In vivo proton magnetic resonance spectroscopy detection of human alcohol tolerance

Alcohol tolerance was ascertained with in vivo proton magnetic resonance spectroscopy (MRS) in men who regularly consumed either large (10-20 drinks/week) or small (2-4 drinks/weeks) amounts of beverage alcohol. Brain ethanol concentrations were determined by MRS, and blood ethanol levels were measured by gas chromatography after controlled ethanol administration (0.8 g/kg). Brain-blood ethanol concentration ratios for heavy drinkers were significantly greater than ratios for occasional drinkers (P < 0.002). Inasmuch as ethanol tolerance covaries with the severity of dependence, MRS procedures may facilitate our understanding of alcohol tolerance and treatment of alcoholism.

Effects of dopamine on prolactin: interactions with cocaine self-administration by female rhesus monkeys

The effects of dopamine on regulation of prolactin secretion were studied in female rhesus monkeys before cocaine exposure and again after 2 months to 2.7 years of daily cocaine self-administration. During chronic cocaine exposure, basal prolactin levels increased by 227 to 350% above drug-free control levels (P < .05). On each endocrine study day, three successive 80-min dopamine infusions (10 micrograms/kg/min i.v.) were alternated with 20-min interruptions of dopamine infusions to assess the degree of prolactin suppression and the magnitude of postdopamine prolactin increases. Dopamine significantly reduced prolactin below base-line levels within 60 to 80 min under all conditions (P < .05-.01). In four drug-naive follicular phase females, postdopamine increases in prolactin never exceeded predopamine base-line levels of 6.2 (+/- 1.8) ng/ml. After an average of 74 days of cocaine self-administration [3.7 (+/- 0.11) mg/kg/day], the postdopamine prolactin increases were significantly higher than during drug-free control conditions (P < .01) and reached hyperprolactinemic levels of 57.6 ng/ml. After an average of 300 days of cocaine self-administration [6.5 (+/- 0.06) mg/kg/day], postdopamine prolactin increases peaked at 339% above predopamine basal prolactin levels. After an average of 433 days of cocaine self-administration [6.45 (+/- 0.08) mg/kg/day] postdopamine prolactin increases remained significantly higher (P < .01) than during drug-free conditions. A similar pattern of postdopamine prolactin increases to hyperprolactinemic levels (ranging from 44.5 to 141.2 ng/ml) also were measured in two other females studied after 19 to 20 months of cocaine self-administration [6.21 (+/- 0.11) and 7.49 (+/- 0.17) mg/kg/day]. After 2.7 years of cocaine self-administration, one monkey developed persistent hyperprolactinemia and basal prolactin levels averaged 326 ng/ml after 89 days of cocaine abstinence. These data suggest that the prolactin secretory response to dopamine perturbation may provide a sensitive index of changes in dopaminergic regulation of prolactin during chronic cocaine exposure.

Cocaine effects on pulsatile secretion of ACTH in men

The effects of cocaine on pulsatile secretion of adrenocorticotropic hormone (ACTH) in men were studied under controlled clinical research ward conditions. Eight men with a Diagnostic and Statistical Manual of the American Psychiatric Association Version III, revised, diagnosis of concurrent cocaine and opioid dependence provided their informed consent for participation in this study. After an overnight fast, a challenge dose of cocaine (30 mg i.v.) or placebo was administered under single-blind conditions in a randomized order on 2 study days. Blood samples were collected at 2-min intervals for 76 min during base line and for an additional 76 min after i.v. administration of the challenge dose. Peak plasma cocaine levels of 313.8 +/- 46.5 ng/ml were detected within 2 min after cocaine administration. The cluster analysis program originally described by Veldhuis and Johnson (1986) was used to characterize ACTH pulsatile secretion (Iranmanesh et al., 1990). Acute cocaine administration (30 mg i.v.) significantly increased ACTH mean peak amplitude (P < .05), mean percent increase in peak amplitude, (P < .05), mean peak area (P < .04), total peak area (P < .04) and incremental peak height (P < .04). Mean ACTH valley levels (P < .02) and mean valley nadir (P < .02) were also significantly increased after cocaine administration. We postulate that cocaine stimulates the release of corticotropin releasing factor and that the cocaine-induced secretion of corticotropin releasing factor increases the amplitude of ACTH pulses, because ACTH pulse frequency was not altered by cocaine.

