gamma-Butyrobetaine as a specific antagonist for carnitine in the development of the early chick embryo

The effect of gamma-butyrobetaine alone and with the addition of carnitine on the development of the early excised chick embryo has been studied. gamma-Butyrobetaine in appropriate amounts exerts an inhibitory effect which can be relieved or annulled by the inclusion of appropriate amounts of carnitine. This has been interpreted as a metabolite-antimetabolite relationship, in which the normal metabolite, carnitine, is antagonized by the structurally closely related gamma-butyrobetaine, and is regarded as evidence of an important role of carnitine in the metabolism of the developing chick embryo.

The lethal effect of endotoxins on the chick embryo

Inoculation of the CAM of the 10-day chick embryo with endotoxin preparations derived from the meningococcus and other Gram-negative microorganisms has been shown to result in multiple hemorrhages and death of the embryo within a few hours. Evidence has been presented to indicate that this lethal effect is specific for the general class of endotoxins derived from Gram-negative bacteria. Susceptibility to endotoxin was maximal in 10-day old embryos, and younger or older embryos showed little or no response. The optimal incubation temperature for the effect of endotoxin was 39.5 degrees C., and embryos incubated at 28 degrees C. were completely protected. The lethal effect was prevented by small amounts of cortisone, hydrocortisone, and 9-alpha fluorohydrocortisone, but not by cholesterol, desoxycorticosterone, or 1-dehydrocortisone.

The effect of L-triiodothyronine on the growth and development of embryonic chick limb-bones in tissue culture

Images