Boulanger Y, Legault P, Tejedor A, Vinay P, Theriault Y
Institut de génie biomédical Université de Montréal, (Québec), Canada.
Can J Physiol Pharmacol. 1988 Oct;66(10):1282-90. doi: 10.1139/y88-210.
Papillary collecting duct tubules were prepared in gram quantities from the papillae of dog and pig kidneys. Measurements of substrate and oxygen utilizations by these tubules under both aerobic and anaerobic conditions showed the potential for both glycolysis and oxidative phosphorylation. Oxygen is not necessary to maintain a normal adenosine 5'-triphosphate concentration, but oxidative phosphorylation contributes to more than 65% of the metabolism under aerobic conditions in the two species. Both phosphorus-31 and proton nuclear magnetic resonance spectra recorded from extracts of dog cortex, red medulla, and papilla showed a clear gradient from cortex to papilla for osmolytes, such as glycerophosphorylcholine, sorbitol, inositol, betaine, and sugar phosphates. Other molecules identified in the spectra included glucose, sorbitol, mannitol, lactate, glutamine, alanine, threonine, and adenosine 5'-triphosphate. Conventional biochemical measurements supported these findings. An increase in osmolality from 300 to 600 mosmol/kg H2O for 120 min did not increase the glycerophosphorylcholine and sorbitol concentrations of dog papillary collecting ducts in vitro, but a small effect of a 24-h dehydration was detected in vivo.
从狗和猪的肾乳头中制备了克级量的乳头集合管。在有氧和无氧条件下对这些小管的底物利用和氧利用进行的测量表明，其具有糖酵解和氧化磷酸化的潜力。维持正常的5'-三磷酸腺苷浓度并不需要氧气，但在这两个物种的有氧条件下，氧化磷酸化对代谢的贡献超过65%。从狗的皮质、红髓和乳头提取物中记录的磷-31和质子核磁共振谱显示，渗透压溶质（如甘油磷酸胆碱、山梨醇、肌醇、甜菜碱和糖磷酸盐）从皮质到乳头呈现明显的梯度。光谱中鉴定出的其他分子包括葡萄糖、山梨醇、甘露醇、乳酸、谷氨酰胺、丙氨酸、苏氨酸和5'-三磷酸腺苷。传统的生化测量支持了这些发现。在体外，将渗透压从300 mosmol/kg H2O增加到600 mosmol/kg H2O持续120分钟，并未增加狗乳头集合管中甘油磷酸胆碱和山梨醇的浓度，但在体内检测到24小时脱水有轻微影响。
