Development and challenges in the discovery of 5-HT1A and 5-HT7 receptor ligands.

Serotonin (5-hydroxytryptamine) is a small molecule that acts both in the central and peripheral nervous system as a neurotransmitter and a hormone, respectively. Serotonin is synthesized via a multi-stage pathway beginning with l-tryptophan, which is converted by an enzyme called tryptophan hydroxylase into L-5-Hydroxytryptophan. It is well-known for its significance in the control of mood, anxiety, depression, and insomnia as well as in normal human functions such as sleep, sexual activity, and appetite. Thus, for medical chemists and pharmaceutical firms, serotonin is one of the most desirable targets. Among the seven different classes of serotonin receptors, the 5-HT1A was one of the first discovered serotonin receptors, and the 5-HT7 was the last addition to the serotonin receptor family. Both the classes were thoroughly examined. 5-HT1A neurotransmission-related dysfunctions are linked to many psychological conditions such as anxiety, depression, and movement disorders. 5-HT7 is a member of the cell surface receptor GPCR superfamily and is regulated by the serotonin neurotransmitter. It has been the focus of intensive research efforts since its discovery, which was prompted by its presence in functionally important regions of the brain. The thalamus and hypothalamus have the highest 5-HT7 receptor densities. They are also found in the hippocampus and cortex at higher densities. Thermoregulation, circadian rhythm, learning and memory, and sleep are all associated with the 5-HT7 receptor. It is also suspected that this receptor may be involved in the control of mood, indicating that it may be a beneficial target for depression treatment. Several differently structured molecules such as aminotetralins, ergolines, arylpiperazines, indolylalkylamines, aporphines, and aryloxyalkyl-amines are known to bind to 5-HT1A and 5-HT7 receptor sites. In brain serotonin receptors 5-HT1A and 5-HT7 are strongly co-expressed in regions involved in depression. However, their functional interaction has not been identified. An overview of the 5-HT1A and 5-HT7 receptor ligands belonging to different chemical groups is mentioned in this review.

Effects of the 5-HT2A receptor antagonist volinanserin on head-twitch response and intracranial self-stimulation depression induced by different structural classes of psychedelics in rodents.

BACKGROUND: Clinical studies suggest that psychedelics exert robust therapeutic benefits in a number of psychiatric conditions including substance use disorder. Preclinical studies focused on safety and efficacy of these compounds are necessary to determine the full range of psychedelics' effects. OBJECTIVES: The present study explores the behavioral pharmacology of structurally distinct psychedelics in paradigms associated with serotonin 2A receptor (5-HT2AR) activation and behavioral disruption in two rodent models. Utilizing the selective 5-HT2AR antagonist volinanserin, we aimed to provide further pharmacological assessment of psychedelic effects in rodents. METHODS: We compared volinanserin (0.0001-0.1 mg/kg) antagonism of the phenethylamine 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI, 1.0 mg/kg) and the ergoline lysergic acid diethylamide (LSD, 0.32 mg/kg) in preclinical assays predictive of hallucinations (head-twitch response or HTR in mice) and behavioral disruption (intracranial self-stimulation or ICSS in rats). Volinanserin antagonism of the phenethylamine mescaline, the tryptamine psilocybin, and the k-opioid receptor agonist salvinorin A was also evaluated in the rat ICSS assay. RESULTS: Volinanserin had similar potency, effectiveness, and time-course to attenuate DOI-induced HTR in mice and ICSS depression in rats. Volinanserin completely blocked LSD-induced HTR in mice, but not LSD-induced ICSS depression in rats. Volinanserin also reversed ICSS depression by mescaline, but it was only partially effective to reduce the effects of psilocybin, and it exacerbated ICSS depression by salvinorin A. CONCLUSION: Although hallucination-related HTR behavior induced by phenethylamine, ergoline, and tryptamine psychedelics appears to be 5-HT2AR-mediated, the receptor(s) responsible for behavioral disruptive effects may differ among these three structural classes.

Chemistry and Structure-Activity Relationships of Psychedelics.

This chapter will summarize structure-activity relationships (SAR) that are known for the classic serotonergic hallucinogens (aka psychedelics), focusing on the three chemical types: tryptamines, ergolines, and phenethylamines. In the brain, the serotonin 5-HT2A receptor plays a key role in regulation of cortical function and cognition, and also appears to be the principal target for hallucinogenic/psychedelic drugs such as LSD. It is one of the most extensively studied of the 14 known types of serotonin receptors. Important structural features will be identified for activity and, where possible, those that the psychedelics have in common will be discussed. Because activation of the 5-HT2A receptor is the principal mechanism of action for psychedelics, compounds with 5-HT2A agonist activity generally are quickly discarded by the pharmaceutical industry. Thus, most of the research on psychedelics can be related to activation of 5-HT2A receptors. Therefore, much of the discussion will include not only clinical or anecdotal studies, but also will consider data from animal models as well as a certain amount of molecular pharmacology where it is known.

[Current diagnosis and treatment of hyperprolactinemia]. / Diagnóstico y tratamiento actual de la hiperprolactinemia.

