Elevated levels of the histidine catabolito formiminoglutamic acid were excreted into the urine of rats that were given both 0.01% diethylnitrosamine in their drinking water for 1 to 5 weeks and an injection of a loading dose of histidine. Similar histidine loading of control rats that received no carcinogen did not produce an elevation in urinary formiminoglutamic acid excretion. The elevation...

Elevated levels of the histidine catabolito formiminoglutamic acid were excreted into the urine of rats that were given both 0.01% diethylnitrosamine in their drinking water for 1 to 5 weeks and an injection of a loading dose of histidine. Similar histidine loading of control rats that received no carcinogen did not produce an elevation in urinary formiminoglutamic acid excretion. The elevation...

Despite being of high biotechnological relevance, many aspects of organic acid excretion in filamentous fungi like the influence of ambient pH are still insufficiently understood. While the excretion of an individual organic acid may peak at a certain pH value, the few available studies investigating a broader range of organic acids indicate that total organic acid excretion rises with increasi...

In 1946, Rosen e2 al. (1) showed that administration of tryptophan to rats resulted in an additional excretion of nicotinic acid and Nl-methylnicotinamide (Nl-Me). Singal et al. (2) found, in addition to these, increased excretion of another metabolite which could be converted to nicotinic acid by autoclaving in 1 N sulfuric acid solution. Henderson isolated this metabolite from the urine of ra...

The effect of a dose of alcohol on the kinetics of mandelic acid excretion in four volunteers exposed to 220 mg/m3 styrene has been investigated under controlled exposure chamber conditions. Ethanol inhibited the excretion of mandelic acid, so that the peak excretion was delayed from the end of the exposure period until three hours afterwards. One hour after administration of ethanol blood mand...

Although adrenalectomy is usually associated with an impairment of ammonium and/or titratable acid excretion by the kidney, it is uncertain whether rates of renal net acid excretion are also reduced. Further, it is unclear whether the absence of the adrenal gland itself or other factors of adrenal insufficiency mediate such changes in renal acidification parameters. For example, dramatic increa...

The addition of corn products to a synthetic low protein diet very low in nicotinic acid has been reported by Krehl and coworkers (1,2) to depress growth in rats. This growth retardation could be prevented by tryptophan as well as by nicotinic acid. These findings have been confirmed in this laboratory by the paired feeding technique (3) and by other investigators (4, 5). The interchangeability...

African lungfish Protopterus annectens utilized both respiratory and metabolic compensation to restore arterial pH to control levels following the imposition of a metabolic acidosis or alkalosis. Acid infusion (3 mmol kg(-1) NH(4)Cl) to lower arterial pH by 0.24 units increased both pulmonary (by 1.8-fold) and branchial (by 1.7-fold) ventilation frequencies significantly, contributing to 4.8-fo...

We investigated the role of organic acids in conferring Al tolerance in near-isogenic wheat (Triticum aestivum L.) lines differing in Al tolerance at the Al tolerance locus (Alt1). Addition of Al to nutrient solutions stimulated excretion of malic and succinic acids from roots of wheat seedlings, and Al-tolerant genotypes excreted 5- to 10-fold more malic acid than Al-sensitive genotypes. Malic...

Demain, A. L. (Merck & Co., Inc., Rahway, N.J.), R. W. Burg, and D. Hendlin. Excretion and degradation of ribonucleic acid by Bacillus subtilis. J. Bacteriol. 89:640-646. 1965.-Bacillus subtilis MB-1480 was found to produce several 5'-ribonucleotides in the extracellular medium, in addition to the previously found 5'-guanosine monophosphate and guanosine diphosphate. The nucleotides accumulated...