Upregulation of ppET-1/ETBR/eNOS mRNA Expression After Calcitriol Treatment in Chronic Kidney Diseases Model in Rats

@#Introduction: Myofibroblast formation in the interstitial area is the hallmark of chronic kidney disease (CKD). Endothelin signalling has been known to play role in physiology and pathophysiology in the kidney. Vitamin D has a reno-protective effect through inhibiting inflammation and fibrosis. However, the interaction between vitamin D and endothelin signalling in the CKD model has not been elucidated yet. Therefore, we aimed to check the difference impact of endothelin (ET) receptor in CKD. Methods: Sprague Dawley rats (3-months-old, 150-250grams) underwent 5/6 subtotal nephrectomy (SN) to induce CKD. Then, it was divided into 4 groups (each contains 6 rats): sham operation (SO), 5/6 subtotal nephrectomy (SN), calcitriol groups (0.01µg/100grBW/day (SN-D1), and 0.05µg/100grBW/day (SN-D2). Calcitriol was administered for 14 days after the surgery. The Sham Operation (SO) group was injected with NaCl. At the specified date, the rats were sacrificed and the kidneys were harvested. Fibrosis was quantified based on Sirius Red staining. Immunostaining was done for localizing fibroblast (PDGFRβ). The mRNA expressions of prepro-ET-1, endothelin receptor A (ETAR), endothelin receptor B (ETBR), and endothelial nitrite oxide synthase (eNOS) were quantified using reverse-transcriptase PCR (RT-PCR). Results: The CKD promotes an elevation of prepro-ET-1, ETBR, and eNOS, and reduction of ETAR (p<0.05) mRNA expression compared to the SO group. Administration of calcitriol (SN-D1 and SN-D2) showed the vice versa effects. However, only SN-D2 group consistently showed statistically significant differences whenever compared to either SO or SN groups. Conclusion: Calcitriol might attenuate interstitial fibrosis in CKD model via ET-1/eNOS signalling.

Expression profile of endothelin receptors (ETA and ETB) and microRNAs-155 and -199 in the corpus cavernosum of rats submitted to chronic alcoholism and diabetes mellitus

Recent evidence shows that chronic ethanol consumption increases endothelin (ET)-1 induced sustained contraction of trabecular smooth muscle cells of the corpora cavernosa in corpus cavernosum of rats by a mechanism that involves increased expression of ETA and ETB receptors. Our goal was to evaluate the effects of alcohol and diabetes and their relationship to miRNA-155, miRNA-199 and endothelin receptors in the corpus cavernosum and blood of rats submitted to the experimental model of diabetes mellitus and chronic alcoholism. Forty-eight male Wistar rats were divided into four groups: control (C), alcoholic (A), diabetic (D), and alcoholic-diabetic (AD). Samples of the corpus cavernosum were prepared to study the protein expression of endothelin receptors by immunohistochemistry and expression of miRNAs-155 and -199 in serum and the cavernous tissue. Immunostaining for endothelin receptors was markedly higher in the A, D, and AD groups than in the C group. Moreover, a significant hypoexpression of the miRNA-199 in the corpus cavernosum tissue from the AD group was observed, compared to the C group. When analyzing the microRNA profile in blood, a significant hypoexpression of miRNA-155 in the AD group was observed compared to the C group. The miRNA-199 analysis demonstrated significant hypoexpression in D and AD groups compared to the C group. Our findings in corpus cavernosum showed downregulated miRNA-155 and miRNA-199 levels associated with upregulated protein expression and unaltered mRNA expression of ET receptors suggesting decreased ET receptor turnover, which can contribute to erectile dysfunction in diabetic rats exposed to high alcohol levels.

Contractile Responses to Endothelins in Isolated Arteries from Human Uterus / 대한산부인과학회잡지

OBJECTIVE: We examined the vasoconstricting poperties of endothelin (ET) on isolated arteries from pregnant as well as non-pregnant uterus. METHODS: Arteries of the uterus were obtained from both hysterectomized uterus and during pregnany hysterectomy for control group and cesarean section for pregnant group. Rings of uterine artery were suspended on muscle chambers at their optimal length for generating tension and contractile properties were examined. RESULTS: ET-1 and ET-2 induced concentration-dependent constriction of both isolated arterial strips from non-pregnant and pregnant uterus. The contraction to ET-1 and ET-2 were more enhanced in full-term pregnancy. Furthermore, in pregnant group, sarafotoxin S6c and IRL 1620, ET. agonists, induced a dose-dependent contraction, which was not shown in those from non-pregnant human. Pretreatment of human uterine arterial strips from pregnant uterus with BQ610, an ET. antagonist, for 10 min resulted in a dose-related rightward shift of ET-1 response curve with diminution of maximal response. Schild plot analysis yielded a pA value of 7.29 with a slope of 0.98. However, BQ788, an ET antagonist, did not produce any rightward shift. The contraction to lower concentration (10-8~3*10-7 M) of sarafotoxin S6c was not affected by BQ788, whereas that to higher concentration (10-s-8*10-7 M) was marked diminished. However, BQ610 did not exnt any efFect on sarafotoxin S6c-induced contraction in arterial staips from pregnant uterus. When the bath solution was replaced with Ca-free physiological salt solution (PSS) containing 1 mM EGTA for 10 min prior to adding sarafotoxin S6c, sarafotoxin S6c-induced contraction was completely abolished. Sarafotoxin S6c (10 nM)-induced contraction was prefetentially blocked by a protein kinase C antagonist, H-7, whereas it was less sensitive to a calmodulin antagonist, calmidazolium, CONCLUSION: Based on above results, we concluded that ET plays an important role in regulating uterine blood flow through the activation of ETa and ETB receptors. Furthermote, ETB receptors may predominantly contribute to the modulation of human uterine circulation in full-term pregnancy.