ULTRASTRUCTURAL STUDIES OF SITE OF ACTION OF RYANODINE ON HEART-MUSCLE

作     者：PENEFSKY, ZJ 

作者机构：CITY UNIV NEW YORKMT SINAI SCH MEDDEPT PHYSIOL10 E 102ND STNEW YORKNY 10029 

出 版 物：《PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY》 (Pflugers Arch.)

年 卷 期：1974年第347卷第3期

页      面：185-198页

核心收录：

学科分类：0710[理学-生物学] 07[理学] 071003[理学-生理学] 

主　　题：Excitation-Contraction Coupling Ryanodine Structure-Function Relationships Transverse Tubules 

摘      要：A correlation has been identified between the sensitivity of cardiac muscle to ryanodine and the presence in the muscle of a transverse tubular system. Thus ryanodine failed to inhibit cardiac contraction in tissues which lack a transverse tubular system such as mammalian fetal heart and batracian heart. In the mammalian newborn the inhibition of contractile tension by ryanodine increased during that period of growth when evidence for a developing T system was apparent in electron micrographs. Concentrations of ryanodine sufficient to inhibit contraction of adult mammalian heart muscle were observed to alter the ultrastructure of the tissue. Ryanodine treatment brought about a separation of the sarcolemma at the level of the Z lines and appeared to cause wrinkling and an apparent evagination of the sarcolemma at sarcomere lengths of 2 μ or less. It is suggested that ryanodine inhibits contraction of adult mammalian heart muscle by dissociating the T tubules from the sarcoplasmic reticulum system and thus uncoupling excitation from contraction.