Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0728731 (prematurity)
 7,134 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The present study was carried out to determine the ability of various pharmacological agents to selectively inhibit each cytosolic form of phosphodiesterase isolated from the longitudinal layer of human myometria near term. Among the drugs tested, zaprinast specifically inhibits the first form of PDE which hydrolyses both substrates (cAMP and cGMP) and is stimulated by the Ca2+-calmodulin complex. A second form of PDE specific for cAMP hydrolysis and Ca2+-calmodulin insensitive is only present during pregnancy. Rolipram is the most potent and selective inhibitor of this second form. It is also the most efficient compound to inhibit in vitro the spontaneous contractions of near term myometria. The double effect of rolipram suggests an important role of the second form of PDE in the mechanisms of contractility during the pregnancy. In addition rolipram or other derivatives might be of a therapeutic interest in the prevention of prematurity in so far as they are devoid of undesirable maternal and fetal side effects.
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PMID:Correlation between selective inhibition of the cyclic nucleotide phosphodiesterases and the contractile activity in human pregnant myometrium near term. 253 36

Serum immunoreactive parathyroid hormone (iPTH), ionized calcium, the urinary cyclic AMP/creatinine ratio (cAMP/Cr) and some indices of bone turnover (alkaline phosphatase (AP), serum osteocalcin, and the urinary total hydroxyproline/creatinine ratio (OH-P/Cr)) were measured in 26 preterm infants during the first 4 weeks of life. Despite of stimulated parathyroid gland activity cAMP/Cr, AP, osteocalcin and OH-P/Cr were low during the first week. Thereafter iPTH decreased, whereas cAMP/Cr, and the indices of bone turnover increased, reaching high-normal values (in comparison to full-term infants) during the second and third week of life. Serum iPTH was negatively correlated to cAMP/Cr in the first week (r = -0.61, p less than 0.01), whereas the relationship became positive during the second (r = 0.47, p less than 0.05) and third (r = 0.54, p less than 0.05) week of life indicating maturation of the renal response to PTH. The study supports the concept that in premature infants a transient pseudohypoparathyroid-like state is present during the first week of life reflecting an immaturity of renal and possibly bone response to PTH. This may be an etiological factor in hypocalcemia of prematurity.
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PMID:Evidence for transient peripheral resistance to parathyroid hormone in premature infants. 303 25

Methylxanthines like caffeine and theophylline have long been used to treat apnea of prematurity. Despite their success in stimulating neonatal breathing, their mechanism of action remains poorly understood. Methylxanthines can act as both non-specific adenosine receptor antagonists and inhibitors of cAMP-dependent phosphodiesterases, sarcoplasmic/endoplasmic reticulum calcium ATPases or receptor-coupled anion channels, depending on the dose used. Though there is evidence for methylxanthine action at the level of the carotid body, the consensus is that methylxanthines stimulate the respiratory centers of the brainstem. Here we used the in situ neonatal rat working heart-brainstem preparation and the ex vivo neonatal rat carotid body preparation to test the hypothesis that methylxanthines act at the level of the carotid body. We conclude that although the neonatal carotid body has active adenosine receptors, the effects of methylxanthine therapy are likely mediated centrally, predominantly via inhibition of cAMP-dependent phosphodiesterase-4.
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PMID:Methylxanthine reversal of opioid-induced respiratory depression in the neonatal rat: mechanism and location of action. 2491 66