• Clinical and Experimental Reproductive Medicine
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• 제27권2호
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• pp.133-144
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• 2000

Objective: Several water channels (aquaporins; AQP) that belong to the MIP (major intrinsic protein) family have identified. In the selected tissues including red blood cells or renal tubules, water movements are abundant and/or physiologically important. Unexpectedly, a high water permeability of human and ram sperm has been reported. Recent studies showed that AQP7 and AQP8 are present in testes, so that the high water permeability of human sperm suggested to be mediated by AQPs. Method: To identify the identity of aquaporins expressed in testes, RT-PCR was performed using degenerative primers, which were designed to correspond to highly conserved sequences surrounding the Asn-Pro-Ala (NPA) motifs in the aquaporins. New expressed AQP series were reconfirmed by immunohistochemical study using rabbit polyclonal antibodies. Results: DNA sequencing of PCR products revealed that AQP2 and AQP3 mRNA as well as AQP7 and AQP8 are expressed in human and rat testes. In human and rat testes, AQP2 are expressed in spermatozoa, interstitial cells and myofibroblasts and AQP3 are expressed in myofibroblasts of semineferous tubules on immunocytochemical stain. Conclusion: These results indicate that multiple aquaporins are expressed in testes, and that they may have important roles in the spermatogenesis and the germ cell function of testis.

• 한국발생생물학회지:발생과생식
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• 제26권2호
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• pp.59-69
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• 2022

Many efforts have been made to study the expression of aquaporins (AQP) in the mammalian reproductive system, but there are not enough data available regarding their localized expression to fully understand their specific roles in male reproduction. The present study investigated the expression and localization patterns of different AQP subtypes in the adult mouse testes and testicular spermatozoa using an immunofluorescence assay. All the studied AQPs were expressed in the testes and revealed subtype-specific patterns in the intensity and localization depending on the cell types of the testes. AQP7 was the most abundant and intensive AQP subtype in the seminiferous tubules, expressing in Leydig cells and Sertoli cells as well as all stages of germ cells, especially the spermatids and testicular spermatozoa. The expression pattern of AQP3 was similar to that of AQP7, but with higher expression in the basal and lower adluminal compartments rather than the upper adluminalcompartment. AQP8 expression was limited to the spermatogonia and Leydig cells whereas AQP9 expression was exclusive to tails of the testicular spermatozoa and elongated spermatids. Taken together, the abundance and distribution of the AQPs across the different cell types in the testes indicating to their relavance in spermatogenesis, as well as in sperm maturation, transition, and function.

• The Korean Journal of Physiology and Pharmacology
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• 제7권3호
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• pp.181-185
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• 2003

Whether there exists a sympathetic neural regulation on the aquaporin (AQP) channels in the kidney was examined. Male Sprague-Dawley rats were used. They were renal nerve denervated by stripping the nervous and connective tissues passing along the renal artery and vein, and painting these vessels with 10% phenol solution through a midline abdominal incision. Three days later, the expression of AQP1-4 proteins in the denervated kidneys was determined. The content of norepinephrine was found significantly decreased following the denervation. Accordingly, the expression of AQP2 proteins was markedly decreased. The expression of AQP3 and AQP4 was also slightly but significantly decreased, while that of AQP1 was not. Neither the basal nor the AVP-stimulated accumulation of cAMP was significantly affected in the denervated kidney. It is suggested that the sympathetic nervous system has a tonic stimulatory effect on AQP channels in the kidney.

• The Korean Journal of Physiology and Pharmacology
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• 제7권2호
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• pp.97-101
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• 2003

The salivary glands produce 1.5L of fluid per day. As in other exocrine organs, the general mechanism in the salivary glands is that water movement occurs secondary to osmotic driving forces created by active salt transport. Therefore, high water permeability in the salivary glands is expected to have a variety of aquaporin (AQP), a water channel. Although some AQPs have been known to be present in the salivary glands, roles of parasympathetic nerve in AQP expression have not yet been examined. This study was designed to examine the changes of AQPs and extracellular signal-regulated kinase (ERK) in the submandibular glands after parasympathetic denervation. Right chorda-lingual nerve was cut, and each right (experiment) and left (control) submandibular gland was excised at 1, 3, 7, 14, 30 days after denervation. The denervated right submandibular glands were resulted in weight loss and morphologic changes, including cell loss and atrophy, as the time elapsed after parasympathetic denervation increased, whereas there were no histologic alteration in control side. AQP5 which is known to reside in apical membrane and secretory caraliculi of the submandibular acini were gradually underexpressed according, as the time after denervation increased. Expression of AQP4 in submandibular ductal epithelium was down-regulated after denervation. Besides, AQP3 and 8, which is known to be present in basolateral membrane of the glandular acini, were gradually underexpressed after denervation, similar to the pattern of other types. Expression of ERK, a mitogen-activated protein kinase, was downregulated after parasympathetic denervation in the submandibular gland. These results suggest that parasympathetic nervous system regulates the expression of AQPs in salivary glands, and is in part mediated by ERK pathway.