Buprenorphine effects on morphine- and cocaine-induced subjective responses by drug-dependent men

The effects of daily buprenorphine treatment (4 or 8 mg/day, sublingual) on reports of subjective effects after single intravenous doses of morphine (10 mg), cocaine (30 mg), and saline placebo were studied on an inpatient clinical research ward in 26 men concurrently dependent on opioids and cocaine (DSM-III-R). Latency to detection and certainty of a drug effect, as well as drug quality (intensity, euphoria, and dysphoria), were studied before and after 10 to 12 days of buprenorphine maintenance. Saline was accurately identified by all 26 patients during the drugfree baseline and by 25 patients during buprenorphine maintenance conditions. All patients accurately identified morphine during the drugfree period before treatment with buprenorphine, but 18 (69%) of 26 patients were unable to detect morphine during buprenorphine maintenance and 2 misidentified morphine as cocaine. Six men (23%) accurately identified morphine and reported that the intensity and quality of morphine's effects were equivalent to drugfree conditions. Cocaine levels in plasma 5 minutes after intravenous cocaine injection were equivalent before and during buprenorphine treatment and averaged 282.8 +/- 43.6 and 295.2 +/- 28.8 ng/ml during 4 and 8 mg/day of buprenorphine maintenance, respectively. All patients accurately identified cocaine before and during buprenorphine maintenance, and there were no significant changes in latency to detection and certainty of a drug effect or reports of cocaine-induced intensity or euphoria during buprenorphine treatment. The concordance between responses to morphine and cocaine during inpatient buprenorphine maintenance and drug use during the first 4 weeks of outpatient buprenorphine treatment was also examined in 16 men. The effects of buprenorphine on individual responses to an acute intravenous dose of morphine or cocaine during the inpatient study did not reliably predict the frequency of heroin or cocaine self-administration during the first 4 weeks of daily outpatient buprenorphine maintenance.

In vivo proton magnetic resonance spectroscopy of alcohol in rhesus monkey brain

Brain alcohol was measured in rhesus monkeys (Macaca mulatta) by proton magnetic resonance spectroscopy (MRS) following acute nasogastric alcohol administration (0.8 g/kg). Monkeys were anesthetized with ketamine and xylazine. A 1.5 T whole body imager and a 3-inch surface coil were used to acquire TE 30 and 270 ms spectra from a 7.5 cc voxel localized with a stimulated echo (STEAM) sequence. Venous blood samples were collected during spectral acquisitions for gas chromatographic determination of temporally concordant blood alcohol levels (BALs). Acute alcohol administration did not alter the resonance areas of N-acetylaspartate/N-acetyl containing compounds (NAA), choline containing compounds, or total creatine. The NAA resonance was used as an internal standard to calculate approximate brain alcohol concentrations, which averaged 27 +/- 3% and 27 +/- 8% of temporally concordant BALs (T2-corrected TE 30 and TE 270 ms spectra, respectively). In addition to reconfirming results from prior studies finding incomplete detection of brain alcohol with MRS, these results demonstrate the feasibility of measuring brain alcohol in anesthetized nonhuman primates to examine relationships between alcohol exposure history and MRS-visibility of brain alcohol.

Naltrexone-buprenorphine interactions: effects on cocaine self-administration

An opioid mixed agonist-antagonist analgesic, buprenorphine, significantly reduces cocaine self-administration by rhesus monkeys, but the relative contribution of buprenorphine's agonist and antagonist properties to this effect is unclear. This study examined the effects of concurrent treatment with naltrexone, a long-acting mu opioid antagonist, on buprenorphine's effects on cocaine and food self-administration by five rhesus monkeys. Cocaine (0.5 mg/kg per injection) and food self-administration (1 gm banana pellet) were maintained on a second order fixed ratio 4 (FR4) variable ratio (VR) 16:S schedule of reinforcement. Buprenorphine treatment alone (0.40 mg/kg/day) and in combination with ascending doses of naltrexone (0.05, 0.10, 0.20, and 0.40 mg/kg/day) was compared with naltrexone alone (0.40 mg/kg/day) and saline control treatment. Naltrexone was administered simultaneously or 20 minutes before buprenorphine administration. Each treatment condition was in effect for 10 days. Buprenorphine alone significantly reduced cocaine self-administration by an average of 53% in comparison to the saline treatment baseline (p < .01). When saline was substituted for buprenorphine, each monkey rapidly returned to its prebuprenorphine level of cocaine self-administration. Food self-administration in all conditions was equivalent to or significantly higher (p < .05) than food-maintained responding during the saline baseline. When buprenorphine and naltrexone were administered simultaneously, naltrexone significantly attenuated buprenorphine's suppressive effects on cocaine self-administration (p < .05 to .01). When naltrexone was administered 20 minutes before buprenorphine, there was a significant naltrexone dose-dependent (p < .01) decrease in buprenorphine's reduction of cocaine self-administration in comparison to the initial saline baseline. These data suggest that naltrexone antagonizes the partial mu agonist component of buprenorphine, which may be important for buprenorphine's effects on cocaine self-administration. Moreover, the addition of an opioid antagonist to reduce illicit diversion of buprenorphine might also compromise its effectiveness for treatment of dual dependence on cocaine and opiates.

