D-Amphetamine sulfate

Differential sexual activity of isolated and group-housed male mice: influence of acute d-amphetamine sulfate administration.[Pubmed:8743635]

Pharmacol Biochem Behav. 1996 Jul;54(3):601-4.

It is established that group housing can impair sexual activity of male mice, and that central catecholamines are involved in male sexual response, but it is not known whether catecholamine mechanisms are involved in sexual impairment in grouped males. Injections of 0, 0.22, 0.67, 2.0, or 6.0 mg/kg of D-Amphetamine sulfate were administered 1 h before testing to individually and group-housed male C57BL/6J mice. Isolated mice showed more mounts, intromissions, and ejaculations and shorter response latencies than did group-housed mice. The latencies to first mount, intromission, and ejaculation were nonmonotonically related to dosage, being shortest at the lowest dosage in isolated mice, but significantly elevated by the higher dosages in both isolated and grouped males. The number of ejaculations was significantly elevated by moderate dosages in both isolated and grouped mice, peaking at the 2.0 mg/kg dosage in isolated mice and at 0.67 mg/kg in grouped mice. Nevertheless, amphetamine treatment generally failed to eliminate differences between males from isolated and grouped backgrounds.

Lattice dynamics through the structural phase transition in D-amphetamine sulfate.[Pubmed:22978803]

J Phys Chem A. 2012 Oct 11;116(40):9854-62.

The polarized infrared and Raman spectra of the single-crystalline D-Amphetamine sulfate have been measured as a function of temperature in the vicinity of the structural phase transition. Infrared and Raman-active modes are identified and assigned. Significant signatures of the structural phase transition are observed in the temperature dependence of infrared modes both of the D-amphetamine unit and the sulfate anion. The changes reflect differences in the unit cell between low- and high-temperature phases of the D-Amphetamine sulfate. Temperature dependence of the vibrational mode parameters displays pronounced hysteresis between 333 and 338 K that is extended over a smaller temperature range than 325-345 K found in the earlier DSC study.

Balance between dopamine and serotonin release modulates behavioral effects of amphetamine-type drugs.[Pubmed:17105921]

Ann N Y Acad Sci. 2006 Aug;1074:245-60.

The abuse of illicit stimulants is a worldwide crisis, yet few medicines are available for treating stimulant addiction. We have advocated the idea of "agonist therapy" for cocaine dependence. This strategy involves administration of stimulant-like medications (e.g., monoamine releasers) to alleviate cocaine withdrawal symptoms and prevent relapse. A chief limitation of this strategy is that many candidate medicines possess high abuse liability due to activation of mesolimbic dopamine (DA) neurons in reward pathways. Evidence suggests that serotonin (5-HT) neurons can provide an inhibitory influence over mesolimbic DA neurons. Thus, it might be predicted that the balance between DA and 5-HT transmission is a critical variable when developing medications with reduced stimulant side effects. In this article, we review recent studies from our laboratory that examined neurochemical and behavioral effects of a series of monoamine releasers which displayed different potencies at DA and 5-HT transporters. The data show that increasing 5-HT release can attenuate stimulant effects mediated by DA release, such as motor stimulation and drug self-administration. Our findings support the work of others and indicate that elevated synaptic 5-HT can dampen certain behavioral effects of DA-releasing agents. Moreover, the relationship between DA and 5-HT releasing potency is an important determinant in developing new agonist medications with reduced stimulant properties.

Effects of withdrawal from an escalating dose schedule of d-amphetamine on sexual behavior in the male rat.[Pubmed:10548277]

Pharmacol Biochem Behav. 1999 Nov;64(3):597-604.

The present study sought to determine the effect of withdrawal from an escalating dose schedule of d-amphetamine on sexual behavior in male rats. Tests were conducted every 5 days until stable levels of sexual behavior were obtained. With repeated testing, male rats displayed an increase in their exploration of the testing chambers prior to the introduction of an estrous female. Half of the male rats were then subjected to a 4-day escalating dose schedule of d-amphetamine administration (1-12 mg/kg), while half received vehicle. Twelve hours after the final drug injection, subjects were tested for sexual behavior. Withdrawal from the drug was associated with decrements in several motivational components of sexual behavior, including decreased anticipatory locomotor and increased postejaculatory intervals, while consummatory measures remained largely unaffected. This pattern of sexual deficits resembles those seen in human depressive disorders, and therefore, provides additional support for the use of psychostimulant withdrawal as a rodent model of depression.

The metabotropic glutamate 2/3 receptor agonists LY354740 and LY379268 selectively attenuate phencyclidine versus d-amphetamine motor behaviors in rats.[Pubmed:10490900]

J Pharmacol Exp Ther. 1999 Oct;291(1):161-70.

Previous animal studies have indicated that drugs targeted at metabotropic glutamate (mGlu) receptors may be useful for treatment of psychosis. In this article, the effects of the novel, potent, and selective mGlu2/3 receptor agonists LY354740 and LY379268, and the clinically effective agents clozapine and haloperidol, were investigated using phencyclidine (PCP; 5 mg/kg)- versus d-amphetamine (AMP; 3 mg/kg)-evoked motor activities. LY354740 (1-10 mg/kg s.c.), LY379268 (0.3-3 mg/kg s.c.), clozapine (1-10 mg/kg s.c.), and haloperidol (0.03-1 mg/kg s.c.) reversed the increases in ambulations, fine motor (nonambulatory) movements, and decreased time at rest evoked by PCP. Furthermore, the inhibitions of the PCP response by the mGlu2/3 agonist LY379268, but not by clozapine, were completely reversed by the selective mGlu2/3 receptor antagonist LY341495. Doses of LY354740 and LY379268 that blocked the effects on PCP had no effects on rotorod performance, and (with the exception of rearing behavior) had minimal effects on AMP-evoked motor activities. Clozapine blocked AMP-induced rearing but enhanced AMP-induced ambulations and fine movements at the lower doses (1 and 3 mg/kg). Unlike the mGlu2/3 agonists, the highest dose of clozapine tested (10 mg/kg) impaired animals on the rotorod. Haloperidol potently blocked all PCP and AMP effects, but only at doses associated with motor impairment. These data demonstrate that mGlu2/3 receptor agonists act via a unique mechanism to selectively block PCP-induced behaviors. Moreover, the marked mGlu2/3 receptor-mediated inhibitions of PCP-evoked behaviors by LY354740 and LY379268, with minimal effects on AMP, may indicate potential antipsychotic effects in humans in the absence of dopamine mediated extrapyramidal side effects.