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Patients with pulmonary atresia and ventricular septal defect (PA/VSD) demonstrate a wide variety of pulmonary and coronary arteries; additionally, coronary pulmonary artery fistula (CPAF) is a rare manifestation of PA/VSD and is seldom detected during pregnancy. In this report, we present a case of prenatal diagnosis of CPAF in PA/VSD with showing the present impactful images of CPAF in a neonate, which were obtained by using fetal echocardiography and postnatal electrocardiography-gated 320-row computed tomography. Prenatal diagnosis of CPAF can facilitate the provision of better therapeutic strategies after birth.

We recently found a constitutively active mutant of natriuretic peptide receptor 2 (caNPR2; V883M), which synthesizes larger amounts of cyclic guanosine monophosphate (cGMP) intracellularly without any ligand stimulation than existing drugs. The aim of this study was to investigate the therapeutic effects of gene transduction using caNPR2 for pulmonary arterial hypertension (PAH). In vitro gene transduction into human pulmonary arterial smooth muscle cells using Sendai virus (SeV) vectors carrying caNPR2 induced 10,000-fold increases in the synthesis of cGMP without ligand stimulation, and the proliferation of caNPR2-expressing cells was significantly attenuated. The PAH model rats generated by hypoxia and the administration of SU5416 were then treated with SeV vectors through a direct injection into the left pulmonary artery. Right ventricular systolic pressure was significantly decreased 2 weeks after the treatment, while systemic blood pressure remained unchanged. Histological analyses revealed that the medial wall thickness and occlusion rate of pulmonary arterioles were significantly improved in caNPR2-treated lungs. Neither the systemic integration of virus vectors nor side effects were observed. The massive stimulation of cGMP synthesis by gene therapy with caNPR2 was safe and effective in a PAH rat model and, thus, has potential as a novel therapy for patients with severe progressive PAH.

Our previous in vivo experiment demonstrates that chronic morphine treatment up-regulates diazepam binding inhibitor (DBI) transcripts in mouse cerebral cortex, although detailed mechanisms were unclear (Katsura et al. [1998] J. Neurochem. 71:2638-2641). This study sought to elucidate the precise mechanisms of DBI mRNA up-regulation by long-term treatment with morphine using primary cultures of mouse cerebral cortical neurons. A significant increase in DBI mRNA was observed after sustained exposure to 0.3 microM morphine for 2 days, and the maximal expression occurred after 2 days of exposure, whereas transient exposure to 0.3 microM morphine for 15 min, 1 hr, and 3 hr produced no changes in the expression. Continuous exposure to DAMGO also significantly increased DBI mRNA expression, which was completely abolished by a selective antagonist of mu-opioid receptors, beta-funaltrexamine (beta-FNA). The morphine-induced increase in DBI mRNA expression and its content were completely inhibited by naloxone and beta-FNA, and the inhibitory potential of naloxonazine was about half that of beta-FNA. On the other hand, kappa- and delta-opioid receptor antagonists showed no effects on the morphine-induced increase in DBI mRNA. In addition, both a calmodulin antagonist and a CaM II kinase inhibitor significantly suppressed the morphine-induced increase in DBI mRNA. These results indicate that the increase in DBI expression is induced by continuous activation of mu-opioid receptors but not of kappa- and delta-opioid receptors and is regulated by the calcium/calmodulin-related phosphorylation system.