Buprenorphine treatment of opiate and cocaine abuse: clinical and preclinical studies

Buprenorphine, an opioid mixed agonist-antagonist, is a potent analgesic that appears to be effective for the treatment of opiate abuse. Recent preclinical studies have shown that buprenorphine also significantly reduces cocaine self-administration by rhesus monkeys for periods up to 120 days. This unexpected finding has led to clinical trials to evaluate buprenorphine's effectiveness for the treatment of dependence on both cocaine and opiates, as defined by DSM-III-R criteria. Buprenorphine's safety in combination with cocaine and opiates and its effects on electroencephalographic sleep patterns and regional cerebral blood flow were evaluated during inpatient studies. Buprenorphine (4 or 8 mg/day given sublingually) did not accentuate the cardiovascular and respiratory changes induced by an acute challenge dose of cocaine (30 mg given intravenously) or morphine (10 mg given intravenously) alone. In an outpatient open trial, buprenorphine significantly reduced both opiate and cocaine abuse by patients who had abused these drugs for more than 10 years. Most of these patients had failed in other drug abuse treatment programs. Reports of needle sharing also decreased significantly, and no patient tested positive for human immunodeficiency virus (HIV). The apparent safety and effectiveness of buprenorphine, combined with a high level of patient acceptance, led the Food and Drug Administration to grant a compassionate extension of the approved period for outpatient buprenorphine treatment from 26 to 52 weeks. Clinical trials of buprenorphine are ongoing. Possible mechanisms underlying buprenorphine-cocaine interactions are now under investigation.

Acute effects of cocaine on anterior pituitary hormones in male and female rhesus monkeys

The effects of acute cocaine administration (0.4 or 0.8 mg/kg) on anterior pituitary hormones were studied in four male and six female adult rhesus monkeys during the midluteal phase of the menstrual cycle (days 20-23). Progesterone levels averaged 15.7 +/- 3 and 10.6 +/- 2.8 ng/ml before low and high dose cocaine administration. Integrated plasma samples were collected every 10 min for 40 min before i.v. administration of cocaine, and 11 postcocaine samples were collected over 110 min. Cocaine (0.8 mg/kg) stimulated a significant increase in luteinizing hormone (LH) within 10 to 20 min (P < .01) and LH reached peak levels (59-60% above base line) within 30 min after cocaine administration in both males and females. Plasma cocaine levels averaged 289 +/- 23 and 346 +/- 73 ng/ml at 10 min after i.v. cocaine (0.8 mg/kg) administration in males and females, respectively. Follicle stimulating hormone levels were unchanged in midluteal females. Male testosterone increased by 50% above average base-line levels 50 min after the LH peak (80 min postcocaine). These data are consistent with our previous findings that cocaine increased LH and enhanced luteinizing hormone-releasing hormone-stimulated LH in early follicular females. The low dose of cocaine did not change basal levels of LH and follicle stimulating hormone in midluteal females and both LH and testosterone were unaffected in males. Cocaine plasma levels averaged 97.6 +/- 29 and 68.3 +/- 9.1 ng/ml at 10 min after 0.4 mg/kg of cocaine in males and females, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Pituitary volume in men with concurrent heroin and cocaine dependence

Pituitary gland volume was measured in 16 men between the ages of 26-33 with magnetic resonance imaging. Eight male patients had a Diagnostic and Statistical Manual III-Revised, American Psychiatric Association Axis I diagnosis of concurrent opioid and cocaine dependence. The average duration of opioid and cocaine abuse was 7.8 +/- 2.0 and 6.9 +/- 1.4 yr, respectively. All patients were in good physical health as determined by physical examination, blood chemistry, hemogram and hormone analysis, and all tested negatively for the HIV antibody. No patient had any other Diagnostic and Statistical Manual III-Revised Axis I diagnosis or neurological disorder. Eight healthy males served as age-matched control subjects. None of the control subjects had any past or current history of substance abuse or any clinical indication for magnetic resonance imaging. Opioid and cocaine dependent men had significantly larger pituitary gland volumes (730.0 +/- 24.4 mm3) than control subjects (540.0 +/- 26.6 mm3) (P < 0.01). The significant increase in pituitary gland volume in men who abuse opiates and cocaine may be antecedent to detection of abnormal anterior pituitary hormone function.

