Effects of consecutive thiouracil exposures in the juvenile and adult single comb White Leghorn chicken on body weight and reproductive performance

Abstract

The effects of consecutive exposures to dietary thiouracil (TU) in juvenile and adult Single Comb White Leghorn chickens on plasma thyroxine (T4) concentrations, egg production (EP), egg weight (EW), concentrations eggshell quality were determined. Thiouracil was provided in the feed at levels of 0, 0.1, or 0.2% (PTRT) from 0 to 6 wk of age and at levels of 0 or 0.1% (TRT) from 32 to 38 wk of age. Body weight gain was simulated but T4, EW, EP, and eggshell quality were generally reduced by 0.1% TU TRT. However, TU PTRT alleviated a latent depressing effect of TU TRT on BW after 38 wk of age. Thiouracil PTRT, particularly at the 0.2% level, induced significant decreases in EW but increased EP between 32 and 50 wk. The effects of early thyroid suppression in juveniles with TU PTRT on the subsequent reproduction of adults were primarily in response to a delay in the onset of sexual maturity, and not directly to prolonged responses in T4 or BW that extended into lay.

Effect of the sulfur atom on S2 and S4 positions of the uracil ring in different DNA:RNA hybrid microhelixes with three nucleotide base pairs

“…Although the nucleobases with sulfur appear with the same distribution of acceptors and donors groups that the natural nucleobases with oxygen, however, the thiobases cause specific changes in the properties. Thus, a large number of thiouracil derivatives have been used in numerous pharmacological applications, and also attract attention for anti‐HIV, heart diseases treatments, and others . Nucleosides containing 2‐thiouracil are modified units that appear essentials in natural and synthetic nucleic acids .…”

Experimental study on the thermochemistry of 2-thiouracil, 5-methyl-2-thiouracil and 6-methyl-2-thiouracil

“…5-Substituted 2-(thiomethyl)uracils were successfully used in the synthesis of isocytosine derivatives related to the H 2 -receptor histamine antagonists [17]. 6-Methyl-2-thiouracil induces modifications in the thyroid, such as, an increase of the hypothyroidism effect on blood [18] or a dietary product due to the effects on thyroid activity suppression [19,20].…”

Thiouracils: Acidity, Basicity, and Interaction with Water

“…Continuous interest has been expressed in the structural properties of modified nucleic acid bases because most of them have been widely implicated for a variety of biological activities. − For example, incorporation of heavier atoms into DNA bases leads to a therapeutically important class of nucleic acid component. − One important class of such derivatives originates from the substitution of the thio group in place of the exocyclic oxo group in both purines and pyrimidines. More specifically, 2-thiouracils are frequently studied for their numerous pharmacological and biochemical capabilities such as mutagenic, anticancer, and antithyroid activities. − 2-Thiouracil constitutes an important derivative of the thiated pyrimidines. It is used as the cross-linking agent in RNA transcriptional regulation and exists in prokaryotic tRNAs. , Thiobases influence the structure of DNA, although hydrogen bonding involving thioguanine should not differ dramatically from guanine-containing complexes.…”

“…More specifically, 2-thiouracils are frequently studied for their numerous pharmacological and biochemical capabilities such as mutagenic, anticancer, and antithyroid activities. [8][9][10][11][12][13][14][15][16][17][18][19][20] 2-Thiouracil constitutes an important derivative of the thiated pyrimidines. It is used as the cross-linking agent in RNA transcriptional regulation 21 and exists in prokaryotic tRNAs.…”