THE UPTAKE OF LOCALLY APPLIED [6:7-3H]OESTRADIOL-17β BY THE VAGINA OF THE OVARIECTOMIZED MOUSE

1964 ◽  
Vol 30 (3) ◽  
pp. 337-346 ◽  
Author(s):  
L. MARTIN
Keyword(s):  
Biological Activity ◽  
Mode Of Action ◽  
Common Site ◽  
Tissue Levels ◽  
Ovariectomized Mouse ◽  
Receptor Sites ◽  
Site Of Action

SUMMARY Locally applied [6:7-3H]oestradiol was taken up rapidly by the vagina, at a rate similar to that of oestrone. Levels of radioactivity in the tissue reached their highest value 1–3 min. after application, and thereafter dropped slowly to reach 20% of the injected dose at 12 hr. This is in contrast to the behaviour of oestrone, the tissue levels of which fell rapidly over the first ½ hr. It is suggested that this difference accounts for the relative biological activity of the two hormones in the vagina, and results from varying affinities for receptor sites associated with the initiation of vaginal growth. Evidence is presented that oestrone, oestradiol and oestriol have a common site of action. Dimethylstilboestrol (DMS) converted the retention pattern of oestradiol to one resembling that of oestrone, and it is suggested that this involves blocking of receptor sites. The results are discussed in relation to the mode of action of oestrogens.

THE UPTAKE OF LOCALLY APPLIED [6:7-3H] OESTRONE BY THE VAGINA OF THE OVARIECTOMIZED MOUSE

1964 ◽  
Vol 30 (1) ◽  
pp. 41-51 ◽  
Author(s):  
L. MARTIN ◽  
B. BAGGETT
Keyword(s):  
Small Proportion ◽  
Mode Of Action ◽  
General Circulation ◽  
Simultaneous Application ◽  
Tissue Levels ◽  
Ovariectomized Mouse ◽  
Hormone Content ◽  
Site Of Action ◽  
Rapid Passage

SUMMARY Locally applied [6:7-3H]oestrone was rapidly taken up by the vagina. The hormone content of the tissue reached a peak 1 min. after application, and thereafter dropped rapidly to a level of 20–30% of the administered dose at 27 min., and more slowly to a level of 6% at 16 hr. The hormone content of the lumen decreased rapidly to near zero at the end of 27 min. Simultaneous application of dimethylstilboestrol (DMS) had little effect on tissue levels at 1 min., but significantly reduced the fraction retained for longer periods. Progesterone was without effect. It is suggested that, after its rapid passage into the vagina, a small proportion of the hormone is bound at the site of action, where it is retained for some hours. Any unbound hormone is lost to the general circulation within 30 min. The results are discussed in relation to the mode of action of oestrogens and anti-oestrogens.

scholarly journals The Mode of Action of Polyene Antibiotics; Induced Potassium Leakage in Candida albicans

Microbiology ◽  
2000 ◽  
Vol 81 (2) ◽  
pp. 325-330 ◽  
Author(s):  
S. M. HAMMOND ◽  
P. A. LAMBERT ◽  
B. N. KLIGER
Keyword(s):  
Candida Albicans ◽  
Mode Of Action ◽  
Liquid Membrane ◽  
Potassium Ions ◽  
Common Site ◽  
Potassium Efflux ◽  
Polyene Antibiotics ◽  
Site Of Action ◽  
Sensitive Electrode ◽  
Potassium Leakage

Summary: With a liquid membrane potassium-sensitive electrode it was shown that lethal concentrations of the polyene antibiotics amphotericin B, candicidin and nystatin caused leakage of 90% of non-bound potassium ions from Candida albicans. Accurate and rapid determinations of rates of potassium leakage were made directly in suspensions of Candida. Leakage patterns for the three polyenes were very similar, suggesting a common site of action. Differences were noted in the rates of potassium efflux with organisms from cultures of differing ages.