Introduction: Type B natriuretic peptide receptor (NPR-B) is one of the transmembrane guanylyl cyclases and synthesizes cGMP on C-type natriuretic peptide binding. We have found a novel constitutively active mutation in the NPR-B gene in a family case showing overgrowth and bone anomalies. Previously, we constructed adenovirus vectors carrying this mutant NPR-B and administered to Sugen PAH rats intratracheally to investigate its therapeutic effect. However, the use of adenovirus vectors actually caused inflammatory host response in the lung. Objective: Sendai virus vector (SeV) is well known for its high transduction efficiency as well as the low toxicity. Recently, the results of a Phase I/IIa clinical study of SeV in human peripheral arterial disease have been reported. The objective of this study was to investigate the therapeutic effect of SeV carrying constitutively active mutant of NPR-B for PAH in rats. Methods and Results: We constructed SeV carrying wild-type (WT), and mutant (Mut) NPR-B. Control SeV carrying Azami-Green was purchased from MBL (Medical & Biological laboratories, Nagoya, Japan). The overexpression of the mutant in human pulmonary artery smooth muscle cells by SeV induced significant increase in cGMP levels (control, 0.193±0.115 pmol/mL; WT-NPR-B, 38.3±29.6 pmol/mL; Mut-NPR-B, 2460±577 pmol/mL; n=3; p In Sugen PAH rats, intravascular administration of SeV carrying Mut-NPR-B significantly decreased right ventricular systolic pressure (Control, 61.4±8.4 mmHg; WT, 61.5±5.4 mmHg; Mut, 46.9±4.9mmHg; n=6; p Conclusions: The CNP/NPR-B signaling pathway is an additional therapeutic target for the treatment of PAH. The enhancement of CNP/NPR-B pathway could ameliorate both intimal and medial remodeling of pulmonary artery in PAH.

We investigated the effect of chronic nicotine administration on high voltage-gated calcium channels (HVCCs) in the mouse cerebral cortex. The treatment significantly increased expression of alpha1C, alpha1D, alpha1F, and alpha2/delta1 subunits with no changes of beta4 subunit of L-type HVCCs. [(3)H]Diltiazem binding to the particulate fractions increased with increased Bmax value. These results indicate that chronic nicotine treatment up-regulates L-type HVCCs, which is due to increased expression of alpha1 and alpha2/delta1 subunits.

We investigated how functional changes in high voltage-gated calcium channels (HVCCs) occurred in the cerebral cortex of mouse with ethanol physical dependence. The continuous treatment of mice with ethanol vapor for 8 days significantly increased the expressions of alpha1C, alpha1D, and alpha2/delta1 subunits of L-type HVCCs in association with decreased level of beta4 subunit of L-type HVCCs, although alpha1A and alpha1B subunits of P/Q- and N-type HVCCs, respectively, showed no alterations. [(3)H]Diltiazem binding to the particulate fractions increased with increased Bmax value and no changes of Kd value. These results indicate that ethanol physical dependence accompanies the up-regulation of L- type HVCCs, which is due to increased expression of alpha1C, alpha1D, and alpha2/delta1 subunits.

Previous reports revealed up-regulation of L-type high voltage-gated calcium channels (HVCCs) in mouse brains with ethanol physical dependence. We investigated mechanisms of enhancement of L-type HVCC function using mouse cerebrocortical neurons exposed to 50 mM ethanol for 3 days and the brains of mouse physically dependent on ethanol. Ethanol facilitated 30 mM KCl-stimulated 45Ca2+ influx in dose- and duration-dependent manners, which was abolished by nifedipine, an inhibitor specific to L-type HVCCs, but not by inhibitors for other types of HVCCs. Increase in [3H]PN200-110 binding to the particulate fractions from the ethanol-treated neurons was due to increased Bmax value with no changes in Kd value. Western blot analysis showed the increased expression of α1C, α1D, and α2/δ1 subunits with decreased β4 subunit expression and no changes in expressions of α1A, α1B, α1F, and α2 subunits. A similar pattern of the changes in the expression of these subunits of L-type HVCCs were observed in the cerebral cortex from mouse with ethanol physical dependence. These results indicate that sustained ethanol exposure to the neurons induces up-regulation of L-type HVCCs, which is due to increased expressions of α1C, α1D, and α2/δ1 subunits, and produces no alterations in P/Q- and N-type HVCC functions. Keywords:: ethanol (alcohol) physical dependence, high voltage-gated calcium channel, Ca2+ influx, [3H]PN200-110 binding, cerebral cortical neuron