Hyperprolactinemia is a frequent neuroendocrinological condition that should be approached in an orderly and integral fashion, starting with a complete clinical history. Once physiological causes such as pregnancy, systemic disorders such as primary hypothyroidism and the use of drugs with dopamine antagonistic actions such as metochlopramide have been ruled out, the most common cause of hyperprolactinemia is a PRL-secreting pituitary adenoma or prolactinoma. Prolactinomas are usually classified as microprolactinomas (less than 1 cm) or macroprolactinomas (larger than 1 cm), which can either be confined or invasive. The hormonal consequence of hypeprolactinemia is hypogonadism; in women, this is manifested as amenorrhea/oligomenorreha, anovulation and galactorrhea, whereas in men the main complaints are a diminished libido and erectile dysfunction. Macroprolactinomas can also present with symptoms and signs resulting form mass effect of the tumor, such as headaches and visual field defects. Other structural causes of hyperprolactinemia include non-functioning pituitary adenomas and infiltrative disorders, which can interrupt the inhibitory, descending dopaminergic tone. The primary treatment of prolactinomas is pharmacological with dopamine agonists such as cabergoline.

La hiperprolactinemia es uno de los trastornos neuroendocrinológicos más frecuentes y su abordaje debe hacerse de manera ordenada e integral, partiendo de una historia clínica completa. Una vez excluidas las causas fisiológicas, como el embarazo, enfermedades sistémicas (como el hipotiroidismo primario) y el uso de fármacos con acción antidopaminérgica (como la metoclopramida), la causa más común de la hiperprolactinemia es la presencia de un adenoma hipofisario productor de prolactina (PRL) o prolactinoma. Los prolactinomas se clasifican por su tamaño en microprolactinomas (menores de 1 cm) y macroprolactinomas (mayores de 1 cm), los cuales a su vez pueden ser intraselares o invasivos. La consecuencia hormonal de la hiperprolactinemia es el hipogonadismo; en la mujer, esto se manifiesta como amenorrea/oligomenorrea, anovulación y galactorrea, mientras que en el hombre la manifestación consiste en la disminución de la libido y disfunción eréctil. En el caso de los macroprolactinomas, no es infrecuente encontrar síntomas y signos de efecto de masa como cefalea y alteraciones en los campos visuales. Otras causas estructurales de hiperprolactinemia son los adenomas no funcionantes y las enfermedades infiltrativas de la hipófisis, las cuales interrumpen el tono dopaminérgico descendente. El tratamiento primario de los prolactinomas es farmacológico, a base de agonistas dopaminérgicos, como la cabergolina.

Galactorreia: como abordar essa complicação incomum após mamoplastia de aumento / Galactorrhea: how to address this unusual complication after augmentation mammoplasty

INTRODUÇÃO: Galactorreia e formação de galactocele após mamoplastia de aumento é uma complicação descrita na literatura, porém a causa permanece desconhecida. MÉTODOS: Apresentamos um caso de uma paciente de 28 anos que foi submetida à cirurgia de mamoplastia de aumento via sulco inframamário, com implante colocado no plano subfascial, que evoluiu, no 7º dia pós-operatório, com galactorreia exteriorizada pela incisão, e propomos um algoritmo para diagnóstico e tratamento de galactorreia após mamoplastias. RESULTADOS: A complicação foi tratada com o uso de agente supressor da lactação, a cabergolina, apresentando boa evolução. CONCLUSÃO: Galactorreia é uma complicação incomum após mamoplastias de aumento, que deve ser sempre lembrada em casos de drenagem de secreção pela incisão por tratar-se de um diagnóstico diferencial com infecção.

INTRODUCTION: Galactorrhea and galactocele formation after breast augmentation are complications reported in the literature, but the cause remains unknown. METHODS: We present a case of a 28-year-old patient who underwent breast augmentation surgery via the inframammary fold with an implant placed in the subfascial plane, which developed galactorrhea from the incision on the seventh postoperative day, and we propose an algorithm for the diagnosis and treatment of galactorrhea after mammoplasties. RESULTS: The complication was treated with the use of a lactation suppressor, cabergoline, presenting good outcomes. CONCLUSION: Galactorrhea is an uncommon complication after augmentation mammoplasties, which should always be considered in cases of secretions from an incision because it is a differential diagnosis for infections.

Drug laws and the 'derivative' problem.

The concept of a 'derivative' is used widely in chemistry, where its precise meaning depends on the circumstances. However, numerous examples of derivative also occur in domestic drugs legislation, some of which stem from the 1961 United Nations Single Convention on Narcotic Drugs. There is a commonly held view that only 'first-order' derivatives should be considered: substances that can be created from a parent structure in a single chemical reaction. In other words, 'derivatives of derivatives' are excluded. However, some substances related to ecgonine (e.g. 2-carbomethoxytropinone) are clearly convertible to cocaine, even though this may require more than one reaction step. It follows that 2-carbomethoxytropinone is a controlled drug, a situation that most chemists would regard as perverse. A more extreme example of the complexity of 'derivative' is shown by the conversion of thebaine to buprenorphine. Even though this requires six or more stages, the US Drug Enforcement Administration successfully argued in a 1986 case that for the purposes of the Controlled Substances Act, the number of steps required was irrelevant; buprenorphine was a derivative of thebaine. Because the term derivative is rarely defined in statutes, the legal status of some substances, such as 2-bromo-LSD, is uncertain. Although a number of definitions of derivative can be found in the chemical literature, no single definition is adequate to describe all situations where it occurs in legislation. Unless qualified, it is suggested that the term derivative should be avoided in any future legislation.