Localization of cb1 receptors in rat`s periaqueductal gray after immobilization stress and effects of peptide tyr-w-mif- 1. immunocytochemical study

Periaqueductal gray (PAG) is a midbrain structure closely involved in the stress-induced analgesia. It suppresses nociception by the descending efferent pathways to the dorsal horn of the spinal cord. Except stimulation of opioid receptors, the PAG is specialized to produce cannabinoid-mediated stress-induced analgesia. Attractive candidates for opiate modulators are neuropeptides from Tyr-MIF-1 family. These peptides also are involved in the development of stress. Based on behavioral and anatomical data about direct interactions of cannabinoid type 1 (CB1) receptors and μ-receptors in the PAG we decided to investigate the effects of the Tyr-W-MIF-1 neuropeptide on expression of CB1 immunoreactive neurons in rat`s PAG after immobilization stress. Light microscopic study was used to determine the distribution of CB1 receptor immunoreactivity. The obtained results showed that stress itself increased the expression of CB1 immunoreactive neurons in the PAG compared with intact animals, while Tyr-W-MIF-1 decreased stress-induced CB1 expression mentioned above probably by opioid/cannabinoid interaction. Further studies are needed to understand the exact role of Tyr-W-MIF-1 on CB1 receptors in response to immobilization stress

Immunocytochemical Study Of Cb1 Receptors In Rat ‘s Periaqueductal Gray After Cold Stress And Effects Of Peptides Tyr -W-Mif -1 And Tyr -K-Mif -1

The immunohistochemical localization of cannabinoid type 1 (CB1) receptors in periaqueductal gray (PAG) of male rats after acute cold stress and effects of endogenous antiopiate peptides Tyr-W-MIF-1 and Tyr-KMIF-1 on nociception was studied. The nociception was measured by the paw pressure test. As control were used intact rats. Stress activates PAG as an important component of the descending inhibitory pain pathway and stress-induced analgesia. CB1 immunoreactivity appeared as puncta and was found in cell bodies, axons and dendrites. The morphometric analysis revealed that acute cold stress increases the density of CB1-immunoreactive neurons in PAG compared with expression in intact animals. Secund, the results showed that Tyr-K-MIF-1 and Tyr-W-MIF-1 decreased the density of CB1-immunoreactive neurons in PAG of control rats, acute cold stress and after acute cold stress and effects of endogenous antiopiate peptides Tyr-WMIF-1 and Tyr-K-MIF-on nociception

The endogenous cannabinoid and the adrenergic systems in modulation of stress-response

In our modern, fast-paced society, excessive stress (or distress) is a major risk factor for developing a plethora of diseases. There are several neuromediatory systems in the brain that regulate the response to stress, including the adrenergic and endocannabinoid systems. In our experiments, we study the effects of the endocannabinoid system on the restrain stress-induced analgesia (r-SIA). The experiments were done on male Wistar rats. The animals were confined in special restrainers for a period of one hour. The animals were treated with Clonidine (at 4 mg/kg) – a prototypical α2-agonist; Yohimbine – an α2-adrenergic receptor antagonist; Desipramine – a NE reuptake blocker; CB1r agonist anandamide (AEA); CB1r antagonist АМ251 in different combinations. r-SIA was investigated by means of the paw pressure test in order to get a better understanding of the role that the neurotransmitter anandamide plays in the process. The degree to which the levels of r-SIA fluctuated served as an indicator of the degree to which the cannabinoid system and the adrenergic system interacted with one another. Cannabinoids that are administered exogenously were found to reduce levels of r-SIA and modulate the effects of the adrenergic system. These conclusions were reached based on the findings of our research

Interaction between endocannabinoids and the adrenergic system before and after stress-exposure

Cold stress-induced analgesia (c-SIA) has been evaluated in male Wistar rats injected with cannabinoid receptors type 1 and a2-adrenergic receptor agonists and antagonists in different combinations before or after stress exposure. The aim of the study was to evaluate whether the endogenous cannabinoid and the adrenergic systems influenced c-SIA, and the patterns of their potential interaction. Exogenous administration of anandamide and Clonidine together, before or after stress exposure, increased c-SIA even with differences in the time of manifestation of the effect, its duration and the degree. The two systems differently contribute to c-SIA pathogenesis and mediation. Administered before stress exposure cannabinoids and the adrenergic system seem to oppose each other: the latter rather potentiates, while cannabinoids suppress c-SIA. Administered after stress exposure, instead, the two systems appear to exert a synergistic effect, and antagonization of each one of them abolishes the analgesic effect

