Biomedical subjects

A D Muir

Publications and source records attributed to A D Muir.

27 records · Page 2Linked to original sources

PubMed1984

Absorption of 3-nitropropanol and 3-nitropropionic acid from the digestive system of sheep.

When 3-nitropropanol (NPOH) was injected into the rumen (30 mg/kg), abomasum (10 mg/kg) or small intestine (10 mg/kg) of sheep, it was rapidly absorbed and converted to 3-nitropropionic acid (NPA). The reticulo-rumen was the major site of absorption for the miserotoxin aglycone but the abomasum and the small intestine also had the capacity to absorb NPOH. When NPA was injected into different regions of the alimentary tract, the reticulo-rumen was also the major site of absorption. Absorption of NPA or NPOH from the small intestine was much more rapid than from the abomasum. Plasma levels of NPA and inorganic nitrite were higher after dosing with NPOH than with NPA indicating a more rapid rate of uptake of the aglycone.

1-Propanol↗

PubMed1984

Absorption of 3-nitropropanol (miserotoxin aglycone) from the compound stomach of cattle.

Miserotoxin, the toxic component of certain Astragalus spp. (Leguminosae), was rapidly hydrolyzed to 3-nitropropanol (NPOH) in the rumen of cattle dosed with timber milkvetch (A. miser var. serotinus). The aglycone showed a rapid rate of disappearance from the rumen with an average half-life of 1.24 h. In contrast to the passage of Co-EDTA, which showed an exponential rate of increase in the abomasum, NPOH was not detected in abomasal fluid collected from dosed cattle. Rapid absorption of NPOH from the rumen was shown by plasma levels of 3-nitropropionic acid (NPA) and inorganic nitrite, but conversion of NPOH to NPA was not observed to any significant extent in the rumen.

1-Propanol↗

PubMed1984

Quantitative determination of 3-nitropropionic acid and 3-nitropropanol in plasma by HPLC.

The separation and determination of 3-nitropropanol (NPOH) and 3-nitropropionic acid (NPA) by reverse-phase high-pressure liquid chromatography (HPLC) is described. The system consists of a Micropak MCH-5 column eluted isocratically with 0.15% orthophosphoric acid (pH 2.0). This technique permits the simultaneous determination of NPA and NPOH in bovine and ovine plasma.

1-Propanol↗

PubMed1984

Conversion of 3-nitropropanol (miserotoxin aglycone) to 3-nitropropionic acid in cattle and sheep.

The metabolism of intravenously administered 3-nitropropanol (miserotoxin aglycone) was examined in cattle and sheep using high-pressure liquid chromatography (HPLC) to determine nitrocompounds in plasma. 3-Nitropropanol (NPOH) showed a rapid rate of decay and simultaneously, 3-nitropropionic acid (NPA) was detected at comparable levels in plasma. In animals dosed with NPOH, the observed NPA decayed at a slower rate than NPOH. Nitrite levels in plasma were more closely related to NPA than to NPOH. Therefore, metabolism of NPOH is linked to NPA and this could provide a common basis for the toxicity of these compounds in cattle and sheep.

1-Propanol↗

PubMed1982