Is protein synthesis necessary for prostaglandin production by guinea-pig endometrium?
The outputs of prostaglandin (PG) F-2 alpha, PGE-2 and 6-keto-PGF-1 alpha from Day-7 and Day-15 guinea-pig endometrium in culture were reduced by the inclusion of actinomycin D, cycloheximide and puromycin in the culture medium, with the output of PGF-2 alpha from Day-15 endometrium being particularly affected during the first 6 h of culture. The intrauterine administration of actinomycin D on Day 10 decreased the outputs of PGF-2 alpha and PGE-2, but not of 6-keto-PGF-1 alpha, from Day-15 endometrium in culture without affecting PG output from Day-15 myometrium in culture. Actinomycin D, cycloheximide and puromycin did not reduce PG output when superfused over the Day-7 and Day-15 guinea-pig uterus in vitro for 20 min, indicating that these compounds do not have a rapid inhibitory effect on endometrial PG synthesis. In fact, they tended to stimulate PG output during this 20-min period, with cycloheximide having a pronounced effect on PGE-2 output. The synthesis of secreted proteins, but not of cellular proteins, was greater by Day-15 than by Day-7 endometrium in culture. Actinomycin D, cycloheximide and puromycin inhibited the synthesis of secreted and cellular proteins by Day-7 and Day-15 endometrium in culture. Protein synthesis and PG synthesis in the endometrium were both inhibited to a greater extent by cycloheximide and puromycin than by actinomycin D. The intrauterine administration of actinomycin D on Day 10 reduced the syntheses of secreted and cellular proteins by Day-15 endometrium in culture. These findings indicate that the endometrial synthesis of PGs, particularly of PGF-2 alpha towards the end of the oestrous cycle, is dependent upon endometrial protein synthesis.
Department of Pharmacology, University of Edinburgh Medical School, UK.
S C
SC
Riley
N L
NL
Poyser
D015121:6-Ketoprostaglandin F1 alpha / Q000096:biosynthesis; D000818:Animals; D046508:Culture Techniques; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D015237:Dinoprost / Q000096:biosynthesis; D015232:Dinoprostone / Q000096:biosynthesis; D004717:Endometrium / Q000187:drug effects / Q000502:physiology*; D004971:Estrus; D005260:Female; D006168:Guinea Pigs; D011453:Prostaglandins / Q000096:biosynthesis*; D014176:Protein Biosynthesis; D011691:Puromycin / Q000494:pharmacology
D011453:Prostaglandins; D003609:Dactinomycin; D011691:Puromycin; D015121:6-Ketoprostaglandin F1 alpha; D003513:Cycloheximide; D015237:Dinoprost; D015232:Dinoprostone