• Asian Pacific Journal of Cancer Prevention
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• 제13권5호
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• pp.1971-1975
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• 2012

Overexpression of several aquaporins (AQPs) has been reported in different types of human cancer but their role in carcinogenesis, for example in the cervix, have yet to be clearly defined. In this study, expression of AQPs in cervical carcinomawas investigated by real-time PCR, immunofluorescent and immunohistochemical assays and evaluated for correlations with clinicopathologic variables. AQP1, 3, 8 exhibited differential expression in cervical carcinoma, corresponding CIN and mild cervicitis. AQP1 was predominantly localized in the microvascular endothelial cell in the stroma of mild cervicitis, CIN and cervical carcinoma. AQP3 and AQP8 were localized in the membrane of normal squamous epithelium and carcinoma cells, local signals being more common than diffuse staining. AQP1 and AQP3 expression was remarkably stronger in cervical cancer than in mild cervicitis and CIN2-3 (P<0.05). AQP8 expression was highest in CIN2-3 (91.7%), but levels in cervical carcinoma were also higher than in mild cervicitis. AQP1, AQP3, AQP8 expression significantly increased in advanced stage, deeper infiltration, metastatic lymph nodes and larger tumor volume (P<0.05). Our findings showed that AQPs might play important roles in cervical carcinogenesis and tumour progression in Uygur women.

• The Korean Journal of Physiology and Pharmacology
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• 제1권5호
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• pp.495-504
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• 1997

Water transport is mediated by two distinct pathways, diffusional and channel-mediated water transport. The first molecular water channel was identified from human erythrocytes in 1992. Genetically-related proteins from other mammalian tissues have subsequently been identified to transport water, and the group is referred to as th "Aquaporins". Aquaporin-4 (AQP4) is most abundant in the brain, which may be involved in CSF reabsorption and osmoregulation. However, ontogeny and regulatory mechanisms of AQP4 channels have not been reported. Northern blot analysis showed that AQP4 mRNA began to be expressed in the brain just before birth and that its expression gradually increased by PN7 and then decreased at adult level. AQP4 was expressed predominantly in the ependymal cells of ventricles in newborn rats. And then its expression decreased in ependymal cells and increased gradually in other regions including supraoptic and paraventricular nuclei. AQP4 is also expressed in the subfornical organ, in which the expression level is not changed after birth. Cryogenic brain injury did not affect expression of AQP4 mRNA, while ischemic brain injury decreased it. Osmotic water permeability of AQP4 channel expressed in Xenopus oocytes was inhibited by the pretreatment of BAPTA/AM and calmidazolium, a $Ca^{2+}/Calmodulin$ kinase inhibitor, in a dose-dependent manner. These results indicate that the expression and the function of AQP4 channel are regulated by developmental processes and various pathophysiological conditions. These results will contribute to the understanding of fluid balance in the central nervous system and the osmoregulatory mechanisms of the body.

• Tuberculosis and Respiratory Diseases
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• 제60권3호
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• pp.330-336
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• 2006

배 경: 급성폐손상은 여러 가지 치료의 발전에도 높은 사망률을 보이는 질환으로 병태생리학적 연구가 필요한 실정이다. 아쿠아포린 (AQP)은 수분통로로 급성폐손상에서 폐부종에 관여되는 것으로 알려져 있어 bleomycin을 이용한 급성 폐손상모델에서 아쿠아포린의 발현을 확인하고자 하였다. 방 법: Bleomycin 10 U/kg을 Sprague-Dawley rats에 흡입시켜 급성 폐손상 보델을 만들고 흡입후 4, 7, 14일에 호흡수, 상시호흡량을 측정하고, 기관지폐포세척액을 얻으며, 폐조직을 얻었다. 얻은 폐조직에서 wet/dry 량을 측정하고 기관지 폐포세척액에서 사이토카인, 산화질소산물(nitrite와 nitrate)등을 측정하였다. 그리고 폐조직에서 AQP1, AQP4와 AQP5를 면역조직염색에서 확인하였다. 결 과: Bleomycin 흡입 후 호흡수는 4, 7일에 상시호흡량은 4일에 대조군에 비해 유의한 차이를 보였다. Wet/dry 질량은 대조군에 비해 4일에 유의하게 높았다. 기관지폐포세척액에서 산화질소산물은 4일에 가장 높았다. 면역화학염색에서 AQP1과 AQP4는 4일에 감소하였으며 AQP4는 7일에 증가하였고, AQP5는 4, 7, 14일에 발현이 증가하였다. 결 론: 아쿠아포린은 급성폐손상 모델에서 다양하게 발현하여 급성 폐손상의 경과에 따라 다르게 작용함을 시사한다.