Regional cerebral blood flow improves with treatment in chronic cocaine polydrug users

Brain perfusion is abnormal in chronic cocaine users. To determine whether these perfusion abnormalities are reversible following treatment, we studied 10 cocaine-dependent polydrug users with 99mTc-HMPAO SPECT 2 to 3 days after admission to an inpatient treatment facility and at 7 to 8 days and 17 to 29 days after abstinence from drugs. The patients also received buprenorphine, an opioid mixed agonist-antagonist, beginning 10 days after admission and continuing to the end of the study. Imaging began 10-15 min after injection of 99mTc-HMPAO (20 mCi) using an annular gamma camera system. MRI was performed during hospitalization using a 1.5 Tesla system. SPECT and MRI were merged and five axial SPECT slices centered at the level of the basal ganglia were selected for analysis. Activity ratios were derived for cortical regions relative to cerebellar activity and were corrected for linearity with respect to regional cerebral blood flow. The cortical regions were classified as abnormal (activity ratio < 0.6), borderline (0.6-0.72) and normal (> 0.72) based on the results of the first SPECT study. In abnormal zones, regional cerebral blood flow (rCBF) increased 11.0% +/- 9.0% at 7 to 8 days and 23.8% +/- 9.4% at 17 to 29 days after initiation of treatment. The increase in rCBF was 4.8% +/- 7.1% (7 to 8 days) and 11.1% +/- 8.0% (17 to 29 days) in borderline cortex and decreased 2.9% +/- 6.3% (7 to 8 days) and increased only 2.7% +/- 13.4% (17 to 29 days) in normal cortex. The increase in rCBF did not vary significantly by location. The perfusion defects observed in chronic cocaine polydrug users are partially reversible with short-term abstinence and buprenorphine treatment.

Acute interactions of buprenorphine with intravenous cocaine and morphine: an investigational new drug phase I safety evaluation

Recent preclinical and clinical studies suggest that buprenorphine, an opioid mixed agonist-antagonist, may be useful for the treatment of dual dependence on cocaine and opiates. This report describes an inpatient clinical evaluation of the safety of buprenorphine alone and in combination with single doses of cocaine and morphine. Twenty subjects with a DSM-III-R diagnosis of concurrent cocaine and opioid dependence were randomly assigned to maintenance treatment with single daily doses of 4 or 8 mg of sublingual buprenorphine for 21 days. Side effects and vital signs were evaluated every day once every 8 hours and for 2 hours after daily buprenorphine administration. The physiologic effects of a single-blind challenge dose of cocaine (30 mg intravenously), morphine (10 mg intravenously), and intravenous saline placebo were measured before and during buprenorphine maintenance. Before buprenorphine maintenance, subjects underwent methadone detoxification followed by a 9-day drug-free period. Three baseline single-blind challenge dose studies were conducted on study days 7, 8, and 9 during the drug-free period. Cardiovascular responses to cocaine and to morphine were equivalent under drug-free and buprenorphine maintenance conditions. Respiration and temperature changes in response to cocaine were also equivalent before and during buprenorphine maintenance. Respiratory rates were slightly lower after morphine administration during maintenance on 8 mg of buprenorphine, but this was not statistically significant. Mild opioid agonist-like side effects were reported during buprenorphine induction and maintenance. These included headache, sedation, nasal discharge, abdominal discomfort, and anxiety. Most opioid agonist side effects decreased within 12 to 14 days. An electrocardiogram and blood chemistry measures were normal before and during buprenorphine maintenance. These data suggest that daily maintenance on buprenorphine is not associated with adverse side effects or toxic interactions with a single acute dose of intravenous cocaine or morphine.

Effects of intermittent buprenorphine administration on cocaine self-administration by rhesus monkeys

In previous studies, daily buprenorphine administration significantly reduced cocaine self-administration by rhesus monkeys over 15 to 120 days (Mello et al., 1990, 1992). This report describes the effects of 60 days of intermittent buprenorphine (0.40 mg/kg) treatment once every 48 hr or 72 hr on cocaine and food self-administration by six rhesus monkeys. Cocaine (0.05 or 0.10 mg/kg/injection) and food (1-g banana pellet) self-administration were maintained on a fixed ratio 4, (variable ratio 16:S) reinforcement schedule. Intermittent buprenorphine treatment reduced cocaine self-administration significantly below saline treatment levels (P < .01). On the first day of buprenorphine treatment, cocaine self-administration averaged 53 and 60% below base line (P < .01-.0001). Cocaine self-administration remained significantly below base line on day 2 (P < .02-.0001) but usually returned to base-line levels by day 3. During buprenorphine treatment once every 48 hr, cocaine self-administration gradually increased over time in four monkeys (P < .001-.0005). These data suggest that intermittent buprenorphine treatment is less effective than daily buprenorphine treatment in reducing cocaine self-administration by rhesus monkeys. Food self-administration decreased by 23.6 and 12.7% from the saline base line during buprenorphine treatment every 48 and 72 hr, respectively. On the day of buprenorphine treatment, food self-administration was usually significantly lower than during the saline base line (P < .05-.0001), but usually returned to or exceeded base line levels by days 2 and 3. There were no significant changes in food self-administration over time with intermittent buprenorphine treatment every 48 hr.

