The metabolism and urinary excretion of orotic acid in hyperargininaemic sheep.

The synthesis, blood plasma turnover and urinary excretion of the orotic acid in normo- and hyperargininaemic sheep was investigated. The whole-body orotate formation was evaluated indirectly by the measurement of urinary orotate excretion after blockage of pyrimidine pathway with 6-azauridine (4 hour i.v.

Urinary excretion of purines in sheep with experimental orotic aciduria.

Urinary excretion of uric acid, hypoxanthine, allantoin, and urea was measured in sheep (Polish Merino, about 20 kg b.w.) with experimental orotic aciduria.

[Effect of volatile fatty acid concentration in the rumen on blood flow in the mesenteric vessels of sheep].

The studies were performed on sheep with chronic rumen fistulae and implanted electromagnetic recorders of blood flow in the anterior mesenteric vein and the anterior mesenteric artery. The animals were fed the diet consisting of sugar beet, urea and mineral salts (diet I) or sugar beet and mineral salts (diet II--nitrogen deficient). The diet caused an increase of blood flow in the mesenteric artery and the mesenteric vein: this increase reached the highest level after 2 hours since the application of the diet.

The depressive action of ammonium chloride on the hepatic blood flow in sheep.

Using the 133Xe clearance method it is shown that NH4Cl infusion into the anterior mesenteric vein decreased capillary blood flow in the liver. Phentolamine completely and propranolol partially prevented the depressive action of NH4Cl on hepatic blood flow. NH5Cl infused into the jugular vein provoked a slight increase in the hepatic blood flow.