Alpha1-adrenergic stimulation, coupled to Gq, has been shown to promote heart failure. However, the role of alpha1-adrenergic signaling in the regulation of myocardial contractility in failing myocardium is still poorly understood. To investigate this, we observed 1) the effect of phenylephrine on myofibrillar Ca2+ sensitivity in alpha-toxin-skinned cardiomyocytes, and 2) protein expression of Gq, RhoA, and myosin light chain phosphorylation using tachypacing-induced canine failing hearts. Phenylephrine significantly increased myofibrillar Ca2+ sensitivity in failing but not in normal cardiomyocytes. Whereas Y-27632 (Rho kinase inhibitor) blocked the phenylephrine-induced Ca2+ sensitization in the failing myocytes, calphostin C (protein kinase C inhibitor) had no effect on Ca2+ sensitization. The protein expression of Galpha(q) and RhoA and the phosphorylation level of regulatory myosin light chain significantly increased in the failing myocardium. Our results suggest that alpha1-adrenoceptor-Gq signaling is upregulated in the failing myocardium to increase the myofibrillar Ca2+ sensitivity mainly through the RhoA-Rho kinase pathway rather than through the protein kinase C pathway.
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http://dx.doi.org/10.1152/ajpheart.2001.281.2.H637 | DOI Listing |
J Sci Food Agric
January 2025
College of Food Science and Engineering, Wuhan Polytechnic University, Wuhan, China.
Background: The quality of Acipenser sinensis deteriorates significantly during frozen storage due to its high water, protein, and unsaturated fatty acid content. Conventional freezing methods are insufficient to preserve it effectively. This study investigated the effects of liquid nitrogen freezing (LNF) on the quality and myofibrillar protein (MP) characteristics of A.
View Article and Find Full Text PDFMeat Sci
March 2025
School of Food Science and Engineering, South China University of Technology, Guangzhou 510641, China. Electronic address:
This study aimed to investigate the performance differences of low-sodium myofibrillar protein (MP) gels substituted by different chloride salt mixtures from the perspective of gelation process. The results revealed that low-sodium MP substituted by KCl/CaCl exhibited higher turbidity and particle size at 40 % substitution, and formed protein aggregates earlier at 53 °C. During the gelation process, KCl/CaCl increased the extent of cross-linking as the substitution level increased from 10 % to 40 %, which was prone to forming final gels with poor palatability.
View Article and Find Full Text PDFbioRxiv
November 2024
Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
J Sci Food Agric
November 2024
Department of Food Science and Engineering, College of Food and Pharmacy, Zhejiang Ocean University, Zhoushan, China.
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View Article and Find Full Text PDFCryobiology
December 2024
College of Food Science and Technology, Shanghai Ocean University, Shanghai, China; Key Laboratory of Aquatic Products High Quality Utilization, Storage and Transportation (Co-construction By Ministry and Province), Ministry of Agriculture and Rural Affairs, Shanghai, China; National Experimental Teaching Demonstration Center for Food Science and Engineering, Shanghai Ocean University, Shanghai, China; Shanghai Engineering Research Center of Aquatic Product Processing and Preservation, Shanghai, China; Shanghai Professional Technology Service Platform on Cold Chain Equipment Performance and Energy Saving Evaluation, Shanghai, China. Electronic address:
Temperature abuse occurs frequently during transportation and frozen storage, which affects the quality of frozen aquatic products. Recrystallization generated by temperature abuse leads to irreversible damage to the muscle tissue and microstructure, and exacerbates undesirable oxidation reactions, thus reducing the quality of frozen aquatic products. In this study, a modeling system of temperature abuse alternating between -24 °C and -7 °C was established to evaluate the effect of temperature abuse on the stability of frozen large yellow croaker.
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