Apomorphine in the evaluation of dopaminergic function in man

Area of Science:

• Neuroscience
• Pharmacology
• Endocrinology

Background:

• Apomorphine (Apo) is a dopamine (DA) receptor agonist with diverse physiological effects, including growth hormone (GH) secretion, prolactin reduction, yawning, and penile erections.
• Apo-mediated responses are utilized to assess DA function in psychiatric and neurological disorders, though interpretation is often complicated by uncontrolled variables.
• The GH response to Apo serves as a valuable tool for evaluating the impact of various drugs, including peptides, on central DA function in humans.

Purpose of the Study:

• To explore the multifaceted applications of Apomorphine in evaluating dopamine function across various clinical and research settings.
• To highlight the potential and limitations of using Apo-mediated responses, such as GH secretion and yawning, as biomarkers for neurological and psychiatric conditions.
• To discuss the challenges and future directions in utilizing Apomorphine for therapeutic interventions and diagnostic purposes.

Main Methods:

• Review of existing literature on Apomorphine's physiological and behavioral effects.
• Analysis of Apomorphine's utility in assessing dopamine function through growth hormone (GH) response and yawning.
• Consideration of advanced imaging techniques like 18F-fluorodeoxyglucose positron emission tomography in conjunction with Apo.

Main Results:

• Apomorphine stimulates GH secretion and reduces prolactin, offering insights into central dopamine activity.
• Apo shows promise in improving parkinsonian symptoms and certain epilepsies, but its efficacy in other movement disorders needs further research.
• Apomorphine may aid in evaluating dopamine function in impotence and predicting responses to dopaminergic agents, particularly in diabetic cases.

Conclusions:

• Apomorphine is a valuable pharmacological tool for probing dopamine system function in humans, with applications in both research and clinical diagnostics.
• While Apo has demonstrated therapeutic potential in specific conditions like Parkinson's disease, its broader clinical utility is limited by side effects and tolerance.
• Further research, including well-controlled studies and advanced imaging, is needed to fully elucidate Apomorphine's role in managing neurological and psychiatric disorders.