Isoproterenol activation of prostaglandin production in guinea-pig airway muscle preparations from immature and mature animals.
The aim of this study was to evaluate the capacity of isoproterenol to activate the cyclooxygenase pathway in tracheal and bronchial tissues derived from immature (198 +/- 4 g, N = 12) and mature (997 +/- 28 g, N = 12) guinea-pigs. Immunoreactive PGE2 and PGF2 alpha were measured in bath samples obtained during resting tone and when tissues had been maximally contracted or relaxed. Results from these experiments showed that histamine contractions were significantly greater in tracheal than in bronchial preparations, an effect which was independent of age. Isoproterenol and theophylline were equiactive in relaxing basal tone of tracheal and bronchial tissues when data for each tissue type was compared with results in the different age groups. This effect was also independent of age. When results were normalized for tissue wet weights, the quantities of prostaglandins produced in tissues from mature guinea-pigs were less than those generated in similar tissues derived from immature animals. These data indicate significant modifications in basal prostaglandin production in tissues from immature and mature guinea-pigs. In addition, isoproterenol stimulated prostaglandin production in airways from immature and mature animals whereas theophylline did not alter the basal production.
Labat
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C
Departement de Pneumologie Hopital Cochin, Paris, France.
Braunstein
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G
Brink
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C
D000375:Aging; D000818:Animals; D001980:Bronchi / Q000201:enzymology / Q000254:growth & development*; D015237:Dinoprost / Q000096:biosynthesis; D015232:Dinoprostone / Q000096:biosynthesis; D004789:Enzyme Activation / Q000187:drug effects; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology*; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*; D011453:Prostaglandins / Q000096:biosynthesis*; D013806:Theophylline / Q000494:pharmacology; D014132:Trachea / Q000201:enzymology / Q000254:growth & development*
D011453:Prostaglandins; D006632:Histamine; D015237:Dinoprost; D013806:Theophylline; D011451:Prostaglandin-Endoperoxide Synthases; D015232:Dinoprostone; D007545:Isoproterenol