OESTROGEN – ANTI-OESTROGEN INTERACTION: EFFECT OF U11100A, MRL-41 (CLOMIPHENE) AND U11555A ON OESTROGEN INDUCED UTERINE GLYCOGEN AND PROTEIN SYNTHESIS IN THE RAT DURING DELAYED IMPLANTATION

1969 ◽  
Vol 62 (3) ◽  
pp. 489-497 ◽  
Author(s):  
Suresh Mohla ◽  
M. R. N. Prasad
Keyword(s):  
Protein Synthesis ◽  
Comparative Study ◽  
Interaction Effect ◽  
Mode Of Action ◽  
Biochemical Changes ◽  
Delayed Implantation ◽  
Receptor Sites ◽  
Made In

ABSTRACT A comparative study of three non-steroidal anti-oestrogens (a dihydronaphthalene, UlllOOA; a diphenylindene derivative, U-11555A and MRL-41 (clomiphene) was made in order to study their mode of action and their interaction with oestrogen induced biochemical changes in the uterus. Pretreatment with UlllOOA, clomiphene or U11555A effectively blocked the oestrogen induced increase in uterine glycogen and protein synthesis. However, all the three compounds tested were found to be uterotrophic; clomiphene also increased uterine glycogen while U11555A showed a transient oestrogenic action in increasing uterine protein. Clomiphene and U11100A have been shown to inhibit the uptake of oestrogen at the receptor sites. Our results may be interpreted as indicating that pretreatment with these compounds (U11100A, clomiphene or U11555A) blocked the uterine receptor sites in such a manner so as to render ineffective the action of oestrogen administered subsequently.

scholarly journals Thiol-Modification as Important Mode of Action for Allicin from Garlic (Allium sativum)

Proceedings ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 27 ◽  
Author(s):  
Martin C. H. Gruhlke
Keyword(s):  
Molecular Weight ◽  
Biological Activity ◽  
Active Compound ◽  
Mode Of Action ◽  
Allium Sativum ◽  
Cysteine Residues ◽  
Low Molecular Weight ◽  
Thiol Groups ◽  
Ancient Times ◽  
In Cells

Garlic is a common ingredient in food, normally used as spice but is also used since ancient times for its health beneficial activity. The thiosulfinate allicin is the first active compound in freshly damaged garlic tissue and reacts with thiol-groups. Hence, allicin is able to modify thiol groups, both of protein cysteine-residues and low-molecular weight thiols like glutathione. This thiol-modification is supposed to be an important mechanism for allicin’s biological activity. Here, the mechanisms and possible targets for allicin in cells are discussed.

scholarly journals AFN-1252 is a potent inhibitor of enoyl-ACP reductase from B urkholderia pseudomallei -Crystal structure, mode of action, and biological activity

2015 ◽  
Vol 24 (5) ◽  
pp. 832-840 ◽  
Author(s):  
Krishnamurthy Narasimha Rao ◽  
Anirudha Lakshminarasimhan ◽  
Sarah Joseph ◽  
Swathi U. Lekshmi ◽  
Ming-Seong Lau ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Biological Activity ◽  
Mode Of Action ◽  
Potent Inhibitor ◽  
Enoyl Acp Reductase

scholarly journals The effect of chemical modifications induced in insulin on the reactivity of the interchain disulphide bonds towards sodium sulphite

1968 ◽  
Vol 108 (2) ◽  
pp. 247-255 ◽  
Author(s):  
A. Massaglia ◽  
F. Pennisi ◽  
U. Rosa ◽  
S. Ronca-Testoni ◽  
C. A. Rossi
Keyword(s):  
Biological Activity ◽  
Mode Of Action ◽  
High Reactivity ◽  
Sodium Sulphite ◽  
Thiol Groups ◽  
Chemical Modifications ◽  
Amperometric Titration ◽  
Disulphide Bonds ◽  
Native Insulin

The reactivity of the three disulphide bridges of insulin towards sodium sulphite was studied by amperometric titration of the liberated thiol groups. In the native, acetylated or succinylated molecule two bridges react at pH7, but in the methylated or phenylcarbamoylated molecule only one bridge reacts. All three bridges react in all derivatives in 8m-urea or at pH9. Loss in biological activity parallels the loss in reactivity of one of the bridges during methylation. It is suggested that change in reactivity of the S·S bonds reflects the occurrence of a conformational modification of the protein. The possibility is discussed that the unusually high reactivity of the S·S bonds in native insulin depends strictly on the integrity of the native molecule, suggesting that S·S bonds are in some way involved in the hormone's mode of action.

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