The effects of nalbuphine and butorphanol treatment on cocaine and food self-administration by rhesus monkeys

This study was designed to determine whether opioid mixed agonist-antagonist analgesics other than buprenorphine also selectively reduce cocaine self-administration by rhesus monkeys. The effects of daily treatment with nalbuphine (0.1 to 3 mg/kg/day) or (0.254 to 7.62 mumol/kg/day), butorphanol (0.01 to 0.3 mg/kg/day) or (0.0209 to 0.628 mumol/kg/day), and saline on cocaine and food self-administration were each studied for 40 sessions over 10 consecutive days. Cocaine (0.05 or 0.10 mg/kg/inj) and food (1-gm banana pellets) self-administration were maintained on a fixed ratio 4 (variable ratio 16:S) schedule of reinforcement. Both nalbuphine and butorphanol reduced cocaine self-administration (p < 0.0001) but this effect was not selective since food self-administration also decreased in a dose-dependent manner (p < 0.0001). Nalbuphine administration (1 to 3 mg/kg/day) decreased cocaine injections to 40% to 60% below baseline (p < 0.01) and food pellets 30% to 68% below baseline (p < 0.01). Lower doses of nalbuphine (0.10 and 0.30 mg/kg) did not change cocaine- or food-maintained responding significantly. All doses of butorphanol (0.01 to 0.3 mg/kg/day) reduced cocaine injections to 16% to 58% below baseline (p < 0.01). Food self-administration decreased to 21% to 70% below baseline (p < 0.01) at butorphanol doses of 0.03 to 0.3 mg/kg/day). These data suggest that these opioid mixed agonist-antagonist analgesics may not be useful as pharmacotherapies for the treatment of cocaine abuse.

Effects of alcohol on E2 beta-stimulated luteinizing hormone in ovariectomized rhesus monkeys

Anovulation is a frequent concomitant of alcohol abuse, but it has been difficult to assess the acute effects of alcohol on ovulation. Estradiol benzoate (E2 beta) can stimulate a luteinizing hormone (LH) surge in ovariectomized monkeys that appears to be associated with increased luteinizing hormone-releasing hormone (LHRH) pulse frequency and amplitude. The acute effects of alcohol (2.5 and 3.5 g/kg) and an isocaloric sucrose control solution on LH and follicle-stimulating hormone (FSH) secretory activity were studied in five ovariectomized monkeys 41 to 51 hours after administration of E2 beta (42 micrograms/kg, IM). Integrated plasma samples were collected at 20-minute intervals over 10 hours. Under sucrose control conditions, LH increased to 445 and 584 ng/ml within 46 to 49.3 hours after E2 beta administration in two monkeys and high-amplitude LH pulses were evident in three monkeys. Alcohol (2.5 and 3.5 g/kg) significantly decreased the number of LH peaks and valleys (p < 0.01). Peak blood alcohol levels averaged 195 and 291 mg/dl. After 2.5 g/kg alcohol, there was no LH surge or LH pulses in four of five monkeys. A delayed LH surge occurred in one monkey 48 to 50.6 hours after E2 beta when blood alcohol levels decreased to 62 mg/dl. After 3.5 g/kg alcohol, no monkey had an LH surge and pulsatile LH release was significantly reduced in comparison to control conditions (p < 0.01). FSH levels remained stable across alcohol and control conditions. These data suggest that alcohol attenuates pituitary release of LH in response to E2 beta stimulation. These findings are consistent with menstrual cycle disruptions observed in alcohol-dependent women, social drinkers, and in a primate model of alcoholism.

Acute effects of cocaine on plasma adrenocorticotropic hormone, luteinizing hormone and prolactin levels in cocaine-dependent men

Acute cocaine administration alters secretion of anterior pituitary hormones in experimental animals, and cocaine abuse may compromise neuroendocrine function in humans. The goal of this study was to examine cocaine's acute effects on neuroendocrine hormones in cocaine-dependent men. Plasma adrenocorticotropic hormone (ACTH), luteinizing hormone and prolactin levels were measured in 18 men before and after i.v. administration of cocaine (30 mg) or placebo. Each subject served as his own control during the i.v. placebo and cocaine administration conditions. Plasma cocaine levels peaked at 260 ng/ml within 5 min after the i.v. injection. Plasma ACTH levels increased significantly above base-line levels at 5, 15, 30 (P < .01) and 45 min (P < .05) after i.v. cocaine. Plasma luteinizing hormone levels increased significantly above base-line levels at 5 (P < .05) and at 15 min (P < .01) after i.v. cocaine. No changes in plasma ACTH or luteinizing hormone levels were found after i.v. placebo injection. Plasma prolactin levels decreased significantly at 30, 45, 60, 90 and 120 min (P < .01) after both i.v. cocaine and placebo administration. Cocaine-induced increases in plasma ACTH levels may be due to its effects on dopaminergic systems which modulate corticotropin-releasing factor release in brain.

