical with penetrations of about 1.0 mm. Tumors were counted every 4 weeks for 80 weeks, and at death or sacrifice the hair follicle damage was assessed by using "whole mounts" of separated epithelium. The RBE values determined from a comparison of the dose response curves were: acute skin injury, RBE = 3.0+/-1.0; hair follicle survival, RBE = 2.1 +/- 0.7; hair follicle damage, RBE = 2.6 = 0.4; tumor induction, RBE = 2.9+/- 0.5. Within the experimental error, these values were independent of the dose. For both types of radiation, the tumor incidence increased approximately as the square of time and at low doses approximately as the 4th power of dose. The histological characteristics of the tumors and the correlation between the incidence of tumors and damaged hair follicles were independent of the type of radiation. The results were consistent with the hypothesis that structural damage to the hair follicles is a factor in the tumor induction process.     

Development and validation of a gas chromatography-mass spectrometry assay for hair analysis of amphetamine, methamphetamine and methylenedioxy derivatives

A procedure based on gas chromatography-mass spectrometry (GC-MS) is described for the determination of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA, ecstasy), 3,4-methylenedioxyethylamphetamine (MDE or MDEA) and N-methyl-1-(3,4-methylenedioxyphenyl)-2-butanamine (MBDB) in hair. Hair samples were digested with 1 M sodium sulfide at 37 degrees C (by shaking for 3 h and was kept at room temperature overnight), and extracted with two sequential extraction procedures: liquid-liquid extraction with tert-butyl methyl ether and solid-phase extraction with Bond-Elut Certify columns. Extracted analytes were derivatised with N-methyl-bis(trifluoroacetamide), separated by a 5% phenylmethylsilicone column and determined by a mass spectrometer detector in selected ion monitoring mode. A good reproducibility (intra-assay R.S.D.=1.5-15.7%), accuracy (intra-assay error = 2.0-11.7%) and sensitivity (LOD=0.03-0.08 ng/mg hair) were attained. The method was successfully applied to the analysis of the proximal (1 cm) hair segment to assess recent self-reported use in "ecstasy" consumers. Otherwise, further studies are needed to validate methodology developed in case of amphetamine consumption.     

Simultaneous determination of dimethylamphetamine and its metabolites in rat hair by gas chromatography–mass spectrometry

In order to study the disposition of dimethylamphetamine (DMAP) and its metabolites, DMAP N-oxide, methamphetamine (MA) and amphetamine (AP), from plasma to hair in rats, a simultaneous determination method for these compounds in biological samples using gas chromatography–mass spectrometry with selected ion monitoring (GC–MS-SIM) was developed. As DMAP N-oxide partially degrades to DMAP and MA during GC–MS analysis, it was necessary to avoid conditions which co-extract the N-oxide in the sample preparation so as to assure no contribution of artifactual products from DMAP N-oxide in the detection of the other compounds. For confirmation of the satisfactory separation of DMAP N-oxide from the others, the internal standards used for quantification were labeled with different numbers of deuterium atoms. Determination of unchanged DMAP was performed without any derivatization, that of DMAP N-oxide was carried out after conversion into trifluoroacetyl-MA by reaction with trifluoroacetic anhydride, and MA and AP were quantified after trifluoroacetyl-derivatization.After intraperitoneal administration of DMAP HCl to pigmented hairy rats (5 mg kg⁻¹ day⁻¹, 10 days, n=3), concentrations of DMAP and its metabolites in urine, plasma and hair were measured by GC–MS-SIM. The area under the concentration versus time curves (AUCs) of DMAP, DMAP N-oxide, MA and AP in the plasma were 397.2±97.5, 279.7±68.3, 18.4±1.2 and 15.9±2.2 μg min ml⁻¹, while their concentrations in the hair newly grown for 4 weeks after administration were 4.82±0.67. 0.45±0.09, 3.25±0.36 and 0.89±0.05 ng mg⁻¹, respectively. This fact suggested that the incorporation tendency of DMAP N-oxide from plasma into hair was distinctly low in comparison with the other compounds.     

Strong Relationship between Oral Dose and Tenofovir Hair Levels in a Randomized Trial: Hair as a Potential Adherence Measure for Pre-Exposure Prophylaxis (PrEP)

Background

Pre-exposure prophylaxis (PrEP) trials using tenofovir-based regimens have demonstrated that high levels of adherence are required to evaluate efficacy; the incorporation of objective biomarkers of adherence in trial design has been essential to interpretation, given the inaccuracy of self-report. Antiretroviral measurements in scalp hair have been useful as a marker of long-term exposure in the HIV treatment setting, and hair samples are relatively easy and inexpensive to collect, transport, and store for analysis. To evaluate the relationship between dose and tenofovir concentrations in hair, we examined the dose proportionality of tenofovir in hair in healthy, HIV-uninfected adults.

