Intracellular calcium levels in canine basilar artery smooth muscle following experimental subarachnoid hemorrhage: an electron microscopic cytochemical study

1991 ◽  
Vol 81 (6) ◽  
pp. 664-669 ◽  
Author(s):  
K. Kohno ◽  
S. Sakaki ◽  
S. Ohue ◽  
Y. Kumon ◽  
K. Matsuoka
Keyword(s):  
Smooth Muscle ◽  
Subarachnoid Hemorrhage ◽  
Intracellular Calcium ◽  
Basilar Artery ◽  
Electron Microscopic ◽  
Cytochemical Study ◽  
Experimental Subarachnoid Hemorrhage ◽  
Canine Basilar Artery

scholarly journals Impaired Calcium Regulation of Smooth Muscle during Chronic Vasospasm following Subarachnoid Hemorrhage

1996 ◽  
Vol 16 (2) ◽  
pp. 334-341 ◽  
Author(s):  
Phyo Kim ◽  
Yuhei Yoshimoto ◽  
Masamitsu Iino ◽  
Sasaki Tomio ◽  
Takaaki Kirino ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Subarachnoid Hemorrhage ◽  
Intracellular Calcium ◽  
Basilar Artery ◽  
Calcium Concentration ◽  
Calcium Regulation ◽  
Control Group ◽  
Intracellular Calcium Level ◽  
Canine Basilar Artery ◽  
Chronic Vasospasm

The intracellular calcium level was determined in the canine basilar artery to investigate whether Ca2+regulation of its smooth muscle is altered during chronic vasospasm following subarachnoid hemorrhage. A double-hemorrhage model was used. The occurrence of vasospasm was confirmed angiographically 7 days after initial hemorrhage. The intracellular calcium concentration ([Ca2+]i) of smooth muscle was measured using Fura-2. Fluorescence to excitation at 340 and 356 nm was monitored and the ratio R340/356 was used as the indicator of [Ca2+]i. When the extracellular calcium concentration ([Ca2+]e) was increased from pCa 8 to 2, [Ca2+]i also increased. In the spastic arteries, the [Ca2+]e − [Ca2+]i curve was elevated as compared with the normal arteries. Treatment with ionomycin elevated the curve in the normal group, but it had little effect in the spastic arteries. Values of [Ca2+]i, calculated in multiples of Kd, were greater in the spastic arteries. Diltiazem (10;−5 mol/L) partially suppressed the augmented [Ca2+]i signal in the spastic arteries, whereas it did not affect the curve in the control group. These results indicate that calcium regulation of smooth muscle is impaired after subarachnoid hemorrhage, which may contribute to the pathogenesis of chronic vasospasm.

scholarly journals Inducible Cyclooxygenase Expression in Canine Basilar Artery After Experimental Subarachnoid Hemorrhage

Stroke ◽  
1998 ◽  
Vol 29 (6) ◽  
pp. 1219-1222 ◽  
Author(s):  
Koji Osuka ◽  
Yoshio Suzuki ◽  
Yasuo Watanabe ◽  
Masakazu Takayasu ◽  
Jun Yoshida
Keyword(s):  
Subarachnoid Hemorrhage ◽  
Basilar Artery ◽  
Experimental Subarachnoid Hemorrhage ◽  
Canine Basilar Artery

scholarly journals Protein Synthesis and Immunoreactivities of Contraction-Related Proteins in Smooth Muscle Cells of Canine Basilar Artery after Experimental Subarachnoid Hemorrhage

1996 ◽  
Vol 16 (6) ◽  
pp. 1335-1344 ◽  
Author(s):  
Yoshihisa Oka ◽  
Shinsuke Ohta ◽  
Hirooki Todo ◽  
Kanehisa Kohno ◽  
Yoshiaki Kumon ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Smooth Muscle ◽  
Subarachnoid Hemorrhage ◽  
Smooth Muscle Cells ◽  
Basilar Artery ◽  
Muscle Cells ◽  
Relative Reduction ◽  
Aggregation Rate ◽  
Basilar Arteries ◽  
Experimental Subarachnoid Hemorrhage

