Growth retardants examples

Sublethal effects in birds are similar to those in other species and include growth retardation, anemia, renal effects, and testicular damage (Hammons et al. 1978 Di Giulio et al. 1984 Blus et al. 1993). However, harmful damage effects were observed at higher concentrations when compared to aquatic biota. For example, Japanese quail (Coturnix japonica) fed 75 mg Cd/kg diet developed bone marrow hypoplasia, anemia, and hypertrophy of both heart ventricles at 6 weeks (Richardson et al. 1974). In zinc-deficient diets, effects were especially pronounced and included all of the signs mentioned plus testicular hypoplasia. A similar pattern was evident in cadmium-stressed quail on an iron-deficient diet. In all tests, 1% ascorbic acid in the diet prevented cadmium-induced effects in Japanese quail (Richardson et al. 1974). In studies with Japanese quail at environmentally relevant concentrations of 10 pg Cd/kg B W daily (for 4 days, administered per os), absorbed cadmium was transported in blood in a form that enhanced deposition in the kidney less than 0.7% of the total administered dose was recovered from liver plus kidneys plus duodenum (Scheuhammer 1988). 

The second compound with target AA had severe effects in different in vitro models (cardiac effects) but concentrations in vitro were much higher than those achieved in the preclini-cal mammalian studies. For example, the embryo-fetal toxicity study in rabbits was performed at 0.01, 0.025, and 0.25 mg/ kg/day by the oral route and resulted in maternal toxicity at all dose levels. The malformations observed in FETAX are presented in Table 4 those concerning the eyes, heart, and face (mouth, nares) were considered to be specific to the candidate compound. They were associated with growth retardation from 4 mg/L and marked embryo toxicity from 16 mg/L. 

The fetoplacental unit includes maternal and fetal placental circulations, other placental functions, umbilical cord and amniotic fluid. If chemicals — for example, vasoactive drugs — reduce the placental circulation or cause umbilical vasoconstriction, then marked prolonged action may cause fetal death from anoxia, but an action for less than 2 h in rodents may cause fetal growth retardation or... 

It is important to assess multiple outcomes, since a variety of effects may be correlated if a toxicant has multiple targets or if it has a latent effect. For example, intrauterine growth retardation is a well established correlate for many male reproductive problems, such as testicular cancer (Moller Skakkebaek, 1997), cryptorchidism and hypospadias ( et al., 1999b). The correlation of outcomes is a reflection of the intricate biological interactions of the human organism. 

Examples of disorders caused by mutations in the insulin receptor gene are leprechaunism and type A insulin resistance. A severe form of leprechaunism is due to mutations in both alleles of the insulin receptor gene. These patients exhibit insulin resistance, intrauterine growth retardation, and many other metabolic abnormalities. Patients with type A insulin resistance exhibit insulin... 

Metal ions are required for many critical functions in humans. Scarcity of some metal ions can lead to disease. Well-known examples include pernicious anemia resulting from iron deficiency, growth retardation arising from insufficient dietary zinc, and heart disease in infants owing to copper deficiency. The ability to recognize, to understand at the molecular level, and to treat diseases caused by inadequate metal-ion function constitutes an important aspect of medicinal bioinorganic chemistry. 

In CHEC-I the applications of pyridazines, cinnolines and phthalazines were briefly summarized <84CHEC-l(3B)i>. The antibacterial monamycins were cited as a rare example of naturally occurring pyridazines, while the growth retardant, herbicidal, and fungicidal activities of synthetic pyridazine derivatives are mentioned. Note was made of the hypotensive and antihypertensive activities of hydralazine and dihydralazine, and that in the cinnoline series only 3-and 4-amino derivatives exhibit biological activity. 

Plant hormone biosynthesis and metabolism are influenced and modified, too, as already mentioned, by a large number of typical secondary plant constituents of quite different structures (Eef. 5, 6). For instance, it has been shown that some oi-disubstituted acetic acid derivatives are active both as antiauxins and as inhibitors of the biosynthesis of cyclic terpenoids. Thus, some more simple model compounds synthesized by ourselves, for example substituted a-phenoxy-isobutyrio acids, are not only competitive auxin inhibitors but they are also able to inhibit both the gibberellin and sterol biosynthesis. The same is true for some well known plant growth retardants, such as CCO or AMO 1618, which are inhibitors of gibberellin biosynthesis both in plants and in Fus ium moniliforme, but at the same time they are inhibiting and modifying also the biosynthesis of steroids in the respective organisms as well as in animal in vitro systems (Eef. 29) ... 

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