Fat-mobilizing action of amphetamine

Serum Metabolomic Analysis of Male Patients with Cannabis or Amphetamine Use Disorder

Studies have demonstrated that chronic consumption of abused drugs induces alterations in several proteins that regulate metabolism. For instance, methamphetamine exposure reduces glucose levels. Fatty and amino acid levels were altered in groups exposed to abused drugs. Therefore, in our study, we investigated the serum metabolomic profile of patients diagnosed with cannabis and/or amphetamine use disorders. Blood was obtained from subjects (control, amphetamine, and cannabis). Detection of serum metabolites was performed using gas chromatography. The ratio peak areas for metabolites were analyzed across the three groups. Both cannabis and amphetamine groups showed higher d-erythrotetrafuranose, octadecanoic acid, hexadecenoic acid, trans-9-octadecanoic acid, lactic acid and methyl thio hydantoin metabolites compared with the control group. Moreover, cannabis patients were found to possess higher glycine, 9,12 octadecanoic acid malonic acid, phosphoric acid and prostaglandin F1a than controls. Our analysis showed that the identified metabolic profile of cannabis or amphetamine use disorder patients was different than control group. Our data indicated that chronic exposure to cannabis or amphetamine dysregulated metabolites in the serum. Future studies are warranted to explore the effects of these abused drugs on the metabolic proteins.

The effects of the prodrug Vyvanse on spatial working memory and adiposity in rats

The present study investigated the influence of Vyvanse (lisdexamfetamine), a psychomotor stimulant, on spatial working memory, body weight, and adiposity in rats. Control and experimental rats were placed in individual cages equipped with a running wheel, and food and water were provided ad-libitum. The study was divided into three periods: 1) habituation, 2) experimental, and 3) withdrawal. Control rats received a placebo in periods 1, 2 and 3, while experimental rats received a placebo in periods 1 and 3. Experimental rats received a treatment of Vyvanse in place of the placebo during period 2. Spatial working memory was examined by utilizing the methodology of the Morris Water Maze. Rats were evaluated by performance in the maze each day during the experimental and withdrawal periods. Each assessment consisted of two trials. The first was a sample trial in which an escape platform was discovered by trial and error. The second was a test trial in which the platform location was recalled using working memory. Platform placement and start location of the rats were changed every session. It was hypothesized that Vyvanse would effectively enhance spatial working memory, and significantly decrease body weight and adiposity without side effects on activity level and anxiety in rats. Results supported the hypothesis. Compared to control rats, Vyvanse treated rats had significant improvement in working memory and significantly lowered body weight, as well as significantly decreased mesenteric, renal, and epididymal adiposity. No significant effects on activity level and task specific anxiety were noted in experimental animals. When compared to placebo treatment, Vyvanse treatment produced no significant influence on food and water intake. It was concluded that Vyvanse treatment in rats can enhance spatial working memory, and decrease adiposity without suppressing normal appetite.

Effect of methamphetamine on the fasting blood glucose in methamphetamine abusers

Methamphetamine is a popular psychostimulant worldwide which causes neurotoxicity and neuroinflammation. Although previous studies have characterized potential associations between addictive drugs and fasting blood glucose, the influence of methamphetamine on the blood glucose is still largely unknown. The present study was designed to investigate the change of fasting blood glucose of methamphetamine abusers and to confirm the impairment of liver and kidney. Fasting blood glucose was significantly decreased in methamphetamine abusers and in a high-fat diet mouse model with methamphetamine treatment discontinuation. Serum level of ALT, creatine kinase and creatinine were increased in methamphetamine abusers. Serum level of ALT and AST were increased in a high-fat diet mouse model after methamphetamine injection, but there was no significant difference in the anatomy of the liver and kidney in high-fat diet treated mice with or without methamphetamine. The levels of ALT and creatinine were also increased in the methamphetamine abusers. This study demonstrated that the level of glucose was decreased in methamphetamine abusers and in high-fat diet-fed mice after methamphetamine treatment discontinuation. The effect of methamphetamine on the levels of blood glucose may provide the evidence that methamphetamine abusers should be keep energy balance due to the low blood glucose.

Exposure to Amphetamines Leads to Development of Amphetamine Type Stimulants Associated Cardiomyopathy (ATSAC)

With rapidly rising prevalence of exposure to Amphetamine Type Stimulants (ATS), novel insights into cardiotoxic effects of this substance are being presented in the literature and remarkably ATS Associated Cardiomyopathy (ATSAC) is emerging as a novel cardiovascular condition with its distinctive pathogenesis, risk factors, clinical features and prognosis. A comprehensive systematic review was performed to explore and analyze the current evidence on the association between ATS exposure and development of cardiomyopathy, biological mechanisms involved in pathogenesis of ATSAC, risk factors, clinical features and course of patients with ATSAC. Several animal studies, case reports, case series and case-control studies support the association between ATS exposure and ATSAC. Oxidative stress, accelerated apoptosis, increased p53 activity, cardiomyocyte necrosis, perfusion defects, fatty acid toxicity, altered gene expression, abnormal cardiac protein synthesis and function in addition to defects in intracellular calcium hemostasis present themselves as likely mechanisms of cardiotoxicity in ATSAC. Majority of patients with ATSAC were found to be male, young and presented late with severe dilated cardiomyopathy. Female ATS users predominantly develop Takotsubo type of ATSAC and in particular its atypical basal variant. Overall, cessation of ATS exposure seems to be associated with some degree of reversibility and recovery in ATSAC sufferers.