Methods

A phase I, crossover pharmacokinetic study was performed in 24 HIV-negative adults receiving directly-observed oral tenofovir tablets administered 2, 4, and 7 doses/week for 6 weeks, with a ≥3-week break between periods. Small samples of hair were collected after each six-week period and analyzed for tenofovir concentrations. Geometric-mean-ratios compared levels between each pair of dosing conditions. Intensive plasma pharmacokinetic studies were performed during the daily-dosing period to calculate areas-under-the-time-concentration curves (AUCs).

Results

Over 90% of doses were observed per protocol. Median tenofovir concentrations in hair increased monotonically with dose. A log-linear relationship was seen between dose and hair levels, with an estimated 76% (95% CI 60–93%) increase in hair level per 2-fold dose increase. Tenofovir plasma AUCs modestly predicted drug concentrations in hair.

Conclusions

This study found a strong linear relationship between frequency of dosing and tenofovir levels in scalp hair. The analysis of quantitative drug levels in hair has the potential to improve adherence measurement in the PrEP field and may be helpful in determining exposure thresholds for protection and explaining failures in PrEP trials. Hair measures for adherence monitoring may also facilitate adherence measurement in real-world settings and merit further investigation in upcoming PrEP implementation studies and programs.

Trial Registration

ClinicalTrials.gov +{"type":"clinical-trial","attrs":{"text":"NCT00903084","term_id":"NCT00903084"}}NCT00903084.     

Assaying progesterone,estradiol and cortisol concentrations in hair of Père David deer hinds: an alternative way to reflect seasonality of steroid secretion

The use of a hair hormone concentration assay is increasingly recognized as a useful and noninvasive technique for monitoring the endocrinological status of animals. However, few studies have focused on reproductive and stress hormones together. We used a chemiluminescent immunoassay to determine whether the progesterone, estradiol, and cortisol concentrations could be measured from hair and whether these hormone concentrations varied in different hair segments of captive Père David deer hinds. We found that progesterone, estradiol, and cortisol could be measured in the hair samples and that the progesterone concentration varied but the estradiol and cortisol concentrations did not among different hair segments. Contrary to the segmental decline in hair cortisol found in many studies, we found that progesterone concentration was higher near the tip than at the base of hair in Père David deer. This suggests that the variation in segmental hair steroid hormone concentration in seasonal molting animals may be mainly due to internal reproductive cycles and that hair steroid hormones may reflect long-term physiological changes and can thus be used for the conservation and management of wildlife.     

Direct determination of glucuronide and sulfate of p-hydroxymethamphetamine in methamphetamine users' urine

Two conjugates of p-hydroxymethamphetamine (p-OHMA), p-OHMA-glucuronide (p-OHMA-Glu) and p-OHMA-sulfate (p-OHMA-Sul) have been identified in methamphetamine (MA) users' urine by using liquid chromatography-high resolution tandem mass spectrometry (LC-HRMS-MS). The synthesis of p-OHMA-Glu and p-OHMA-Sul, and an LC-MS procedure for the simultaneous determination of MA and its four metabolites, amphetamine (AP), p-OHMA, p-OHMA-Glu and p-OHMA-Sul, in urine have also been established. After deproteinizing urine samples with methanol, LC-MS employing a C(18) semi-micro column with a gradient elution program provided the successful separations and MS determinations of these analytes within 20 min. Based on the established method, p-OHMA-Sul was detected at higher concentrations than p-OHMA-Glu in all of the three urine samples tested. These data suggest that sulfation is a major pathway in the MA phase II metabolism.     

Human immunodeficiency virus-1 Tat protein and methamphetamine interact synergistically to impair striatal dopaminergic function

The human immunodeficiency virus (HIV)-1 transactivating protein Tat may be pathogenically relevant in HIV-1-induced neuronal injury. The abuse of methamphetamine (MA), which is associated with behaviors that may transmit HIV-1, may damage dopaminergic afferents to the striatum. Since Tat and MA share common mechanisms of injury, we examined whether co-exposure to these toxins would lead to enhanced dopaminergic toxicity. Animals were treated with either saline, a threshold dose of MA, a threshold concentration of Tat injected directly into the striatum, or striatal injections of Tat followed by exposure to MA. Threshold was defined as the highest concentration of toxin that would not result in a significant loss of striatal dopamine levels. One week later, MA-treated animals demonstrated a 7% decline in striatal dopamine levels while Tat-treated animals showed an 8% reduction. Exposure to both MA + Tat caused an almost 65% reduction in striatal dopamine. This same treatment caused a 56% reduction in the binding capacity to the dopamine transporter. Using human fetal neurons, enhanced toxicity was also observed when cells were exposed to both Tat and MA. Mitochondrial membrane potential was disrupted and could be prevented by treatment with antioxidants. This study demonstrates that the HIV-1 'virotoxin' Tat enhances MA-induced striatal damage and suggests that HIV-1-infected individuals who abuse MA may be at increased risk of basal ganglia dysfunction.     