Buprenorphine attenuates the effects of cocaine on adrenocorticotropin (ACTH) secretion and mood states in man

Adrenocorticotropin (ACTH) levels in plasma increased rapidly to 105% above baseline within 5 minutes after intravenous injection of cocaine (30 mg) in cocaine-dependent men. The time course of ACTH stimulation paralleled increases in plasma cocaine levels and self-reports of salient drug effects on mood states and did not occur after placebo administration. An opioid mixed agonist-antagonist, buprenorphine (4 mg/day sublingually), suppressed the acute cocaine-induced stimulation of both ACTH and euphoria. Buprenorphine's suppression of postcocaine ACTH and euphoria were not related to differences in plasma cocaine levels or cocaine-induced alterations of cardiovascular function.

The effects of chronic buprenorphine treatment on cocaine and food self-administration by rhesus monkeys

The goal of this study was to determine if buprenorphine continues to reduce cocaine self-administration over long periods of treatment, or if tolerance develops to this effect. The effects of 30 to 120 days of buprenorphine treatment (0.32 mg/kg/day) on cocaine and food self-administration were examined in six rhesus monkeys. Saline control treatment was studied for 15 days before and after buprenorphine treatment. Intravenous cocaine (0.05 or 0.10 mg/kg) and food (1 g banana pellet) self-administration were maintained on a FR 4 (VR 16:S) schedule of reinforcement. Cocaine self-administration decreased significantly (P less than .0001) and remained 60 to 97% below saline treatment baseline levels (52 +/- 2 injections/day) throughout 120 days of buprenorphine treatment (P less than .01). After substitution of saline for buprenorphine, cocaine self-administration resumed and averaged between 21 (+/- 3.6) and 56 (+/- 6.5) injections per day over 20 days. Buprenorphine plasma levels averaged 18 (+/- 2.84) ng/ml (range 10.9-30 ng/ml) during buprenorphine treatment. Buprenorphine plasma levels usually decreased by 50% or more within 27 hr after the last buprenorphine dose. Low levels of buprenorphine (0.10-0.19 ng/ml) were measured for 30 to 74 days after abrupt termination of daily buprenorphine treatment. Food self-administration was initially reduced (P less than .01-.05), but tolerance to buprenorphine's suppression of food-maintained responding developed over 30 to 70 days of treatment. Food self-administration returned to and significantly exceeded (P less than .05-.01) saline treatment base-line levels, whereas cocaine self-administration remained significantly suppressed.(ABSTRACT TRUNCATED AT 250 WORDS)

Hyperprolactinemia and macrocytosis in women with alcohol and polysubstance dependence

Chronic alcoholism and drug abuse are often associated in women with derangements of reproductive function such as amenorrhea, anovulation, luteal phase dysfunction and early menopause. Endocrine profiles were studied of the first 18 women (aged 17-58) admitted consecutively to a Massachusetts hospital for treatment of alcohol/polysubstance dependence under civil commitment. Twelve women were diagnosed as alcohol dependent according to criteria established in DSM-III-R. Their daily alcohol consumption ranged from 42-324 grams. Six women were diagnosed as polysubstance dependent. In addition to alcohol (84-831 g/day), cocaine was the most frequently abused drug followed by tranquilizers, marijuana and opiates. Over 60% of alcohol-dependent women of reproductive age had either hyperprolactinemia or macrocytosis (increased mean corpuscular volume, MCV), or both. Over 60% of the polysubstance-dependent women of reproductive age had either hyperprolactinemia or increased MCV. Over 80% of alcohol-dependent women of postmenopausal age had either hyperprolactinemia or increased MCV, or both. We conclude that evaluation of plasma prolactin levels and MCV may be useful as biological state markers for alcoholism and polysubstance abuse in women.

Brain ventricular size in female alcoholics: an MRI study

The brains of ten alcohol-dependent women between the ages of 21 and 65 were studied with Magnetic Resonance Imaging (MRI) techniques. All women had MRI scans twice during the withdrawal period. Only one of the ten women had abnormally enlarged ventricles. At the time of the second scan there were no significant changes in ventricular size from the first scan. No correlations were found between age and ventricular size, or years of alcohol abuse and ventricular size.