We examined time-dependent changes in protein synthesis and in the immunoreactivities of representative contraction-related structural proteins in smooth muscle cells of canine basilar arteries after experimental subarachnoid hemorrhage (SAH). Protein synthesis was assessed by the percentage of polyribosome-forming ribosomes to total ribosomes (aggregation rate), a morphological index of the activity of protein synthesis. The aggregation rates in prostaglandin F2α- (PGF2α) and 12- O-tetradecanoyl-phorbol-13-acetate (TPA)-induced contracted basilar arteries were 70.0 ± 7.0% and 71.4 ± 8.7%, respectively, quite similar to the value in normal basilar artery (73.0 ± 8.0%). In the single-SAH group with little delayed histological changes in the basilar arteries, the aggregation rate was significantly decreased to 30.5 ± 6.4% by 24 h after the SAH, and recovered to 52.3 ± 9.0% and 70.2 ± 7.6% at 7 and 14 days postSAH, respectively, when the vasospasm was moderately and completely ameliorated. In contrast, in the double-SAH group in which the basilar arteries developed delayed smooth muscle cell death and long-lasting arterial contraction, a significant decrease in the aggregation rate (25.0 ± 5.0% on day 4) persisted for 14 days. The in vitro incorporation of [3H]-leucine in the basilar arterial cells was also significantly suppressed 4 and 7 days after the initial SAH (1.2 ± 0.4 and 1.4 ± 0.3 × 103 dpm/mg protein) in the double-SAH group, as opposed to no significant decrease in the basilar artery at 7 days postSAH in the single-SAH group (1.9 ± 0.6 × 103 dpm/mg protein). The immunoreactivity of α-smooth muscle actin, a contractile protein, demonstrated by immunohistochemistry and immunoblots, was not altered for up to 14 days even in the double-SAH group, but that of calponin and of h-caldesmon, contraction-inhibiting proteins, was markedly reduced 4–14 days after the initial SAH. Persistent impairment of protein synthesis and relative reduction of immunoreactivities of the contraction-inhibiting proteins were observed in arteries with severe vasospasm and loss of smooth muscle cells, as noted in the double-SAH subjects. These abnormalities may cooperate to cause cerebral arterial narrowing accompanied by degeneration of smooth muscle cells after SAH.

Changes in Ca++-ATPase activity in smooth-muscle cell membranes of the canine basilar artery with experimental subarachnoid hemorrhage

1994 ◽  
Vol 80 (2) ◽  
pp. 269-275 ◽  
Author(s):  
Jinze Wang ◽  
Shinsuke Ohta ◽  
Saburo Sakaki ◽  
Nobukazu Araki ◽  
Seiji Matsuda ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Plasma Membrane ◽  
Subarachnoid Hemorrhage ◽  
Atpase Activity ◽  
Smooth Muscle Cells ◽  
Basilar Artery ◽  
Muscle Cells ◽  
Arterial Blood ◽  
Basilar Arteries ◽  
Experimental Subarachnoid Hemorrhage

✓ Changes in Ca++-adenosine triphosphatase (ATPase) activity in the plasma membrane of smooth-muscle cells in the basilar arteries of dogs with experimental subarachnoid hemorrhage (SAH) were examined. The study methods included electron microscopic histochemistry and bioassay of the enzyme that exports cytoplasmic Ca++ to extracellular spaces. The Ca++-ATPase activity in the basilar artery increased significantly in response to the application of vasoconstrictive agents (prostaglandin F2α and a phorbol ester), but decreased significantly 24 hours after experimental SAH, inversely with basilar artery contraction. Dogs that had undergone two arterial blood injections (double SAH) exhibited a further decrease in Ca++-ATPase activity as well as persistent contraction of the basilar artery for a longer period (at least 7 days) than was seen in animals with a single arterial blood injection. Bioassay of the enzyme also demonstrated a decrease in vascular Ca++-ATPase activity in dogs subjected to double SAH. These findings suggest that the early occurrence of and long-lasting decrease in Ca++-ATPase activity in dogs with experimental SAH induces a persistent disturbance of Ca++ homeostasis and indicates that damage to the plasma membrane in the cerebral arterial smooth-muscle cells proceeds to myonecrosis after SAH.

