Michiko Oshita

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The subtypes of alpha1-adrenoceptor are coexpressed in many tissues. We examined the relationship between coexpressed alpha1-adrenoceptor subtypes and their functions in blood vessels. Rat and rabbit aortas coexpressed three subtypes (alpha1A, alpha1B, alpha1D) and four subtypes (alpha1A, alpha1B, alpha1D, alpha1L), respectively. In rat aorta however,(More)
1. We examined whether alpha 1-adrenoceptors in various blood vessels can be divided into subtypes by antagonist affinity or by susceptibility to chloroethylclonidine or nifedipine. 2. Noradrenaline or phenylephrine produced concentration-dependent contractions in all the tissues tested, which were competitively inhibited by phentolamine, yohimbine,(More)
OBJECTIVE To characterize the alpha 1-adrenoceptor subtypes of the human benignly enlarged prostate using functional and binding studies. MATERIALS AND METHODS Strips of prostatic tissue taken from nine patients with benign prostatic hypertrophy who were undergoing open prostatectomy were used in the study. RESULTS The strips isolated from five(More)
We have cloned a cDNA encoding rabbit alpha 1d-adrenoceptor from the rabbit liver cDNA library. The deduced amino-acid sequence of this clone encodes a protein of 576 amino acids that shows strong sequence homology to previously cloned human, rat and mouse alpha 1d-adrenoceptors. The pharmacological radioligand binding properties of this clone expressed in(More)
1. beta-Adrenoceptor subtypes in rat and rabbit urinary bladder were investigated in functional experiments by use of several agonists and antagonists. 2. All agonists tested produced concentration-dependent relaxation, but the relative potencies varied between both species: BRL 37344 (pD2:8.0) > isoprenaline (7.3) > adrenaline (6.7) = noradrenaline (6.6)(More)
1. The putative alpha 1-adrenoceptor subtypes of rat cerebral cortex membranes were characterized in binding. 2. Specific binding of [3H]-prazosin was saturable between 20-5000 pm. Scatchard plots of the binding data were non-linear, indicating the presence of two distinct affinity sites for prazosin (pKD, high = 10.18, Rhigh = 308 fmol mg-1 protein; pKD,(More)
1. alpha 1-Adrenoceptor subtypes in rabbit thoracic aorta have been examined in binding and functional experiments. 2. [3H]-prazosin bound to two distinct populations of alpha 1-adrenoceptors (pKD,high = 9.94, Rhigh = 79.2 fmol mg-1 protein; pKD,low = 8.59, Rlow = 215 fmol mg-1 protein). Pretreatment with chloroethylclonidine (CEC, 10 microM) almost(More)
1. Electrical transmural stimulation evoked a sympathetic contraction in the isolated dog mesenteric artery. This contraction consisted of adrenergic and purinergic components, which were separately observed under conditions where postjunctional P2 purinoceptors were desensitized with alpha, beta-methylene ATP or postjunctional alpha 1 adrenoceptors were(More)
A cDNA clone, which has an open reading frame of 1398 nucleotides encoding a 466-amino-acid peptide, has been isolated from rabbit liver cDNA library. Compared with the peptide sequence, it shows high homology to alpha1a adrenoceptors of human, bovine and rat. We expressed this clone in COS-7 and investigated the pharmacological properties, revealing(More)
BACKGROUND The vascular responsiveness of nasal mucosa has been determined frequently by using isolated mucosal tissues although it is not clear whether the response of the whole tissue truly reflects the response of the vasculature (especially veins) in mucosa. In this study, the in vivo responsiveness of mucosal veins was compared with in vitro(More)