Dopamine receptor 3: A mystery at the heart of cardiac fibrosis

Pulmonary Fibrosis in a Patient With a Prolactinoma on Dopamine Agonists: Coincidence or Consequence

Prolactinomas are the most common functional pituitary tumor and are typically managed with dopamine agonists such as bromocriptine or cabergoline. Although these agents are generally well tolerated and effective in reducing prolactin levels and often tumor size, they have been implicated in rare but serious fibrotic complications, including interstitial lung disease (ILD). We describe a 65-year-old man with a longstanding prolactinoma who received cumulative high-dose bromocriptine and cabergoline therapy over several decades. Despite initial tumor shrinkage and partial biochemical control of hyperprolactinemia with dopamine agonists, stereotactic radiosurgery, and transsphenoidal surgery, the patient developed progressive exertional dyspnea and cough, accompanied by imaging and histopathological findings consistent with "usual interstitial pneumonia" (UIP). Autoimmune and environmental causes were largely excluded, suggesting a drug-induced etiology. Following discontinuation of cabergoline, the patient has been on continued surveillance of his prolactin levels and tumor status, with symptomatic treatment of his UIP. This case underscores the potential for dopamine agonist-associated ILD, even in patients with prolactinomas who generally receive lower weekly doses than those used in Parkinson's and related diseases. Early recognition of respiratory symptoms, pulmonary function, and radiological investigations are indicated in selected symptomatic cases.

Sedative and hypnotic effects of the saponins from a traditional edible plant Liriope spicata Lour. in PCPA-induced insomnia mice

ETHNOPHARMACOLOGICAL RELEVANCE

Liriope spicata Lour., a species listed in the catalogue of 'Medicinal and Edible Homologous Species', is traditionally used for the treatment of fatigue, restlessness, insomnia and constipation.

AIM OF THE STUDY

This study is aimed to evaluate the sedative and hypnotic effect of the saponins from a natural plant L. spicata Lour. in vivo.

MATERIALS AND METHODS

The total saponin (LSTS) and purified saponin (LSPS) were extracted from L. spicata, followed by a thorough analysis of their major components using the HPLC-MS. Subsequently, the therapeutic efficacy of LSTS and LSPS was evaluated by the improvement of anxiety and depression behaviors of the PCPA-induced mice.

RESULTS

LSTS and LSPS exhibited similar saponin compositions but differ in their composition ratios, with liriopesides-type saponins accounting for a larger proportion in LSTS. Studies demonstrated that both LSTS and LSPS can extend sleep duration and immobility time, while reducing sleep latency in PCPA-induced mice. However, there was no significant difference in weight change among the various mice groups. Elisa results indicated that the LSTS and LSPS could decrease levels of NE, DA, IL-6, and elevate the levels of 5-HT, NO, PGD2 and TNF-α in mice plasma. LSTS enhanced the expression of neurotransmitter receptors, while LSPS exhibited a more pronounced effect in regulating the expression of inflammatory factors. In conclusion, the saponins derived from L. spicata might hold promise as ingredients for developing health foods with sedative and hypnotic effects, potentially related to the modulation of serotonergic and GABAAergic neuron expression, as well as immunomodulatory process.

Microdosing psychedelics and the risk of cardiac fibrosis and valvulopathy: Comparison to known cardiotoxins

Though microdosing psychedelics has become increasingly popular, its long-term effects on cardiac health remain unknown. Microdosing most commonly involves ingesting sub-threshold doses of lysergic acid diethylamide (LSD), psilocybin, or other psychedelic drugs 2-4 times a week for at least several weeks, but potentially months or years. Concerningly, both LSD and psilocybin share structural similarities with medications which raise the risk of cardiac fibrosis and valvulopathy when taken regularly, including methysergide, pergolide, and fenfluramine. 3,4-Methylenedioxymethamphetamine, which is also reportedly used for microdosing, is likewise associated with heart valve damage when taken chronically. In this review, we evaluate the evidence that microdosing LSD, psilocybin, and other psychedelics for several months or more could raise the risk of cardiac fibrosis. We discuss the relationship between drug-induced cardiac fibrosis and the 5-HT2B receptor, and we make recommendations for evaluating the safety of microdosing psychedelics in future studies.

Assessment of the relationship between the dopaminergic pathway and severe acute respiratory syndrome coronavirus 2 infection, with related neuropathological features, and potential therapeutic approaches in COVID-19 infection

Dopamine is a known catecholamine neurotransmitter involved in several physiological processes, including motor control, motivation, reward, cognition, and immune function. Dopamine receptors are widely distributed throughout the nervous system and in immune cells. Several viruses, including human immunodeficiency virus and Japanese encephalitis virus, can use dopaminergic receptors to replicate in the nervous system and are involved in viral neuropathogenesis. In addition, studies suggest that dopaminergic receptors may play a role in the progression and pathogenesis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. When SARS-CoV-2 binds to angiotensin-converting enzyme 2 receptors on the surface of neuronal cells, the spike protein of the virus can bind to dopaminergic receptors on neighbouring cells to accelerate its life cycle and exacerbate neurological symptoms. In addition, recent research has shown that dopamine is an important regulator of the immune-neuroendocrine system. Most immune cells express dopamine receptors and other dopamine-related proteins, indicating the importance of dopaminergic immune regulation. The increase in dopamine concentration during SARS-CoV2 infection may reduce immunity (innate and adaptive) that promotes viral spread, which could lead to neuronal damage. In addition, dopaminergic signalling in the nervous system may be affected by SARS-CoV-2 infection. COVID -19 can cause various neurological symptoms as it interacts with the immune system. One possible treatment strategy for COVID -19 patients could be the use of dopamine antagonists. To fully understand how to protect the neurological system and immune cells from the virus, we need to study the pathophysiology of the dopamine system in SARS-CoV-2 infection.