Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1323099 (sympathomimetic)
 2,957 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Isolated rat lung parenchymal strips responded to carbachol, 5-HT and phenylephrine (PE) with contractions. Bradykinin (BK), histamine, PGF2 alpha, PGE1, PGE2 and dimaprit were either inactive or produced weak relaxations. Isoproterenol, noradrenaline (NA) and epinephrine (E) relaxed lung strips. The further increase in their concentrations produced contractions of varying magnitudes. The lung strips contracted to 5-HT or carbachol, responded to isoproterenol and E and NA with relaxations. Metiamide and cimetidine (selective histamine H2-receptor antagonists) did not alter responses to histamine and carbachol. Propranolol (a beta-adrenoceptor blocker) antagnoized or reversed relaxations to E and isoproterenol, and markedly enhanced contractions to NA, PE and E. Atropine and phentolamine or dibenzyline antagonized contractions to carbachol and sympathomimetic agents, respectively. From study it may be concluded that there are alpha- and beta-adrenergic receptors mediating contractions and relaxations in the peripheral airways of rat.
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PMID:Evidence for the existence of alpha-adrenoceptors in the rat lung. 22 16

The canine posterior vena cava was excised and divided into three embryologically distinct segments: segment A (supradiaphragm), segment B-C (intrahepatic and that between liver and renal veins), and segment D (infrarenal). Circular and longitudinal strips were cut from each segment, suspended in Krebs bicarbonate solution and isometric tensions were recorded. The responses to six vasoactive agents, as well as transmural neural stimulation were studied. Maximum tension and ED50 were obtained for norepinephrine, epinephrine, acetylcholine, bradykinin, histamine and 5-hydroxytryptamine (5-HT). The responses were not only quantitatively, but qualitatively different among the three segments. Bradykinin constricted the strips in A and B-C but not in D. 5-HT (less than 10(-5) M) caused a dose-dependent contraction in A and D through its direct stimulating action, while in C, a contractile response appeared only after administration of a higher dose of 5-HT. This was due to an indirect sympathomimetic action of the agent. Segment B-C, which histologically contained massive longitudinal muscle bundles in the outer layer of the wall, exhibited spontaneous, rhythmic contractions. The existence of a cholinergic excitatory innervation, in addition to adrenergic, was demonstrated in C by transmural neural stimulation.
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PMID:Differences in the response of three embryologically distinct segments of the isolated canine posterior vena cava to vasoactive substances. 63 Jan 30