scholarly journals Activation of Protein Kinases in Canine Basilar Artery in Vasospasm

1999 ◽  
Vol 19 (1) ◽  
pp. 44-52 ◽  
Author(s):  
Hirokazu Fujikawa ◽  
Eiichi Tani ◽  
Ikuya Yamaura ◽  
Isao Ozaki ◽  
Katsuya Miyaji ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Protein Kinase ◽  
Tyrosine Kinase ◽  
Basilar Artery ◽  
Molecular Mechanisms ◽  
Kinase Inhibitor ◽  
Polyacrylamide Gel Electrophoresis ◽  
Intracellular Ca ◽  
Canine Basilar Artery ◽  
Kinase Pathway

Subarachnoid hemorrhage (SAH) often leads to a long-term narrowing of cerebral artery called vasospasm. To understand the molecular mechanisms in vasospasm, signal transduction of tyrosine kinase pathway and phosphorylation of myosin light chain (MLC) and calponin (CaP) in the basilar artery were studied. Vasospasm was produced in the canine basilar artery by a two-hemorrhage method, and vasocontraction was induced by a local application of KCl or serotonin to the basilar artery after a transclival exposure. Intracellular substrates of tyrosine kinase pathway, including Shc, Raf1, and extracellular-regulated kinases in the basilar artery, were activated after SAH, and the activation of Shc suggests stimulation of signal transductions from tyrosine kinase receptors, G-coupled receptors, or both. The activation of tyrosine kinase pathway in vasospasm also was supported by dose-dependent dilation of the spastic basilar artery on days 0 and 7 by topical application of genistein, a tyrosine kinase inhibitor, and associated marked inhibition of tyrosine phosphorylation of intracellular substrates, including Shc. In addition, the generation of protein kinase M, catalytic fragment of protein kinase Cα (PKCα), in vasospasm on days 0 and 7 was inhibited in response to genistein, indicating an inactivation of μ-calpain. It is suggested, therefore, that the reversal of vasospasm by genistein is closely associated with the restoration of intracellular Ca2+ levels. However, the increased activities of Raf1 and extracellular-regulated kinases in vasospasm were declined on day 7 compared with those on day 0 or 2, suggesting that the activation of tyrosine kinase pathway is more closely associated with the early stage of vasospasm than with the late stage of vasospasm. The analysis by pyrophosphate polyacrylamide gel electrophoresis (PPi-PAGE) demonstrated three MLC bands in vasospasm on days 2 and 7, as well as in KCl- and serotonin-induced vasocontraction. Since PPi-PAGE resolves smooth muscle MLC into three bands in the MLC kinase (MLCK)-mediated phosphorylation and into a single band in the PKC-mediated phosphorylation based on the phosphorylation state, the current results suggest that MLC in vasospasm is phosphorylated by MLCK but not by PKC. In basilar artery, CaP was significantly down-regulated, and in addition, significantly phosphorylated on serine and threonine residues only in vasospasm on days 2 and 7. Although the significance of CaP phosphorylations in vivo still is controversial, CaP down-regulation and phosphorylation may attenuate the inhibition of Mg2+-ATPase activity by CaP and induce a potential enhancement of smooth muscle contractility in delayed vasospasm. Since CaP is phosphorylated vivo by PKC, activated PKC in vasospasm may phosphorylate CaP. Thus, SAH stimulates tyrosine kinase pathway to increase intracellular Ca2+ and activate PKC, and the former activates MLCK to phosphorylate MLC, whereas the latter phosphorylates CaP but not MLC.

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