Spontaneous Post-COVID-19 Pneumothorax in a Patient with No Prior Respiratory Tract Pathology: A Case Report

Spontaneous pneumothorax in the setting of coronavirus disease 19 (COVID-19) has been first described as an unlikely complication, mainly occurring in critically ill patients or as a consequence of mechanical ventilation. We report a case with COVID-19 pneumonia followed by a spontaneous pneumothorax in a young non-smoker without any predisposing pathology

Spontaneous Post-COVID-19 Pneumothorax in a Patient with No Prior Respiratory Tract Pathology: A Case Report

Spontaneous pneumothorax in the setting of coronavirus disease 19 (COVID-19) has been first described as an unlikely complication, mainly occurring in critically ill patients or as a consequence of mechanical ventilation. We report a case with COVID-19 pneumonia followed by a spontaneous pneumothorax in a young non-smoker without any predisposing pathology

Interaction between endocannabinoids and the adrenergic system before and after stress-exposure

Cold stress-induced analgesia (c-SIA) has been evaluated in male Wistar rats injected with cannabinoid receptors type 1 and a2-adrenergic receptor agonists and antagonists in different combinations before or after stress exposure. The aim of the study was to evaluate whether the endogenous cannabinoid and the adrenergic systems influenced c-SIA, and the patterns of their potential interaction. Exogenous administration of anandamide and Clonidine together, before or after stress exposure, increased c-SIA even with differences in the time of manifestation of the effect, its duration and the degree. The two systems differently contribute to c-SIA pathogenesis and mediation. Administered before stress exposure cannabinoids and the adrenergic system seem to oppose each other: the latter rather potentiates, while cannabinoids suppress c-SIA. Administered after stress exposure, instead, the two systems appear to exert a synergistic effect, and antagonization of each one of them abolishes the analgesic effect

Diabetes mellitus and hyperglycemia - pathogenesis: focus on SGLT inhibitors

Diabetes mellitus is characterized mainly by hyperglycemia, but hypoglycemic conditions are also possible under certain circumstances. The reabsorption of the solutes filtered through the renal basement membrane - sugars, anions, vitamins, short-chain fatty acids, is due to a 12-member family of transport proteins (solute carrier family 5, SLC5), incorporated into the tubular membranes. The aim of this article is to highlight the positive effects of SGLT inhibitors in clinical practice

Interactions between the cannabinoid and the serotonergic systems in modulation of pain perception

The aim of our study was to evaluate the effects of cannabinoids and serotonergic system on nociception in intact rats and after heat stress. Cannabinoid receptor type 1 (CB1) and 5-hydroxytryptamine receptor (5НТ1А) agonists and antagonists have been administered according to different experimental designs (alone and in combinations) in intact male Wistar rats, as well in animals subjected to one hour of heat stress. Pain perception has been evaluated by Paw pressure test. Our results pointed out that cannabinoids and the serotonergic system interact in nociception in intact animals as well as after heat stress. Cannabinoids seemed to have less prominent role in such interaction in intact animals than after heat stress. The interplay between the two systems probably involves different mechanisms in intact animals and after heat stress with time-dependent effects. The interaction between the cannabinoid and the serotonergic systems exerts a modulating rather than mediating effect on h-SIA

The Endogenous Cannabinoid and the Nitricoxidergic Systems in the Modulation of Stress Responses

The effects on stress-induced analgesia (SIA) from endogenous cannabinoid system (ECS) and nitric oxide (NO) interaction after 1 h of restraint stress were evaluated in male Wistar rats. The animals were subjected to 1 h of restraint and then injected with different combinations of cannabinoid receptor type 1 agonist anandamide (AEA) or antagonist AM251 along with an NO donor, NO precursor, or inhibitor of NO synthase. Nociception was evaluated using paw pressure (PP) or hot plate (HP) tests. AEA was administered immediately after the end of restraint-SIA (r-SIA). Administration of NO precursor reversed the pronociceptive effect of the CB1 agonist on r-SIA. Both the CB1 antagonist and the NOS inhibitor neutralized the pro-analgesic effect of L-arginine (L-arg). Administration of an NO donor, instead, increased r-SIA. Our experiments confirmed that the endogenous cannabinoid and the NO-ergic systems interact in the modulation of r-SIA. This interaction probably implies NO as a second messenger of the ECS