In ruminants excess dietary Nitrogen (N) is excreted as urea mainly through urine. Urea, the major form of urinary N is rapidly converted to ammonia after excretion. Ammonia is an important environmental pollutant that impacts the quality of human and animal life .The NRC (2001) considered ammonia emissions from concentrated animal feeding operations (CAFO) as a major air quality concern. Ammon...

Studies previously reported (l-3)) involving the constant intravenous infusion of a number of amino acids, singly and in combination, have permitted the authors to obtain data concerning a number of physiological and biochemical phenomena associated with amino acid metabolism. The present report deals with the effect of amino acid infusion upon the renal excretion of ammonia. In this phase of m...

African lungfishes are ammonotelic in water. They can aestivate for long periods on land during drought. During aestivation, the gills are covered with dried mucus and ammonia excretion ceases. In fishes, ammonia excretion through the gills involves Rhesus glycoproteins (RhGP/Rhgp). This study aimed to obtain the complete cDNA coding sequences of rhgp from the gills of Protopterus annectens, an...

Hypokalemia is a common electrolyte disorder that increases renal ammonia metabolism and can cause the development of an acid-base disorder, metabolic alkalosis. The ammonia transporter family members, Rh B glycoprotein (Rhbg) and Rh C glycoprotein (Rhcg), are expressed in the distal nephron and collecting duct and mediate critical roles in acid-base homeostasis by facilitating ammonia secretio...

Ammonia (NH3) emissions originate predominantly from manure. In outdoor pig production, excretory behaviour creates nitrogen (N) point loads. This study examined ammonia losses from pigs on grassland at two farms by calculating N field balances per pen and sub-areas preferred (P) and not preferred (NP) for excretion. Spatial variation in ammonia losses was measured with an equilibrium concentra...

The ornithine­urea cycle (OUC) is present in elasmobranch fish and many terrestrial vertebrates. Recently, a functional OUC has been reported in a few teleost species, suggesting that all teleost fish have the genes for the OUC, but expression is relatively rare. We investigated the possibility that the OUC is expressed during early development in trout as a mechanism for detoxifying ammoni...

We obtained a full cDNA coding sequence of aquaporin 1aa (aqp1aa) from the gills of the freshwater climbing perch, Anabas testudineus, which had the highest expression in the gills and skin, suggesting an important role of Aqp1aa in these organs. Since seawater acclimation had no significant effects on the branchial and intestinal aqp1aa mRNA expression, and since the mRNA expression of aqp1aa ...

Goldfish acclimated to cold water (e.g. 7°C) experience a marked reduction in functional lamellar surface area owing to the proliferation of an interlamellar cell mass (ILCM), a phenomenon termed gill remodelling. The goal of the present study was to assess the consequences of the reduced functional surface area on the capacity of goldfish to excrete ammonia. Despite the expected impact of ambi...