Outpatient postconceptional fertility control with vaginally administered 15(S)15-methyl-PGF2α-methyl ester

SummaryThe effects of a number of synthetic arginyl- and lysyl-compounds on clotting and fibrinolysis have been studied. The lysyl derivatives had no significant effect on the clotting of recalcified plasma or recalcified euglobulin preparations, but tosyllysine (TL) and tosyllysine methyl ester (TLME) were very effective inhibitors of fibrinolysis. Certain arginyl-peptides (in particular, tosylarginylsarcosine methyl ester) were very effective at delaying clotting in these systems. These same substances gave rise to an exaggerated thrombin production, however, evidently by interfering with the natural thrombin activation of plasma antithrombin(s).

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Activity of Plasmin and Streptokinase-Activator on Substituted Arginine and Lysine Esters

Thrombosis and Haemostasis ◽

10.1055/s-0038-1655623 ◽

1966 ◽

Vol 16 (01/02) ◽

pp. 018-031 ◽

Cited By ~ 13

Author(s):

S Sherry ◽

Norma Alkjaersig ◽

A. P Fletcher

Keyword(s):

Molecular Structure ◽

Methyl Ester ◽

Comparative Studies ◽

Esterase Activity ◽

Methyl Esters ◽

Hydrolytic Activity ◽

The Other ◽

Other Hand

SummaryComparative studies have been made of the esterase activity of plasmin and the streptokinase-activator of plasminogen on a variety of substituted arginine and lysine esters. Human plasmin preparations derived by different methods of activation (spontaneous in glycerol, trypsin, streptokinase (SK) and urokinase) are similar in their esterase activity; this suggests that the molecular structure required for such esterase activity is similar for all of these human plasmins. Bovine plasmin, on the other hand, differs from human plasmin in its activity on several of the substrates studied (e.g., the methyl esters of benzoyl arginine and tosyl, acetyl and carbobenzoxy lysine), a finding which supports the view that molecular differences exist between the two animal plasmins. The streptokinase-activator hydrolyzes both arginine and lysine esters but the ratios of hydrolytic activity are distinct from those of plasmin and of other activators of plasminogen. The use of benzoyl arginine methyl ester as a substrate for the measurement of the esterase activity of the streptokinase-activator is described.

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EFFECT OF FEEDING ETHINYLOESTRADIOL FOR VARIOUS PERIODS BEFORE MATING ON REPRODUCTION IN THE HAMSTER

Acta Endocrinologica ◽

10.1530/acta.0.0700582 ◽

1972 ◽

Vol 70 (3) ◽

pp. 582-590

Author(s):

B. K. Davis ◽

I. Noske ◽

M. C. Chang

Keyword(s):

Single Dose ◽

Pregnancy Rate ◽

Fertility Control ◽

Normal Pregnancy ◽

Oestrous Cycle ◽

The Other ◽

Feeding Schedule ◽

Crown Rump Length ◽

Essentially Normal ◽

Effect Of Feeding

ABSTRACT Ethinyloestradiol (EO) fed for various periods before mating to female hamsters affected the timing of mating and pregnancy rate. Slight effects on ovulation, foetal-crown rump length and resorption may have occurred, but effects on implantation were not apparent among pregnant hamsters. The response observed depended upon the feeding schedule adopted: hamsters fed 2.5 mg EO in a single dose, on day 3 before mating, mated normally but had a significantly lower pregnancy rate; on the other hand, animals fed 2.5 mg EO (0.21 mg/day) over three oestrous cycles, days 14–3 before mating, showed variations in the time of mating but had an essentially normal pregnancy rate; and, a group of hamsters who received the same total amount of EO (0.63 mg/day) over one oestrous cycle, days 6–3 premating, showed untowards effects by the steroid on both the timing of mating and pregnancy rate. The implications of these results are considered in relation to fertility control.

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