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PubMed1975

The effects of subacute and chronic exposure to 4-aminopyridine on reproduction in coturnix quail.

When male and female coturnix quail (Coturnix coturnix) were given a single subacute oral dose (5.62 mg/kg) of the avian frightening agent 4-aminopyridine (4AP) and paired with untreated mates, there was no effect on the reproductive performance of males; egg production of females was reduced the third week after treatment but recovered during the fourth week. Chronic exposure to 31.6, 100, and 316 ppm of 4AP in the diet of mated pairs did not affect reproductive performance during or after the 4- or 6-week period the chemical was fed, but no birds fed 1,000 ppm produced live chicks after treatment began and all died within 3 weeks. The 28-day LC50 of 4AP was determined to be 447 ppm for male coturnix and 562 ppm for females. F1 progeny from quail fed 31.6, 100, and 316 ppm 4AP and randomly mated at maturity showed no reproductive effects from their parents' exposure.

Animals↗
PubMed1978

Some observations on the calcium ion binding to the eggshell matrix.

The calcified matrix of the hen eggshell has been demineralized with the EDTA. Aliquots of this material are soluble in water and have been characterized by column chromatography and by chemical analyses. Of particular interest is the high hexosamine and uronic acid content, which confirms the protein-polysaccharide nature of this water-soluble material. The calcium ion binding to the eggshell matrix has been studied by the equilibrium dialysis technique at different pH values, with both free and blocked carboxylic groups. The material with the free carboxylic side chain groups binds more calcium ions with increasing pH value. When the carboxylic groups have been previously blocked with a water-soluble carbodiimide, the calcium ion binding rapidly decreases. The residual capacity to bind calcium ions in the material with the carboxylic functions modified is probably due to the sulfate ions. In agreement with previous observations on other calcified substrates, the calcium ion binding seems to depend on the presence of ionized carboxylic functions of the matrix.

Amino Acids↗
PubMed1992

Effects of p,p'-DDE and some other chlorinated hydrocarbons on the formation of prostaglandins by the avian eggshell gland mucosa.

Some structurally related chlorinated hydrocarbons were investigated for their effects on the production of prostaglandins by the eggshell gland mucosa of ducks and domestic fowl. Formation of PGF2 alpha, PGE2 and TxB2 by homogenates of domestic fowl eggshell gland mucosa was significantly inhibited by in vitro addition of p,p'-DDE, Arochlor 1242 and, to a lesser extent, Arochlor 1260, but not by p,p'-DDT and o,p'-DDE. Comparatively, in duck eggshell gland mucosa homogenates, synthesis of the same prostaglandins was somewhat more sensitive to inhibition by 5 microM p,p'-DDE added in vitro. Eggshell gland mucosa synthesized significantly more PGF2 alpha, PGE2 and TxB2 than did the mucosa of the magnum and isthmus regions of the oviduct. Duck eggshell gland mucosa homogenates synthesized significantly more prostaglandins than similar homogenates from the domestic fowl, and, considering the former synthesis of PGF2 alpha was significantly higher when ducks were slaughtered at 08:00 than at 16:00 hours. In ducks, dietary administration of 40 ppm, p,p'-DDE for 45 days resulted in 21% eggshell thinning compared to the contemporary control values. This treatment also resulted in notable effects in homogenates of the eggshell gland mucosa, as compared to controls: Ca2+ uptake was reduced by 43%, synthesis of PGF2 alpha, PGE2 and TxB2 was reduced by 26%, 38% and 53%, respectively; the Ca content was increased to 145%. The role of p,p'-DDE in inhibiting prostaglandin formation in the eggshell gland is discussed as a mechanism of the eggshell thinning action of this chlorinated hydrocarbon.

Animals↗