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991.
T Tameyasu 《Experientia》1990,46(7):677-679
Changes in the profile of equatorial intensities of X-ray diffraction from an intact, anterior byssal retractor muscle (ABRM) of Mytilus were examined at rest, during contracture brought about by acetylcholine (ACh) and a subsequent rigor-like contraction caused by raising the tonicity of the external solution, and after returning the tonicity to normal. The results suggest that the cross-bridges formed between thick and thin actin filaments during the ACh-contracture were maintained in the hypertonic solution and broken on decreasing the tonicity before the recovery of spacing of the actin filament lattice. A similar rigor-like contraction was induced in glycerinated ABRM by increasing salt concentration during active contraction. The rigor-like force declined rapidly when Ca++ concentration decreased. The results suggest that the detachment of the cross-bridge from the actin filament is regulated by Ca++ at high ionic strength in the ABRM. 相似文献
992.
Binding of myosin I to membrane lipids 总被引:39,自引:0,他引:39
The single-headed myosins called myosin-I were first isolated from the protozoan Acanthamoeba and subsequently identified in other cells. We previously reported evidence that myosin-I is responsible for the movement of membranes, extracted from Acanthamoeba, along actin filaments in vitro. Here we show for the first time that myosin-I can bind directly to NaOH-extracted membranes isolated from Acanthamoeba and to vesicles of pure lipids with an affinity sufficient for extensive binding in the cell. Membrane-bound myosin-I may provide a mechanism for many cellular movements previously thought to involve filamentous myosin-II. 相似文献
993.
Under in vitro conditions the time-dependent inactivation process of LH/HCG receptors is nearly identical in ovarian and testicular homogenates but different in gonadal membrane preparations. In the ovarian membranes the loss of binding sites during the first preincubation time is faster than in testicular membranes, especially in membranes of luteinized rat ovaries. Compared with the homogenates, however, the receptor-inactivation in the membranes is generally delayed. The inhibitory effect of metabolic agents on receptor inactivation indicates that membrane-associated actions are involved in this process. 相似文献
994.
Enumeration of different types of spermatogonia, following a single i.p. administration of different doses of ethyl methanesulfonate in mice, showed a survival of A1-A4 and in spermatogonia is markedly reduced due to cell killing while the remaining types of spermatogonia were affected marginally. The cell killing effect was dose-dependent, and replenishment of these cells was observed by the end of one cycle of the seminiferous epithelium comprising of 8.5 days. 相似文献
995.
A. W. T. Konings 《Cellular and molecular life sciences : CMLS》1971,27(3):253-254
Résumé Les expériences présentées montrent que dans les noyaux isolés du thymus de rat l'inhibition de glycéraldehyde-phosphate déhydrogénase stimule la production de14CO2 de (6-14C) glucose. Un méchanisme capable d'expliquer cet effet est proposé et discuté. 相似文献
996.
T W Stone 《Experientia》1973,29(6):666-667
997.
998.
M. Jakóbisiak M. Kamiński A. E. Kossakowska T. Rymaszewska-Kossakowska 《Cellular and molecular life sciences : CMLS》1973,29(3):335-336
Zusammenfassung Nachweis eines Hemmeffektes immunosupressiver Mittel (Cortison, Cyclophosphamide und Immuran) bei Mäusen nach UV-Bestrahlung auf die hämopoetische Regeneration (Milzkolonien und Knochenmarkzellen). 相似文献
999.
1000.