B. E. Fry

Cadmium Toxicity Decreased by Dietary Ascorbic Acid Supplements

Feeding the environmental toxicant cadmium to young Japanese quail for 4 weeks produced growth retardation, severe anemia, low concentrations of iron in the liver, and high concentrations of cadmium in the liver. Dietary ascorbic acid supplements almost completely prevented the anemia and improved the growth rate but did not markedly alter concentrations of iron or cadmium in the liver.

EFFECTS OF VITAMIN C AND IRON ON CADMIUM METABOLISM

Toxic levels of dietary cadmium (5-200 ppm) interfered with iron absorption and produced an iron deficiency. Supplements of iron (particularly the divalent form) and ascorbic acid protected against the cadmium. With very low levels of dietary cadmium (about 0.06-0.08 ppm), typical of those in the diets of humans, supplements of iron(II) and ascorbic acid markedly decreased cadmium concentrations in the liver, kidney, and small intestine. Iron deficiency changed the distribution of cadmium within the body. The effect of ascorbic acid on cadmium metabolism appears to depend primarily, if not entirely, on its influence in improving iron absorption. Maintenance of modest iron stores appears to be very important in minimizing cadmium absorption.

Enhancement of Acute Myocardial Lesions by Asthma Drugs in Rats

Asthma morbidity and mortality have risen significantly in the last 10 years. The reasons for the increase are multifactorial. One proposed explanation is possible myocardial toxicity arising from the use of β-agonists alone or in combination with methylxanthines. Previous studies have shown that β-agonists given alone and β-agonist/methylxanthine combinations given at higher than recommended clinical doses induced dose-related cardiotoxicity and sudden death in rats. The objective of the present study was to determine whether or not β-agonists given alone and in combination with methylxanthines at recommended clinical doses also induce cardiotoxicity and sudden death in rats. The β-agonists, isoproterenol hydrochloride (15 μg/kg), fenoterol hydrobromide (40 μg/kg), and terbutaline hemisulfate (0.4 mg/kg) were given in single sc doses separately and concurrently with the methylxanthines aminophylline hydrate (20 mg/kg) and caffeine (40 mg/kg), which were given ip to a susceptible animal model, the heavy Sprague-Dawley rat. β-agonist-induced myocardial toxicity (necrosis) was observed. The toxicity was enhanced by aminophylline resulting in the sudden death (most likely due to ventricular fibrillation) of some animals. A decrease in serum iron levels was observed in rats of all β-agonist and/or methylxanthine-treated groups.

Zinc-induced anemia in young japanese quail ameliorated by supplemental copper and iron

Abstract Studies were conducted to examine whether anemia induced in newly hatched Japanese quail by moderate dietary Zn supplements could be corrected by supplemental Fe, Cu, or Mg by 14 d of age. Low hemoglobin (Hb) was partially alleviated by increased levels of Fe or Cu, but normal Hb was obtained only with Fe plus Cu. Fe and Cu concentrations in the liver were decreased at 7 d, prior to the development of anemia by 13 d. Additional Mg had no effect on low Hb caused by Zn. Copper supplementation partially alleviated the growth depression and entirely prevented the lack of feather pigmentation that resulted from Zn toxicosis. Neither Fe nor Mg affected either of these parameters. These data indicate that both Fe and Cu status of an individual may be compromised by dietary Zn supplementation.

Changes in plasma zinc related to fasting and dietary protein intake of Japanese quail.

Summary Day-old Coturnix coturnix japonica of both sexes were fed a purified diet containing deficient, requirement, or excess amount of zinc (7, 25, or 75 mg of zinc per kg of diet, respectively) for 4 wk. The plasma zinc concentrations reflected the level of zinc intake during this time. All birds except non-fasted controls and one group of supplemented birds were fasted for 24 hr. There was no decrease in plasma zinc in the deficient birds after fasting; however, there was a significant decrease in birds receiving 25 or 75 mg of zinc per kg of diet. Following the fast, supplements consisting of complete diets or dietary components were fed, with or without added zinc (75 mg of zinc per kg of diet) for 4 hr. In birds that had received normal or excess zinc, there was a marked decrease in plasma zinc from the 24-hr fasting value when the supplement contained either soybean or egg white protein. When zinc was added to the supplement, the effect of protein on plasma zinc level was unchanged. Supplements of glucose or corn oil plus cellulose did not result in the marked lowering of plasma zinc that was observed with protein. Plasma zinc was significantly increased when zinc was added to the supplement of glucose or corn oil plus cellulose. Under conditions of rapid protein metabolism, it appears that one might expect a significant decrease in the plasma zinc level. The authors wish to thank Jesse J. Gantt, Geneva Clark, Francenia V. Grinnage, and Maggie Smith, Food and Drug Administration, for excellent technical assistance and care of the birds; and F. E. Calvert, Ralston Purina Co., who supplied lots of soybean protein selected for their low zinc content.

Production of Mg Deficiency Anemia by Zn and Phytate in Young Japanese Quail

An increase in dietary Zn to ameliorate the Zn deficiency produced by dietary phytic acid (PA) caused high mortality, decreased body weight, and elevated Fe in the liver and tibia of young Japanese quail by 14 d of age (Fox et al., 1985). Supplemental Mg prevented these adverse effects. Since marked anemia is a characteristic feature of Mg deficiency in the young quail (Tao et al., 1983), we investigated the effects of supplemental Fe in Mg-deficient birds and in those fed elevated Zn with PA.

Effects of Heat Treatment of Defatted Soy Flour Fed to Young Japanese Quail

Soy protein products, with versatile functional properties and good nutritional quality, are increasingly used in human foods. It is important to develop animal bioassays to assess the adequacy of processing to assure the safety and nutritive quality of these products. We observed that feeding a commercial fully toasted, defatted soy flour to young Japanese quail as the sole protein source resulted in poor growth, even with supplemental zinc (Fox et al., 1983). We investigated the effects of graded heat treatment of soy flour on growth, development, and mineral utilization in quail.