Copper absorption from stomach

Radioactive copper given by mouth to human subjects appears very rapibly in the blood (B9, C5, Jl), which indicates rapid absorption, probably from the upper parts of the small intestine and stomach. 

Some birds may not die immediately after drinking lethal cyanide solutions. Sodium cyanide rapidly forms free cyanide in the avian digestive tract (pH 1.3-6.5), whereas formation of free cyanide from metal cyanide complexes is comparatively slow. A high rate of cyanide absorption is critical to acute toxicity, and absorption may be retarded by the lower dissociation rates of metal-cyanide complexes. In Arizona, a red-breasted merganser (Mergus senator) was found dead 20 km from the nearest known source of cyanide, and its pectoral muscle tissue tested positive for cyanide. A proposed mechanism to account for this phenomenon involves weak-acid dissociable (WAD) cyanide compounds. Cyanide bound to certain metals, usually copper, is dissociable in weak acids such as stomach acids. It has been suggested that drinking of lethal cyanide solutions by animals may not result in immediate death if the cyanide level is... 

The rate of absorption of copper from the stomach (as CuCl2) has been studied by Osborn and Walshe [35] in a small series of patients with Wilson s disease and control subjects. Their findings, summarized in Table 4.1 show no difference between the concentration of radiocopper in either the plasma or the liver of the two groups during the immediate post-absorptive phase. This suggests that the rate of absorption of ionic copper is not markedly abnormal in Wilson s disease... 

---