To assess whether diabetes alters the regulatory effects of mu-opioid receptor (MOR) agonists on the cholinergic bronchoconstriction, we investigated the inhibitory effects of endomorphins (EMs) on the electrical field stimulation (EFS)-induced cholinergic bronchoconstriction in type 1 diabetic rats. At 4 weeks after the onset of diabetes, both the EFS- and exogenous acetylcholine (ACh)-induced bronchoconstriction in diabetes in vitro were greater than those in non-diabetes rats. Furthermore, endomorphin 1 (EM1) and endomorphin 2 (EM2) inhibited the response to EFS in diabetic rat isolated bronchus in a concentration- and frequency-dependent manner, which is in agreement with that in non-diabetes. However, the inhibitory effects of EMs on the EFS-induced bronchoconstriction in diabetes were significantly weaker than those in non-diabetes. Both EM1 and EM2 (1 microM) had no effect on the contractile response to exogenous ACh, indicating a prejunctional effect. Furthermore, the inhibitory effect on the EFS-induced bronchoconstriction was blocked by naloxone (10 microM). Eight weeks after the induction of diabetes, both the EFS- and exogenous ACh-induced bronchoconstrictions in diabetes were further enhanced compared to those in short-time (4 weeks) diabetic rats. Moreover, the inhibitory effects of EMs on the EFS-induced bronchoconstriction were further attenuated. These results suggest that dysfunction of presynaptic inhibitory modulation through opioid receptor by EMs may take place in the bronchus of diabetic rats.
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http://dx.doi.org/10.1016/j.peptides.2006.06.002 | DOI Listing |
Front Biosci (Landmark Ed)
January 2025
Department of Biomedical Sciences, Grand Valley State University, Allendale, MI 49401, USA.
Background: Diabetes mellitus is associated with morphological and functional impairment of the heart primarily due to lipid toxicity caused by increased fatty acid metabolism. Extracellular signal-regulated protein kinases 1 and 2 (ERK1/2) have been implicated in the metabolism of fatty acids in the liver and skeletal muscles. However, their role in the heart in diabetes remains unclear.
View Article and Find Full Text PDFNutrients
January 2025
Department of Pharmacology, Faculty of Pharmaceutical Sciences in Sosnowiec, Medical University of Silesia, 40-055 Katowice, Poland.
Background: It seems that some substances of plant origin may exert health-promoting activities in diabetes and its complications, including those concerning bones. Chrysin (5,7-dihydroxyflavone), present in honey, some plants, and food of plant origin, has been reported to exert, among others, antioxidative, anti-inflammatory and antidiabetic effects. The aim of this study was to investigate the effects of chrysin on the skeletal system of rats with experimental type 1 diabetes (T1D).
View Article and Find Full Text PDFNutrients
January 2025
Instituto de Bioeletricidade Celular (IBIOCEL): Ciência & Saúde, Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Rua João Pio Duarte Silva, 241, Sala G 301, Florianópolis 88038-000, SC, Brazil.
Diabetes mellitus is a metabolic syndrome that has grown globally to become a significant public health challenge. Hypothesizing that the plasma membrane protein, transient receptor potential ankyrin-1, is a pivotal target in insulin resistance, we investigated the mechanism of action of cinnamaldehyde (CIN), an electrophilic TRPA1 agonist, in skeletal muscle, a primary insulin target. Specifically, we evaluated the effect of CIN on insulin resistance, hepatic glycogen accumulation and muscle and adipose tissue glucose uptake.
View Article and Find Full Text PDFNutrients
January 2025
Department of Human Physiology, School of Laboratory Medicine and Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban 4000, South Africa.
Background: Prediabetes is a condition that often precedes the onset of type 2 diabetes mellitus (T2DM). Literature evidence indicates that prediabetes is reversible, making it an important therapeutic target for preventing the progression to T2DM. Several studies have investigated intermittent fasting as a possible method to manage or treat prediabetes.
View Article and Find Full Text PDFNutrients
January 2025
Department of Pharmacy and Master Program, Collage of Pharmacy and Health Care, Tajen University, Yanpu Township 90741, Taiwan.
: This study investigated the wound-healing potential of hispolon, a polyphenolic pigment derived from medicinal mushrooms, under diabetic conditions using both in vitro and in vivo models. : In the in vitro assays, L929 fibroblast cells exposed to high glucose (33 mmol/L) were treated with hispolon at concentrations of 2.5, 5, 7.
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