Adenosine plays an important role in regulation of renal microcirculation. All receptors of adenosine, A1, A2A, A2B, and A3, have been found in the kidney. However, little is known about the location and function of the A3 receptor in the kidney. The present study determined the expression and role of A3 receptors in mediating the afferent arteriole (Af-Art) response and studied the interaction of A3 receptors with angiotensin II (ANG II), A1 and A2 receptors on the Af-Art. We found that the A3 receptor expressed in microdissected isolated Af-Art and the mRNA levels of A3 receptor were 59% of A1. In the isolated microperfused Af-Art, A3 receptor agonist IB-MECA did not have a constrictive effect. Activation of A3 receptor dilated the preconstricted Af-Art by norepinephrine and blunted the vasoconstrictive effect of both adenosine A1 receptor activation and ANG II on the Af-Art, respectively. Selective A2 receptor antagonist (both A2A and A2B) had no effect on A3 receptor agonist-induced vasodilation, indicating that the dilatory effect of A3 receptor activation is not mediated by activation of A2 receptor. We conclude that the A3 receptor is expressed in the Af-Art, and activation of the A3 receptor dilates the Af-Art.
Vanishing lung syndrome, also known as idiopathic giant bullous emphysema, is a rare disease characterized by giant emphysematous bullae. The disease is diagnosed by radiological findings of giant bullae in one, or both, of the upper lobes of the lung, occupying at least one-third of the hemithorax. There have been several reports of vanishing lung syndrome, however it remains to be determined whether genetic inheritance is associated with the disease. In the present study, five patients within one family, with vanishing lung syndrome, were reported during a follow-up period of ~ 20 years. All of the patients were diagnosed by radiological findings, which showed diffuse bullae in the lungs, which were of varying size and asymmetrical distribution, and the occurrence of pneumothorax or emphysema. The Medical Ethics Committee of the People's Hospital of Zhangye Municipality (Zhangye, China) approved this study, and all subjects gave their informed consent During the follow-up period of 20 years, bullae in these patients were shown to progressively increase, and no other pulmonary diseases, including lung cancer, tuberculosis, pneumoconiosis and chronic bronchitis were observed. Autosomal dominant inheritance was observed in five cases, and autosomal recessive inheritance was observed in one case. The present study suggests that vanishing lung syndrome may be associated with autosomal dominant and recessive genetic inheritance.
Magnetic field-assisted magnetic compound fluid (MCF) ultra-precision machining technology is regarded as an effective method to obtain a smooth surface. However, due to the evaporation and splashing of water in the polishing fluid during processing, the service life of the MCF slurry is reduced. This paper presents a material removal model for MCF polishing, and a novel experimental apparatus is proposed to extend the service life by supplying MCF components into the MCF slurry. Firstly, in order to obtain the ideal polishing tool, the appearance morphologies and the formation process of the MCF slurry were observed by an industrial camera. On this basis, the optimum parameters were determined by multi-factor and multi-level orthogonal experiments. Finally, the investigation of the MCF service life was carried out under the optimal processing parameters. The main findings are summarized as follows. (1) Excellent MCF polishing tools are obtained when the eccentric distance r is 4 mm and the MCF slurry supply V is 1 mL. (2) When the eccentric distance increases from 2 mm to 4 mm, the forming time of the MCF tool decreases sharply, but when the eccentricity exceeds 4 mm, the decreasing trend becomes slow. The molding time grows steadily as the supply is increased. (3) When the machining gap Δ, the MCF carrier speed nc, the eccentricity r, and the revolution speed of magnetic nm are 1 mm, 500 rpm, 4 mm, and 600 rpm, respectively, the ideal machining effect can be obtained. (4) It could be proven that the polishing device is feasible to extend the service time of the MCF slurry by adding MCF components.
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