Dopamine hydrochloride

Dopamine HCl is a catecholamine neurotransmitter present in a wide variety of animals,And a dopamine D1-5 receptors agonist.

Cardiovascular effects of dopamine hydrochloride and phenylephrine hydrochloride in healthy isoflurane-anesthetized New Zealand White rabbits (Oryctolagus cuniculus).[Pubmed:25629908]

Am J Vet Res. 2015 Feb;76(2):116-21.

OBJECTIVE: To determine the cardiopulmonary effects of progressively increasing infusion rates of Dopamine hydrochloride and phenylephrine hydrochloride in healthy adult New Zealand White rabbits anesthetized with isoflurane. ANIMALS: 6 New Zealand White rabbits. (Oryctolagus cuniculus). PROCEDURES: Each rabbit was anesthetized on 2 occasions (>/= 2 weeks apart) with isoflurane in oxygen at 1.5 times the published isoflurane minimum alveolar concentration of 2.07%. Carotid artery and pulmonary artery catheters were placed. During each anesthetic episode, each rabbit received 5 progressively increasing doses of either dopamine (5, 10, 15, 20, or 30 mug/kg/min) or phenylephrine (0.125, 0.25, 0.5, 1.0, and 2.0 mug/kg/min). Blood gas and cardiopulmonary measurements were obtained after a 20-minute equilibration period prior to administration of the first drug dose (baseline) and after each subsequent dose administration. RESULTS: Dopamine increased stroke index at the highest infusion rate of 30 mug/kg/min; however, cardiac output and mean arterial blood pressure remained unchanged from baseline values. Administration of phenylephrine at a rate of 2 mug/kg/min increased mean arterial blood pressure to 62 mm Hg from the baseline value of 45 mm Hg. This was a result of an increase in systemic vascular resistance with a concomitant decrease in heart rate and no change in cardiac output. Blood lactate concentration increased with time when rabbits received either treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Within the dose range of 5 to 30 mug/kg/min, dopamine was not an effective treatment for isoflurane-induced hypotension in rabbits and phenylephrine was only minimally effective at a dose of 2 mug/kg/min.

Conformation and interactions of dopamine hydrochloride in solution.[Pubmed:25573567]

J Chem Phys. 2015 Jan 7;142(1):014502.

The aqueous solution of Dopamine hydrochloride has been investigated using neutron and X-ray total scattering data together with Monte-Carlo based modelling using Empirical Potential Structure Refinement. The conformation of the protonated dopamine molecule is presented and the results compared to the conformations found in crystal structures, dopamine-complexed protein crystal structures and predicted from theoretical calculations and pharmacophoric models. It is found that protonated dopamine adopts a range of conformations in solution, highlighting the low rotational energy barrier between different conformations, with the preferred conformation being trans-perpendicular. The interactions between each of the species present (protonated dopamine molecules, water molecules, and chloride anions) have been determined and are discussed with reference to interactions observed in similar systems both in the liquid and crystalline state, and predicted from theoretical calculations. The expected strong hydrogen bonds between the strong hydrogen bond donors and acceptors are observed, together with evidence of weaker CH hydrogen bonds and pi interactions also playing a significant role in determining the arrangement of adjacent molecules.

Role of dopamine in the motivational and cognitive control of behavior.[Pubmed:18660464]

Neuroscientist. 2008 Aug;14(4):381-95.

Brain dopamine has often been implicated in impulsive and/or inflexible behaviors, which may reflect failures of motivational and/or cognitive control. However, the precise role of dopamine in such failures of behavioral control is not well understood, not least because they implicate paradoxical changes in distinct dopamine systems that innervate dissociable neural circuits. In addition, there are large individual differences in the response to dopaminergic drugs with some individuals benefiting from and others being impaired by the same drug. This complicates progress in the understanding of dopamine's role in behavioral control processes, but also provides a major problem for neuropsychiatry, where some individuals are disproportionately vulnerable to the adverse effects of dopamine-enhancing drugs on motivation and cognition. Recent progress is reviewed from cognitive and behavioral neuroscience research on motivation and cognitive control, which begins to elucidate the factors that mediate the complex roles of mesolimbic, mesocortical, and nigrostriatal dopamine in behavioral control.

Novel insights in dopamine receptor physiology.[Pubmed:17413183]

Eur J Endocrinol. 2007 Apr;156 Suppl 1:S13-21.

The dopaminergic system has a pivotal role in the central nervous system but also plays important roles in the periphery, mainly in the endocrine system. Dopamine exerts its functions via five different receptors, named D(1)-D(5), belonging to the category of G protein coupled membrane receptors. Dopamine receptors are heterogeneously expressed in different cells, tissues and organs, where they stimulate or inhibit different functions, including neurotransmission and hormone synthesis and secretion. In particular, the dopamineric system has a pivotal role in the physiological regulation of the hypothalamus-pituitary-adrenal axis. Recent data have demonstrated the expression and function of dopamine receptors not only in endocrine organs but also in endocrine tumors, mainly those belonging to the hypothalamus-pituitary-adrenal axis, and also in the so-called 'neuroendocrine' tumors. These data confirm the important role of the dopaminergic system in this endocrine axis, as well as in the neuroendocrine system. This review summarizes the main structural and functional characteristics of dopamine receptors, emphasizing the most recent novelties, and focused on the physiological and pathological regulation of the hypothalamus-pituitary-adrenal axis by the dopaminergic system. In addition, the recent findings on the relationship between dopamine receptors and neuroendocrine tumors are summarized.