The Role of Adrenoceptors in the Retina

Abstract

The retina is a part of the central nervous system, a thin multilayer with neuronal lamination, responsible for detecting, preprocessing, and sending visual information to the brain. Many retinal diseases are characterized by hemodynamic perturbations and neurodegeneration leading to vision loss and reduced quality of life. Since catecholamines and respective bindings sites have been characterized in the retina, we systematically reviewed the literature with regard to retinal expression, distribution and function of alpha1 (α1)-, alpha2 (α2)-, and beta (β)-adrenoceptors (ARs). Moreover, we discuss the role of the individual adrenoceptors as targets for the treatment of retinal diseases.

Regulation of Adrenergic, Serotonin, and Dopamine Receptors to Inhibit Diabetic Retinopathy: Monotherapies versus Combination Therapies

“…Receptors affected by these drugs are found in the retina (Chen et al, 2013;Ruan et al, 2020), but it cannot be assumed that the beneficial effects of the drugs were mediated via drug effects in those retinal cells. The drugs used by us act also on other cell-types not residing in the eye (including leukocytes), resulting in anti-inflammatory and anti-oxidant effects (Chen et al, 2016b;Dunzendorfer and Wiedermann, 2000;García-Prieto et al, 2017;Grisanti et al, 2011;Heijnen et al, 1996;King, 2017;Kintscher et al, 2001;Takahashi et al, 2005).…”

Scientific rationale for the use of α2A-adrenoceptor agonists in treating neuroinflammatory cognitive disorders

“…In rodent models of TBI, dexmedetomidine was shown to reduce monocyte-derived macrophage infiltration into brain [171], and to reduce autophagy and neuroinflammation [172]. α2A-AR are also expressed by retinal ganglion cells, and basic research indicates that α2-AR stimulation in retina is neuroprotective [173]. Thus, α2A-AR agonists may protect against cell death under severe conditions, but may also protect neuronal function needed for higher cognition under more mild conditions by reducing the production of kynurenine and/or GCPII from macrophages and microglia by producing an anti-inflammatory state.…”

The Role of Beta-Adrenergic Receptors in Depression and Resilience

“…Adrenoceptors, a superfamily of guanosine triphosphate-binding protein (G protein)-coupled receptors (GPCRs), are receptors activated by epinephrine and norepinephrine [ 28 ]. According to its pharmacological properties, amino acid sequence, and signaling mechanisms, the adrenoceptor superfamily is classified into three subfamilies: the alpha1-, alpha2-, and beta-adrenoceptor subfamilies.…”

“…According to its pharmacological properties, amino acid sequence, and signaling mechanisms, the adrenoceptor superfamily is classified into three subfamilies: the alpha1-, alpha2-, and beta-adrenoceptor subfamilies. The beta-adrenoceptor subfamily comprises the beta-1, beta-2, and beta-3 subtypes [ 28 ]. Beta-adrenoceptors are widely distributed in the nervous and non-nervous systems and are involved in the adaptation and maladaptation to social and environmental stimuli, as well as muscular system-related activities such as vasorelaxation and bronchodilation [ 25 , 28 , 29 , 30 ].…”

“…The beta-adrenoceptor subfamily comprises the beta-1, beta-2, and beta-3 subtypes [ 28 ]. Beta-adrenoceptors are widely distributed in the nervous and non-nervous systems and are involved in the adaptation and maladaptation to social and environmental stimuli, as well as muscular system-related activities such as vasorelaxation and bronchodilation [ 25 , 28 , 29 , 30 ].…”