Drugs and sport. Research findings and limitations

Many types of drugs are used by athletes to improve performance. This paper reviews the literature on 3 categories of drugs: those that enhance performance as stimulants (amphetamines, ephedrine, and cocaine), those that are used to reduce tremor and heart rate (beta-blockers) and those involved in bodyweight gain or loss (anabolic-androgenic steroids, growth hormone, beta 2-agonists, and diuretics). Limitations of research on these drugs as they relate to performance enhancement are also discussed. The numerous studies that have assessed the effects of amphetamines on performance report equivocal results. This may be due to the large interindividual variability in the response to the drug and the small sample sizes used. Most studies, however, show that some individuals do improve exercise performance when taking amphetamines, which may be attributed to their role in masking fatigue. As a stimulant, ephedrine has not been found to improve performance in the few studies available. More recently, ephedrine has been purported to be effective as a fat burner and used by athletes to maintain or improve muscle mass. Although research on individuals with obesity supports the use of ephedrine for fat loss, no studies have been done on athletes. The few studies of cocaine and exercise suggest that little to no performance gains are incurred from cocaine use. Moreover, the sense of euphoria may provide the illusion of better performance when, in actuality, performance was not improved or was impaired. beta-Blockers have been found to reduce heart rate and tremor and to improve performance in sports that are not physiologically challenging but require accuracy (e.g. pistol shooting). However, there is evidence that some individuals may be high responders to beta-blockers to the extent that their heart rate response is so blunted as to impair performance. Although equivocal, several studies have reported that anabolic-androgenic steroids increase muscle size and strength. However, most studies are not well controlled and use insufficient drug doses. One recent well controlled study did find an increase in muscle mass and strength with supraphysiological doses, and the improvements were greater in participants who were also resistance training. There is little information available on the effects of growth hormone on muscle mass or performance in athletes, although data suggest that growth hormone administration does not increase muscle protein synthesis. beta 2-Agonists, such as clenbuterol and salbutamol, when administered orally appear to improve muscular strength due to their potential role in increasing muscle mass. However, studies have not been done using athletes. Diuretics results in a loss of body water and hence bodyweight that can be advantageous for sports with strict bodyweight classifications. There is insufficient evidence on possible performance decrements in the field that could result from dehydration induced by the diuretics. Overall, the most significant concern in studies of drug use is the large inter-individual variability in responses to a drug. Further studies are needed to understand why some individuals are more responsive than others and to assess whether the responses are consistent for a given individual. Most studies of drug effectiveness have not used athletes. The effectiveness of many drugs may be reduced in highly trained athletes because there is a lower margin for improvement.

Differential effects of amphetamine and fenfluramine on dietary self-selection in rats

Daily caloric intakes and dietary self-selection of the three macronutrients, protein, fat and carbohydrate were examined in female rats following administration of d-amphetamine sulfate (0.0, 0.5, 1.0 and 2.0 mg/kg, IP) or fenfluramine hydrochloride (0.0, 1.5, 3.0 and 6.0 mg/kg, IP). Animals were maintained on ground Purina Chow or one of two self-selection regimes, one with a high-caloric fat ration (7.85 kcal/g) and the other with a fat ration isocaloric to the carbohydrate and protein rations (3.76 kcal/g). Animals received drug injections at the beginning of a daily 8-hour feeding period with nutrient intakes measured at 2, 4 and 8 hrs following injections. While both amphetamine and fenfluramine lef to dose-related decreases in total caloric intakes, the two drugs resulted in different temporal patterns of feeding. Amphetamine produced its greatest effect on caloric intake during the first 2 hours of the feeding period, whereas fenfluramine suppressed caloric intake equivalently across the 8-hour feeding period. The two anorectic drugs also led to different patterns of nutrient choice. When animals were given the high-caloric fat ration, amphetamine selectively decreased fat intake while fenfluramine produced decreases in both protein and fat intakes, sparing carbohydrate intake. In contrast, when animals were given the isocaloric fat ration, amphetamine resulted in a general suppression of nutrient intakes while fenfluramine led to a sustained decrease in fat intake with a relative sparing of protein and carbohydrate consumption.

Swimming capacity of mice after prolonged treatment with psychostimulants. II. Effect of methamphetamine on swimming performance and availability of metabolic substrates

Swimming endurance and availability of metabolic substrates (blood glucose and nonesterified fatty acids [NEFA], liver and muscle glycogen, body fat) were studied in mice treated with 10 microgram/g methamphetamine/day for 6 weeks. At the end of the 6-week treatment, motor coordination of the methamphetamine-treated animals was much better than that of controls, and swimming capacity tended to increase. While swimming, mice treated with methamphetamine mobilized more glycogen from the hepatic stores and utilized glucose more effectively. Their NEFA levels in blood were higher than those of controls. There was no difference in the muscular glycogen content.