Molecular cloning and functional expression of the guinea pig alpha(1a)-adrenoceptor

An extract from wax apple (Syzygium samarangense (Blume) Merrill and Perry) effects glycogenesis and glycolysis pathways in tumor necrosis factor-α-treated FL83B mouse hepatocytes

FL83B mouse hepatocytes were treated with tumor necrosis factor-α (TNF-α) to induce insulin resistance to investigate the effect of a wax apple aqueous extract (WAE) in insulin-resistant mouse hepatocytes. The uptake of 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxyglucose (2 NBDG), a fluorescent D-glucose derivative, was performed, and the metabolism of carbohydrates was evaluated by examining the expression of glycogenesis or glycolysis-related proteins in insulin-resistant hepatocytes. The results show that WAE significantly improves the uptake of glucose and enhances glycogen content in insulin-resistant FL83B mouse hepatocytes. The results from Western blot analysis also reveal that WAE increases the expression of glycogen synthase (GS), hexokinase (HXK), glucose-6-phosphate dehydrogenase (G6PD), phosphofructokinase (PFK) and aldolase in TNF-α treated cells, indicating that WAE may ameliorate glucose metabolism by promoting glycogen synthesis and the glycolysis pathways in insulin-resistant FL83B mouse hepatocytes.

Four different ways of alternative transcripts generation mechanism in ADRA1A gene

The ADRA1A (Alpha-1-adrenergic receptor) gene is one of the members of G protein-coupled receptor superfamily. Alternative splicing of this gene was known to generate four transcript variants which code four isoforms with various C-terminal regions. In this study, we conducted expression analysis and evolutionary characterization of alternative transcripts of the ADRA1A gene. In total, 10 alternative transcripts were identified using experimental approaches and in silico analysis. Among them, 6 alternative transcripts (T1, T2, T3, T4, T4-1, and T8) were validated by RT-PCR approaches and sequencing procedures. From the alternative splicing analysis, it could be assumed that there were three different alternative transcripts generation mechanisms and unknown mechanism. First one is the integration event of three different TEs (AluSc, L1MC5, and MIR3) as seen on the last exons of T3, T4, T4-1, T5, T6, and T7 transcripts. The second mechanism is a differential promoter usage on T8. The third one is a substitution event of the 3' splicing site during the primate evolution on T3. The last one is an unknown mechanism which was identified in the T4-1 transcript. Therefore, alternative transcripts of human ADRA1A gene occurred by four different ways, such as integration of TEs, differential promoter usage, substitution of splicing sites, and unknown mechanism.

Expression and function of G-protein-coupled receptorsin the male reproductive tract

This review focuses on the expression and function of muscarinic acetylcholine receptors (mAChRs), α1-adrenoceptors and relaxin receptors in the male reproductive tract. The localization and differential expression of mAChR and α1-adrenoceptor subtypes in specific compartments of the efferent ductules, epididymis, vas deferens, seminal vesicle and prostate of various species indicate a role for these receptors in the modulation of luminal fluid composition and smooth muscle contraction, including effects on male fertility. Furthermore, the activation of mAChRs induces transactivation of the epidermal growth factor receptor (EGFR) and the Sertoli cell proliferation. The relaxin receptors are present in the testis, RXFP1 in elongated spermatids and Sertoli cells from rat, and RXFP2 in Leydig and germ cells from rat and human, suggesting a role for these receptors in the spermatogenic process. The localization of both receptors in the apical portion of epithelial cells and smooth muscle layers of the vas deferens suggests an involvement of these receptors in the contraction and regulation of secretion.

Blockade of alpha1 adrenoreceptors in the dorsal raphe nucleus prevents enhanced conditioned fear and impaired escape performance following uncontrollable stressor exposure in rats

Previous research has shown that the effect of exposure to uncontrollable stressors on conditioned fear responding and escape behavior in rats is dependent on serotonergic neural activity in the dorsal raphe nucleus (DRN). The role that norepinephrine released in the DRN plays in producing the behavioral consequences of exposure to inescapable tail shock in rats was investigated in the present study. The selective alpha1 adrenoreceptor antagonist benoxathian was injected into the DRN before exposure to inescapable tail shock or before behavioral testing conducted 24 h later. Benoxathian prevented the impairment of escape responding produced by inescapable shock, but did not reverse this effect when given before testing. The enhancement of conditioned fear produced by prior inescapable shock was attenuated by benoxathian administered before inescapable shock or before behavioral testing. These results support the view that noradrenergic input to the DRN is necessary to produce the behavioral effects of inescapable tail shock.