Cocaine effects on luteinizing hormone-releasing hormone-stimulated anterior pituitary hormones in female rhesus monkey

The effects of acute cocaine administration on synthetic LHRH-stimulated anterior pituitary hormones (LH, FSH, and PRL) were studied in 6 female rhesus monkeys during the follicular phase of the menstrual cycle (days 4-7). Integrated plasma samples were collected every 10 min for 40 min before iv administration of cocaine (0.4 or 0.8 mg/kg) or an equal volume of vehicle control solution. Synthetic LHRH (100 micrograms, iv) was administered 10 min after cocaine or placebo-cocaine administration, and 10 plasma samples were collected for an additional 100 min. LHRH stimulated a significant increase in LH within 10 min after placebo-cocaine administration (P less than 0.05) and after each dose of cocaine (P less than 0.0001). Cocaine (0.4 mg/kg) significantly enhanced LHRH stimulation of LH compared to placebo or 0.8 mg/kg cocaine administration (P less than 0.01). FSH increased significantly within 20-30 min after LHRH alone (P less than 0.008) and after 0.4 mg/kg cocaine (P less than 0.0001). LHRH-stimulated FSH levels also were significantly higher after 0.4 mg/kg cocaine than after placebo or 0.8 mg/kg cocaine (P less than 0.01). These data indicate that cocaine does not suppress LHRH stimulation of pituitary gonadotropins, and low doses of cocaine significantly enhance LH and FSH release. Consequently, cocaine does not compromise anterior-pituitary function at the level of the gonadotroph and may stimulate hypothalamic release of endogenous LHRH. PRL levels were unchanged by LHRH and placebo-cocaine administration. After LHRH and cocaine administration, PRL levels decreased significantly (P less than 0.05-0.01) and remained suppressed throughout the 110-min postcocaine sampling period. These data indicate that cocaine's significant suppression of PRL is not blocked by LHRH. These findings are consistent with dopaminergic inhibitory control of PRL and suggest that cocaine's inhibition of dopamine reuptake down-regulates pituitary lactotroph activity in rhesus monkey.

Desipramine effects on cocaine self-administration by rhesus monkeys

The effects of desipramine treatment (0.56-10.0 mg/kg per day) on cocaine self-administration were compared to saline treatment in five rhesus monkeys. Cocaine (0.050 or 0.100 mg/kg per inj) and food (1 g banana pellets) self-administration were maintained on an FR 4 (VR 16:S) reinforcement schedule. Desipramine (or an equal volume saline control solution) was infused over 1 h each day through the second lumen of an intravenous catheter. After 5 days of baseline saline treatment, seven doses of desipramine each were administered for 5 days in an ascending order. Cocaine self-administration increased (P less than 0.01) or remained equivalent to base-line levels in 4 of 5 subjects during the first 15 days of desipramine treatment (0.56 to 1.78 mg/kg per day). Three monkeys continued to self-administer cocaine equivalent to or significantly above base-line levels (P less than 0.01) during days 16-30 of desipramine treatment (3.2-7.86 mg/kg per day). The highest desipramine dose (10 mg/kg per day) significantly suppressed cocaine self-administration in only one of these three monkeys (P less than 0.01). Desipramine treatment (3.2-10.0 mg/kg per day) suppressed cocaine self-administration (P less than 0.01) without a concomitant suppression of food-maintained responding in one of five subjects. A generalized suppression of both cocaine and food-maintained responding (P less than 0.01) during desipramine treatment occurred in one monkey that took the highest base-line levels of cocaine (6.3 +/- 1.03 mg/kg per day). Food-maintained responding remained equivalent to or significantly above (P less than 0.01) base-line levels in four of five monkeys during desipramine treatment. A transient decrease in food self-administration at desipramine doses of 1.78-5.62 mg/kg per day occurred in one monkey (P less than 0.01). Thirty days of desipramine treatment at the highest doses (5.62, 7.86 and 10.0 mg/kg per day for 10 days each) also did not suppress cocaine self-administration in a monkey that took an average of 4 mg/kg per day of cocaine during saline base-line treatment. These primate data are concordant with the extant clinical literature on the inconsistent effects of desipramine treatment; i.e., both stimulation of cocaine use and inconsistent or incomplete attenuation of cocaine abuse during desipramine maintenance have been reported.

Acute effects of cocaine on prolactin and gonadotropins in female rhesus monkey during the follicular phase of the menstrual cycle

