Metabolic control reactions of the intact urinary bladder of the toad

✍ Scribed by Mitzy Canessa-Fischer; Robert P. Davis

• Publisher: John Wiley and Sons
• Year: 1966
• Tongue: English
• Weight: 794 KB
• Volume: 67
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1040670215

✦ Synopsis

Metabolic control reactions have been studied in the intact toad bladder by means of fluorescence spectrophotometric measurement of reduced pyridine nucleotide and by measurement of respiration with the platinum electrode. Substrates such as pyruvate and succinate lead to prompt increases in reduction level of pyridine nucleotide with only slight acceleration of respiration. Major metabolic control is exerted by ADP, which depletes the intact bladder of reduced pyridine nucleotide and accelerates respiration. Respiratory control ratios, as for isolated mitochondria, depend upon the substrate being metabolized. A significant fraction of added ADP appears to gain entry into the intact toad bladder and is converted to ATP, Anaerobiosis and amobarbital lead to increased levels of reduction of pyridine nucleotide. The spectroscopic and metabolic properties of the reduced pyridine nucleotide being studied identify it with that fraction of DPNH which is bound at one of the energy conservation sites linking phosphorylation reactions with electron transfer.