A physiological role for the prostaglandins in parturition whereby these substances cause the uterus to contract by enhancing the myometrial response to circulating endogenous oxytocin can at present be only an interesting hypothesis, but the recent development of accurate methods of measuring plasma oxytocin and prostaglandin during labour may allow it to be tested soon.Encouraging results have been obtained with the potentiation of the uterine response exhibited when oxytocin and prostaglandin F2ca or prostaglandin E2 are administered simultaneously. This technique enables the prostaglandin to be infused at one-fifth the usual abortifacient dose and virtually eliminates gastrointestinal side effects. The preliminary work suggests that the abortifacient efficiency of this combinaton is high, probably because the prostaglandin enables the oxytocin to exert its very specific stimulatory action on the myometrium in an efficient manner. A more detailed study of the use of the potentiation of oxytocin and prostaglandin effects to produce mid-trimester abortion is underway.
SummaryBoth aspirin and phenacetin derivatives were shown to be nephrotoxic when administered to rats as a single intravenous injection. Phenacetin derivatives tended to produce more severe renal damage and to be nephrotoxic in smaller doses than aspirin derivatives. With the exception of a single derivative, the renal lesions were confined to the proximal convoluted tubule, even after administration of compounds which under other conditions have induced renal papillary necrosis.
vious data reported in the literature. [24][25][26][27][28] In this respect, however, further studies are in progress.
Experimental SectionIntrinsic viscosities were measured at 30°. Since the yields of all the poly(amide amines) listed were always practically quantitative, elemental analysis determinations were considered to be irrelevant. This polymerization being a polyaddition, in fact, the values obtained for the products could not be expected to be different from that of the monomeric mixtures. That under the conditions used no other reaction but polyaddition takes place between amines and compounds bearing activated double bonds has been previously demonstrated.29 Polymer Gr To a cooled (5°) solution of 1.94 g of 1,4-bisacryloyl-piperazine30 in 10 ml of ethanol, 9 ml of aqueous 1M ethanolamine and 1 ml of ethanolic 1 M «-dodecylamine were added under nitrogen. The mixture was thoroughly shaken and then kept in the dark at room temperature under a nitrogen atmosphere for 4 days. The solvents were then evaporated under reduced pressure and the product was dried at 45°under vacuum (0.1 mm). The yield was practically quan-
The nephrotoxicity of a number of aminophenols, quinols and catechols has been assessed from the extent of necrosis of proximal convoluted tubules produced by intravenous injection in rats, and the toxicity correlated with the oxidation-reduction potentials of the compounds.
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