The acute effects of i.v. cocaine on basal levels of prolactin (PRL), luteinizing hormone (LH) and follicle-stimulating hormone were examined in nine female rhesus monkeys during the early follicular phase of the menstrual cycle (days 4-7). Integrated plasma samples were collected at 10-min intervals for 40 min before and 110 min after administration of cocaine (0.4 and 0.8 mg/kg i.v.). Cocaine plasma levels averaged 105 +/- 19 and 157 +/- 23 ng/ml after low- and high-dose administration. PRL decreased significantly (P less than .01) after cocaine administration and reached a nadir within 60 to 70 min. Inasmuch as cocaine blocks dopamine reuptake, PRL suppression is consistent with dopaminergic inhibitory control of PRL release from the pituitary. However, cocaine's effects on PRL were biphasic in 10 of 18 studies. PRL increased within 90 to 110 min post-cocaine and sometimes exceeded base-line levels by over 100%. The duration of PRL suppression (80 min) and the time of onset of the subsequent rebound PRL increase corresponds to the estimated half-life of i.v. cocaine in monkey plasma. PRL suppression followed by a rebound elevation also is consistent with clinical reports of hyperprolactinemia in chronic cocaine abusers. LH increased significantly (P less than .01) within 20 min after cocaine administration and remained above base-line for 40 to 50 min. Follicle-stimulating hormone did not change significantly after cocaine administration. Cocaine's stimulation of LH is consistent with cocaine's alleged enhancement of sexual arousal.(ABSTRACT TRUNCATED AT 250 WORDS)

In vivo proton magnetic resonance spectroscopy of alcohol in human brain

The covariance between blood and brain alcohol levels and subjective reports of mood were examined in 6 healthy adult men after consumption of 0.7 g/kg of beverage alcohol. There was significant (p less than 0.01) temporal concordance between ascending and peak blood alcohol levels and regional brain alcohol levels as measured by in vivo proton Magnetic Resonance Spectroscopy (MRS) when N-acetyl aspartate (N-AA) concentration was used as an internal standard. The frequency of reports of both euphoria and dysphoria also paralleled the ascending limb of the blood and brain alcohol curve. However, peak blood alcohol levels were higher (125.67 +/- 10.91 mg/dl) and earlier (35 min postdrinking) than peak brain alcohol levels (26.25 +/- 6.38 mg/dl) detected 50 min after alcohol intake. This difference in brain and blood alcohol levels appears to be associated with the echo time (TE) parameters of the MRS. A decrease in TE from 270 msec to 50 msec resulted in a marked increase in brain alcohol detectability. MRS measures will permit analysis of regional differences in brain alcohol concentrations and covariance with behavioral, neurophysiologic and neuroendocrine concomitants of acute alcohol intoxication in man.

Buprenorphine and naltrexone effects on cocaine self-administration by rhesus monkeys

The effects of daily treatment with buprenorphine (0.237-0.70 mg/kg/day), naltrexone (0.32-3.20 mg/kg/day) and saline on cocaine self-administration were compared in rhesus monkeys. Cocaine (0.05 or 0.10 mg/kg/injection) and food (1-g banana pellets) self-administration were maintained on a fixed-ratio 4 (variable ratio 16:S) schedule of reinforcement. Buprenorphine, naltrexone or an equal volume saline control solution were infused slowly over 1 hr through one lumen of a double lumen i.v. catheter at the same time each day. Saline and each dose of buprenorphine (0.237, 0.40 and 0.70 mg/kg/day) or naltrexone (0.32 and 3.20 mg/kg/day) were studied for 60 sessions over 15 consecutive days. Buprenorphine significantly suppressed cocaine self-administration (P less than .001-.0001) in comparison to saline in all monkeys. Cocaine self-administration decreased by 49 to 95% in five of six monkeys on the 1st day of buprenorphine administration (0.237 and 0.40 mg/kg/day) and remained suppressed by an average of 72 to 93% during buprenorphine treatment. After abrupt termination of buprenorphine treatment (0.237 and 0.70 mg/kg/day), cocaine self-administration remained suppressed for an average of 16 +/- 4.4 and 28 +/- 6.6 days, respectively. Buprenorphine (0.237 and 0.40 mg/kg/day) initially suppressed food self-administration in some monkeys (P less than .01), but tolerance developed to buprenorphine's effects on food-maintained responding whereas cocaine self-administration remained significantly suppressed. During treatment with 0.70 mg/kg/day of buprenorphine, food self-administration returned to or significantly exceeded (P less than .01) base-line levels in three animals. Daily patterns of food self-administration were not disrupted by buprenorphine treatment. Naltrexone (0.32 mg/kg/day) initially suppressed cocaine self-administration by an average of 28% over 15 days (P less than .0009). During high-dose naltrexone treatment (3.20 mg/kg/day), cocaine-maintained responding was suppressed by 25% over 15 days (P less than .01). Cocaine-maintained responding was not significantly changed by naltrexone in one of the five subjects. Food self-administration decreased by 24% (P less than .05) after 5 days of 0.32 mg/kg of naltrexone administration, then exceeded baseline levels during 3.20 mg/kg of naltrexone administration. These data suggest that buprenorphine decreases cocaine's reinforcing properties more effectively than naltrexone across the dose-range studied. Buprenorphine may be an effective pharmacotherapy for treatment of cocaine abuse as well as dual abuse of cocaine plus heroin.