Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0851184 (thinning)
 11,252 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thinning of the egg shell is produced by p-p'-DDT and DDE in several species of birds. A study was made of the effect of DDE administered in vitro and in vivo on the Ca2+ binding and Ca2+-Mg2+-activated ATPase of a homogenate of the egg shell gland of ducks (Anas platyrhynchos var.). The concentration of Ca2+ was 1 X 10(-4) M and that of MgATP 1 X 10(-3) M. In vitro, DDE in concentrations of 2-16 micrograms/ml of incubation medium inhibited the Ca2+-Mg2+-activated ATPase in a concentration-dependent manner, whereas Mg2+-activated ATPase was not affected by these concentrations. The Ca2+ binding by the homogenate was reduced by DDE in the same concentrations. The sodium azide sensitive Ca2+ binding was most sensitive. In vivo, DDE administered in a concentration of 40 mg/kg dry weight of the food for 45 days reduced the egg shell index by 18% in comparison to controls. After 45 days of treatment the DDE concentrations in the egg shell gland mucosa was 1.20 +/- 0.16 micrograms/g of wet weight, while no DDE was detected in the controls. The Ca2+-Mg2+-activated ATPase was reduced by 32%, whereas the Mg2+-ATPase was not changed. The Ca2+ binding by the homogenate was reduced by 29%, the sodium azide sensitive part being most vulnerable, DDE increased the total Ca content of the egg shell gland mucosa by 44%. Since Ca is transported against a concentration gradient between blood plasma, and the lumen of the shell gland, it is suggested that DDE, by inhibiting the Ca2+-Mg2+-activated ATPase, decreased the Ca translocation over the egg shell gland mucosa.
 ...
PMID:Effect of p-p'-DDE administered in vivo and in vitro on Ca2+ binding and Ca2+-Mg2+-ATPase activity in egg shell gland mucose of ducks. 612 33

The pesticide p-p'-DDT and its persistent metabolite p-p'-DDE cause thinning of the eggshells in several species of birds. In earlier investigations on ducks this thinning was found to be associated with a reduction of the ATP-dependent Ca2+ binding to a homogenate of the shell gland mucosal cells by DDE. The activity of a Ca2+-Mg2+-activated ATPase in the homogenate was also decreased on administration of DDE in vivo. We have therefore investigated the in vitro effects of some other chlorinated hydrocarbon pesticides of ecotoxicological interest on the ATP-dependent Ca2+ binding and the Ca2+-Mg2+-activated ATPase activity in a homogenate of the eggshell gland mucosa of the hen and determined the molar concentrations that produced 50% inhibition (=IC50). Several of the investigated compounds, namely toxaphene, chlordane, p-p'-DDD, o-p'-DDE, p-p'-DDT, methoxychlor and PCB (Arochlor 1242), had a similar IC50 to inhibit the Ca2+ binding as p-p'-DDE. Lindane, p-p'-DDA and biphenyl had an IC50 3.3-4 times higher and that of 2.4 D was 13.5 times higher than that of p-p'-DDE. When the IC50 of some of the compounds (p-p'-DDE, PCB, toxaphene, Lindane) was determined that decreased the Ca2+-Mg2+-activated ATPase of the homogenate it was found to be only 18 to 29 per cent of that needed to inhibit the Ca2+ binding by the homogenate. It is therefore probable that some other effect than inhibition of this enzyme is also involved in the Ca2+-binding process and affected by the compounds.
 ...
PMID:The inhibitory effect of some chlorinated hydrocarbon pesticides on the ATP-dependent Ca2+ binding of the particulate fraction of the eggshell gland mucosa cells. 613 49

The dynamic light scattering (DLS) method provides us with information about the apparent diffusion coefficient, Dapp, as well as the static scattering intensity, Is, of particles in solution. For long but thin rods with length L and diameter d, the dependence on L and d of Dapp is quite different from that of Is. By means of DLS we studied synthetic myosin filaments of rabbit skeletal muscle in solution at pH 8.3 and 10 degrees C. It appeared that Mg2+ ions induced thickening and lengthening of the filaments, whereas ATP (and ADP) induced thinning and shortening (depolymerization) of the filaments. When ATP was added to the filament preparation in the presence of Mg2+ ions, it was clearly observed that thinning of the filament (or splitting into subfilaments) occurred before shortening (or depolymerization).
 ...
PMID:Dynamic light scattering study of the effect of Mg2+ and ATP on synthetic myosin filaments. 769 13