Journal of Smooth Muscle Research
Online ISSN : 1884-8796
Print ISSN : 0916-8737
ISSN-L : 0916-8737
35 巻, 4 号
選択された号の論文の3件中1~3を表示しています
  • Michiko IIJIMA, Kayoko AOKI, Junko YAMAMOTO, Yang-Il FANG, Kazutaka MO ...
    1999 年 35 巻 4 号 p. 99-110
    発行日: 1999年
    公開日: 2010/07/21
    ジャーナル フリー
    The methods for isolation of single cells from the guinea pig longitudinal ileum were investigated with focussing on the papain concentration for the digestion of the ileum. The ileal muscle was minced. The minced muscle was loaded with fluorescent probes of calcein or fura-2, and treated with papain for 30 min at various concentrations. Papain at concentrations more than 1 U/ml reduced both calcein fluorescence and fura-2-signal evoked by carbachol. Cabachol-induced fura-2-signal was more sensitive to papain than calcein fluorescence, suggesting that proteins related to the formation of receptors are more vulner able than membrane lipids or proteins limiting the membrane permeability upon the expo sure to papain. The resultant yield of single cells was highest at 0.56 U/ml of papain without affecting calcein and fura-2 fluorescence responses, thus this concentration appeared to be appropriate for the isolation of single cells from the ileum. Single cells alive con tracted dose-dependently by the exposure to carbachol (0.1-10μM) under the microscopic measurement, and were appeared to grow confluent in culture for approximately 15 days. These results suggest that the low concentration, 0.56 U/ml, of papain in the isolation medium is better to obtain functional cells from the guinea pig ileum.
  • Tsutomu MICHIBAYASHI
    1999 年 35 巻 4 号 p. 111-124
    発行日: 1999年
    公開日: 2010/07/21
    ジャーナル フリー
    It is very important to know under medical treatment which kinds of platelet agonists participate in abnormal platelet-blood vessel interactions. The present study, focusing on platelet activating factor (PAF) was undertaken in an attempt to investigate its action on platelet aggregating response and vasocontractile response to noradrenaline (NA-R). We used autologous platelets and isolated perfused arterial segments from Japanese white rabbits. Firstly, typical tracings of platelet aggregating response to PAF were increased in a dose-dependent fashion, which remained constant and long-lasting. Secondly, noradrenaline (NA) at 5 to 25 ng elicited an initially augmented response in the presence of platelet rich plasma (PRP) with PAF, followed by gradually attenuated responses. Based on the light transmission intensity, platelet aggregation did not seem to be directly or strictly linked to vasocontractile response. Pretreatment with either dibutyryl cyclic AMP (DBcAMP) or indomethacin (IM, a cyclo-oxygenase inhibitor) clearly caused reductions in NA-R as well as platelet aggregation in the presence of PRP with collagen, whereas platelet aggregation and NA-R in the presence of PRP with PAF were scarcely influenced by pretreatment with either DBcAMP or IM. Thus, it seems reasonable to conclude that, in contrast to the response to collagen, platelet aggregation response to PAF was almost indifferent to the adenylate cyclase-cyclic AMP system and the cyclo-oxygenase metabolic pathway.
  • Yu-Jing GAO, Yoshitaka NISHIMURA, Aritomo SUZUKI, Hideaki HIGASHINO
    1999 年 35 巻 4 号 p. 125-134
    発行日: 1999年
    公開日: 2010/07/21
    ジャーナル フリー
    The reactivity of intrarenal arteries to vasoconstrictor and vasodilator polypeptides was examined in adult stroke-prone spontaneously hypertensive rats (SHRSP). The contraction response to endothelin-1 (ET-1) was greater in SHRSP than in age-matched Wistar-Kyoto rats (WKY), and so was the pD2 estimate (8.05±0.03in SHRSP, and 7.73±0.06 in WKY; n=5, P<0.05). The contraction response to, and the pD2 estimate of, vasopressin were comparable in SHRSP and WKY. Neuropeptide Y did not contract the intrarenal arteries. In norepinephrine-precontracted arteries with intact endothelium, substance P and neurokinin A did not relax the arteries of either SHRSP or WKY, while calcitonin generelated peptide (CGRP) induced a profound relaxation response. Relaxation response to CGRP was significantly greater in SHRSP than in WKY. Atrial, brain, and C-type natriur etic peptides (ANP, BNP, CNP), vasoactive intestinal polypeptide (VIP), and peptide histidine isoleucine (PHI) all caused relaxation responses, with a greater extent of relaxation to ANP, BNP, and VIP and a less extent to CNP and PHI. However, there were no significant differences in these relaxation responses between SHRSP and WKY. The current results revealed the character of heterogeneity of rat intrarenal arteries in response to vasoconstrictor and vasodilator peptides, and showed an enhanced reactivity to ET-1 and to CGRP in SHRSP.
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