Hair analysis for drugs of abuse XIX. Determination of ephedrine and its homologs in rat hair and human hair

A sensitive GC-MS method was developed for the quantitative analysis of ephedrine (EP), phenylpropanolamine (PPA) and methylephedrine (ME) in animal and human hair. After washing with 0.1% sodium dodecyl sulfate, hair samples (10 mg) were added with deuterated internal standards, extracted by 1-h sonication and over night soaking in 2 ml of 5 M HCl-methanol (1:20) at room temperature. Following evaporation of the liquid phase, the residue was dissolved in phosphate buffer solution (pH 6.0) and purified using a solid-phase extraction procedure with Bond Elut Certify columns. Two types of derivatization were compared - using trifluoroacetic anhydride (TFAA) and pentafluoropropionic anhydride (PFPA) - for discrimination of EP and methamphetamine (MA). Derivatized extracts were analyzed by GC-MS in the EI mode using a capillary column (OV-1 equivalent). From the results comparing three GC-MS conditions, PFP-derivatives separated with a temperature gradient of 20°C/min from 60°C to 280°C gave the best resolution between EP and MA. ME was analyzed as a trimethylsilyl derivative using N,O-bis-trimethylsilyl acetamide at the above GC condition. The assay was linear from 0.5 to 50 ng/mg (r=0.998) and capable of detecting less than 50 pg of derivatized EP, PPA and ME on-column. Intra-assay precision was characterized by C.V. values from 5 to 16% in the concentration range of 1–10 ng/mg hair. The method was used for the quantitative determination of EP, PPA and ME in the hair obtained from three rats with dark brown hair after ten intraperitoneal injections (5 mg/kg/day) of the three drugs and from three male and one female volunteers with black hair after an oral dose of 50 mg/day of EP-HCl for three days. Hair samples were collected by shaving from the back of rats and cutting from the scalp of humans 28 days after the first dose. The incorporation rates of EP, PPA and ME into hair (the ratios of [hair concentration] to [AUC]) obtained from the animal experiment were 0.10, 0.07 and 0.03, respectively, which are a little lower than those (0.14, 0.10 and 0.04) of their desoxy-compounds, MA, amphetamine and dimethylamphetamine. EP was detected at an average of 2.25 ng/mg (n=4) in human scalp hair and at a range of 1–29 ng/mg (n=3) in human beard hair until day 14, but its metabolite (PPA) was at a trace level in the hair of the four subjects. The method was successfully used for detection of ME and EP in the hair of a neonate and its mother who was abusing Bron syrup containing ME during the pregnancy.     

Sensitivity to rewarding or aversive effects of methamphetamine determines methamphetamine intake

Amphetamines have rewarding and aversive effects. Relative sensitivity to these effects may be a better predictor of vulnerability to addiction than sensitivity to one of these effects alone. We tested this hypothesis in a dose-response study in a second replicate set of mouse lines selectively bred for high vs. low methamphetamine (MA) drinking (MADR). Replicate 2 high (MAHDR-2) and low (MALDR-2) MA drinking mice were bred based on MA consumption in a two-bottle choice procedure and examined for novel tastant drinking. Sensitivities to the rewarding and aversive effects of several doses of MA (0.5, 2 and 4 mg/kg) were measured using a place conditioning procedure. After conditioning, mice were tested in a drug-free and then drug-present state for time spent in the saline- and MA-paired contexts. Similar to the first set of MADR lines, by the end of selection, MAHDR-2 mice consumed about 6 mg MA/kg/18 h, compared to nearly no MA in MALDR-2 mice, but had similar taste preference ratios. MAHDR-2 mice exhibited place preference in both the drug-free and drug-present tests, and no significant place aversion. In contrast, MALDR-2 mice exhibited no place preference or aversion during the drug-free test, but robust place aversion in the drug-present test. These data extend our preliminary findings from the first set of MADR lines and support the hypothesis that the combination of greater sensitivity to the rewarding effects of MA and insensitivity to the aversive effects of MA is genetically associated with heightened risk for MA consumption.