Department of Zoology, University of British Columbia, 6270 University Boulevard, V6T 2A9, Vancouver, B.C., Canada.
Fish Physiol Biochem. 1989 Jan;6(1):1-9. doi: 10.1007/BF01875599.
Starry flounder (Platichthys stellatus) were cannulated and a bolus of 9 μCi(14)C-creatine in saline was injected into the caudal vein. The fish were sacrificed at intervals ranging from 1h to 36d after label injection. Creatine pool size (PCr+Cr) and creatinine (Crn) content in blood, muscle, gills and liver were analyzed and specific activities (SA) determined.Mean concentrations of PCr+Cr/Crn in PCA-extracts of muscle, gills, liver and blood of experimental fish (at rest) were 38.1/2.40, 4.1/0.25, 5.6/0.45 and 0.3/n.d. μmol.g(-1) respectively.Within 10 min, plasma SA had decreased by approximately 90%. In white muscle, the rate of(14)C-Cr appearance as well as label disappearance was slow compared to gills and liver. In fish examined 36d postinjection, mean SA in muscle had decreased to 23% of maximum SA which occurred 24h after injection.(14)C-Cr was incorporated into the liver tissue at a very high rate, SA being two orders of magnitude higher in liver than in white muscle. Over the first 6d, retention of label was observed in liver; after 36d only 3% of the original label was detected.Creatine pool size (PCr+Cr) in white muscle decreased with food deprivation. In flounder sacrificed after 36d, PCr+Cr was only 52% that of fed control fish, suggesting that creatine or precursors for its biosynthesis are supplied with the diet.
星鲽（Platichthys stellatus）被插管，然后将 9μCi（14）C-肌酸盐水溶液弹丸注入尾静脉。在标记注射后 1h 至 36d 之间的不同时间点处死鱼。分析血液、肌肉、鳃和肝脏中的肌酸池大小（PCr+Cr）和肌酸（Crn）含量，并测定比活度（SA）。实验鱼（休息时）肌肉、鳃、肝脏和血液 PCA 提取物中 PCr+Cr/Crn 的平均浓度分别为 38.1/2.40、4.1/0.25、5.6/0.45 和 0.3/n.d.μmol.g(-1)。在 10min 内，血浆 SA 减少了约 90%。在白肌中，14C-Cr 的出现率和标记消失率比鳃和肝脏慢。在注射后 36d 检查的鱼中，肌肉的平均 SA 已降低至最大 SA 的 23%，最大 SA 出现在注射后 24h。14C-Cr 以非常高的速率掺入肝脏组织中，肝脏中的 SA 比白肌高两个数量级。在最初的 6d 内，观察到肝脏中保留了标记；36d 后，仅检测到原始标记的 3%。白肌中的肌酸池大小（PCr+Cr）随禁食而减少。在 36d 后处死的星鲽中，PCr+Cr 仅为摄食对照鱼的 52%，表明肌酸或其生物合成的前体是通过饮食提供的。
