Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The expression levels of P2X purinergic receptors were determined in the myometrium of pregnant rats using the quantitative real-time reverse transcriptase polymerase chain reaction (RT-PCR). The messenger RNAs (mRNAs) of P2X4 and P2X7 were expressed most strongly. The expression levels of these receptors increased during the late stages of pregnancy; at the time of delivery, the mRNA levels of P2X4 and P2X7 had increased to 1.9 and 3.2 times the day 19 values, respectively. We also explored the roles of P2X receptors in hormone-induced and inflammation-induced preterm delivery models. In the former, mifepristone caused the P2X4 and P2X7 mRNA levels to increase to 2.1 and 4.1 times the control values, respectively. In the latter, lipopolysaccharide (LPS) caused the mRNA levels of P2X4 and P2X7 to increase dramatically to 7.4 and 18.6 times the control values, respectively. These findings suggest that increased P2X4 and P2X7 receptor expression in pregnant rats is related to uterine contraction leading to term and preterm delivery.
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PMID:Enhanced expression of P2X4 and P2X7 purinergic receptors in the myometrium of pregnant rats in preterm delivery models. 1976 40

Purinergic inhibitory neuromuscular transmission plays an important role in the control of intestinal motility. In most tissues this neurotransmission is apamin-sensitive, but recent studies in human colonic circular smooth muscle (CSM) suggest the presence of apamin-insensitive purinergic inhibitory junction potentials (IJPs). The current studies used conventional intracellular recordings on colonic CSM strips to characterize the purinergic IJPs in murine colonic CSM. P2Y1 receptor expression was examined by using reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry. The IJP induced by nerve stimulation (NS) of one and four pulses in neuronal nitric-oxide synthase knockout mice consists of an apamin-sensitive and a dominant apamin-resistant component. These are identical to the IJPs in wild-type and CD1 mice in the presence of N(omega)-nitro-l-arginine methyl ester (200 microM) and were significantly inhibited by alpha,beta-methylene ATP (50 microM), an analog of ATP. IJPs were not affected by the P2X receptor antagonist 2',3'-o-(2,4,6-trinitrophenyl)-ATP (10 microM). Furthermore, apamin-resistant IJPs induced by single-pulse NS were abolished by pyridoxal-phosphate-6-azophenyl-2',4'-disulfonate (100 microM), a P2 receptor antagonist; 2'-deoxy-N6-methyl adenosine 3,5-diphosphate (MRS-2179; 10 microM), a selective P2Y1 receptor antagonist; and tetrodotoxin (1 microM). Aboral NS induced apamin-sensitive purinergic IJPs, whereas oral and circumferential NS produced apamin-sensitive and -resistant IJPs, with the latter predominating. RT-PCR and immunohistochemistry confirmed the presence of P2Y1 receptors on smooth muscle and in the myenteric plexus. These data suggest that, depending on stimulus location, activation of P2Y1 receptors produces both apamin-sensitive and apamin-resistant IJPs in murine colonic CSM.
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PMID:P2Y1 receptors mediate apamin-sensitive and -insensitive inhibitory junction potentials in murine colonic circular smooth muscle. 2010 87

Release of arginine vasopressin (AVP) from magnocellular neurosecretory cells (MNCs) of the supraoptic nucleus (SON) is controlled by the electrical activity of these neurons. ATP plays a crucial role in the regulation of SON MNCs by activating the purinergic P2X and P2Y receptors. Recent reports of interaction between P2X receptors and pannexin channels have provided new insights into the physiology of the central nervous system; however, the function of pannexin channels has not been assessed in AVP neurons. In the present study, we examined the possible contribution of the pannexin channel in ATP-induced responses in SON AVP neurons. We used the whole-cell patch-clamp technique in isolated rat SON MNCs that express an AVP-enhanced green fluorescent protein transgene. The ATP-induced current was inhibited in a concentration-dependent manner by pannexin channel blockers carbenoxolone and mefloquine, whereas the connexin channel blockers flufenamic acid and lanthanum had no effect. Multi-cell reverse transcriptase-polymerase chain reaction experiments confirmed the existence of pannexin-1 mRNA in AVP neurons. The involvement of the ATP-activated transient receptor potential vanilloid and acid-sensing ion channels was excluded. These results suggest that pannexin channels in SON AVP neurons are involved in the regulatory mechanisms of neuronal activity.
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PMID:Possible contribution of pannexin channel to ATP-induced currents in vitro in vasopressin neurons isolated from the rat supraoptic nucleus. 2153 56


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