Ishii N, Mitsumori F, Takahashi K
Department of Sports Sciences, College of Arts and Sciences, University of Tokyo, Japan.
J Muscle Res Cell Motil. 1991 Jun;12(3):242-6. doi: 10.1007/BF01745113.
The sarcoplasmic concentrations of phosphorus metabolites and pH (pHin) were measured in the anterior byssus retractor muscle (ABRM) of Mytilus edulis by 31P nuclear magnetic resonance spectroscopy. During an active contraction induced by 10(-3) acetylcholine, the concentration of arginine phosphate ([Arg-P]in) decreased from the resting value of 7.47 +/- 0.26 (mean +/- SE, n = 8) to 6.67 +/- 0.29 (n = 6) mumol g-1, and that of inorganic phosphate (Pi) consistently increased from 0.84 +/- 0.06 (n = 7) to 1.61 +/- 0.12 (n = 5) mumol g-1. In the 'catch' state following the active contraction, these concentrations were close to their resting levels, indicating that the catch is an inactive state. 5-hydroxytryptamine caused a rapid relaxation of the catch, which was associated with a slight decrease in [Arg-P]in and an increase in pHin by ca 0.2 units. The sarcoplasmic concentration of ATP (mean, 1.6 mumol g-1) did not change throughout the contraction-relaxation cycle.
采用³¹P核磁共振波谱法测定了紫贻贝前足丝收缩肌(ABRM)中磷代谢物的肌浆浓度和pH值(pHin)。在由10⁻³乙酰胆碱诱导的主动收缩过程中,磷酸精氨酸([Arg-P]in)的浓度从静息值7.47±0.26(平均值±标准误,n = 8)降至6.67±0.29(n = 6)μmol g⁻¹,无机磷酸盐(Pi)的浓度则持续从0.84±0.06(n = 7)升至1.61±0.12(n = 5)μmol g⁻¹。在主动收缩后的“强直收缩”状态下,这些浓度接近其静息水平,表明强直收缩是一种非活动状态。5-羟色胺导致强直收缩迅速松弛,这与[Arg-P]in略有下降以及pHin升高约0.2个单位有关。在整个收缩-松弛周期中,肌浆ATP浓度(平均值为1.6μmol g⁻¹)没有变化。