• Title/Summary/Keyword: size of the myocytes

Search Result 3, Processing Time 0.018 seconds

Spatiotemporal characteristics of atrial $Ca^{2+}$ sparks: evidence from two-dimensional rapid confocal imaging

  • Woo, Sun-Hee;Lars Cleemann;Martin Morad
    • Proceedings of the Korean Biophysical Society Conference
    • /
    • 2003.06a
    • /
    • pp.25-25
    • /
    • 2003
  • Atrial myocytes have two functionally separate $Ca^{2+}$ release sites: those in peripheral sarcoplasmic reticulum (SR) adjacent to the $Ca^{2+}$ channels of surface membrane and those in central SR not associated with $Ca^{2+}$ channels. Study on the spatio-temporal properties of focal $Ca^{2+}$ releases (“sparks”) occurring spontaneously in central and peripheral sites of voltage-clamped rat atrial myocytes, using rapid two-dimensional (2-D) confocal $Ca^{2+}$ imaging revealed that peripheral and central sparks were similar in size and release time (~300,000 $Ca^{2+}$ ions for=12 ms), but significantly larger and longer than ventricular sparks. Both sites were resistant to Cd$^{2+}$ and inhibited by ryanodine. Peripheral sparks were brighter and flattened against surface membrane, had ~5-fold higher frequency, ~2 times faster diffusion coefficient, and dissipated abruptly. Central sparks, in contrast, occurred less frequently, were elongated along the cellular longitudinal axis, and dissipated slowly. Compound sparks (composed of 2-5 unitary focal releases) aligned longitudinally, occurred more frequently at the center.at the center.

  • PDF

Histological Effects of Fishery By-product Fermented Fishmeal on the Liver and Muscle of the Olive Flounder Paralichthys olivaceus (수산부산물 발효어분이 넙치(Paralichthys olivaceu)의 간 및 근육에 미치는 영향에 관한 조직학적 연구)

  • Lee, Bo-Ram;Kim, Ji-Hye
    • Journal of Life Science
    • /
    • v.29 no.11
    • /
    • pp.1235-1240
    • /
    • 2019
  • The aim of this study was to clarify histologically the effects of fermented fishmeal on the growth rate of fish. For this purpose, olive flounders were fed on fermented fishmeal at the substitution ratios of 0, 25, 50, 75, and 100%, and the effects on the liver and muscle were examined by microscopy. The olive flounder fed on fermented fishmeal at the 25% substitution ratio had the best hepatic condition, as indicated by the highest hepatosomatic index and the lowest fatty liver level, when compared with fish fed the other substitution ratios. The olive flounder fed on fermented fishmeal at the 25% substitution ratio had good motility, based on the presence of wide myocytes. The high growth rate in the olive flounder fed on fermented fishmeal at the 25% substitution ratio therefore seemed to be related to the health status of the liver and muscles. Higher amounts of the fermented fishmeal (75% and 100% substitution ratios) suppressed the growth rate due to adverse effects on hepatic function and motility of the olive flounder.

Histological Changes in Biceps Muscle after Tenotomizing the Biceps Long Head in a Rat Model

  • Song, Ha-Jung;Heu, Jun-Young;Song, Hyun Seok
    • Clinics in Shoulder and Elbow
    • /
    • v.21 no.2
    • /
    • pp.87-94
    • /
    • 2018
  • Background: Popeye deformity is common after rupture of the biceps muscle's long head tendon. Herein, we report on histological changes in biceps brachii muscles following tenotomy of the long head biceps tendon. Methods: Twelve Sprague-Dawley rats (12-week-old) underwent tenotomy of the long head biceps tendon in the right shoulder. At postoperative weeks 4, 7, and 10, the operative shoulders were removed by detaching the biceps brachii muscle from the glenoid scapula and humerus; the opposite shoulders were removed as controls. H&E staining was performed to elucidate histological changes in myocytes. Oil-red O staining was performed to determine fatty infiltration. Myostatin antibody immunohistochemistry staining was performed as myostatin is expressed by skeletal muscle cells during myogenesis. Results: H&E staining results revealed no changes in muscle cell nuclei. There were no adipocytes detected. Compared with that of the control biceps, the cross-sectional area of the long head biceps was significantly smaller (p=0.00). Statistical changes in the total extent of the 100 muscle cells were significant (p=0.00). Oil-red O staining revealed no fatty infiltration. Myostatin antibody immunohistochemical staining revealed no significant difference between the two sides. Conclusions: Muscular changes after tenotomy of the long head biceps included a decrease in the size of the individual muscle cells and in relative muscle mass. There were no changes observed in muscle cell nuclei and no fatty infiltration. Moreover, there were no changes detected by myostatin antibody immunohistochemistry assay.