Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0029713 (immaturity)
 4,335 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Genetic polymorphisms in the genes coding for drug metabolizing enzymes, drug transporters, and drug receptors are major determinants of an individual's response to drugs. The potential interactions of pharmacogenomics of renal drug transporters and drug receptors with renal drug disposition and the immature kidneys are briefly reviewed. Examples of gene polymorphisms seen in the RAAS (renin angiotensin system), beta-adrenergic receptors, dopamine receptors and cytochrome P450 and their potential clinical impact are discussed. The human newborn has deficient hepatic and renal drug metabolism and disposition. This immaturity in drug-handling capacity may potentially be superimposed to genetic polymorphisms determining drug metabolism and transport thereby substantially increasing interpatient variability in drug dose requirements and in drug responses in the newborn. Pharmacogenomics is a tool that can be used to individualize drug therapy in newborns to minimize adverse drug effects and to optimize efficacy.
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PMID:Pharmacogenomics and renal drug disposition in the newborn. 1520 Feb 52

The human neonatal period is characterized by renal immaturity with impaired capacity to regulate water and sodium homeostasis, resembling partial aldosterone resistance. Because aldosterone effects are mediated by the mineralocorticoid receptor (MR), we postulated that this hormonal unresponsiveness could be related to low MR expression in the distal nephron. We measured aldosterone and renin levels in umbilical cord blood of healthy newborns. We used quantitative real-time PCR and immunohistochemistry to analyze the expression of MR and key players of the mineralocorticoid signaling pathway during human and mouse renal development. High aldosterone and renin levels were found at birth. MR mRNA was detected in mouse kidney at d 16 postcoitum, peaking at d 18 postcoitum, but its expression was surprisingly very low at birth, rising progressively afterward. Similar biphasic temporal expression was observed during human renal embryogenesis, with a transient expression between 15 and 24 wk of gestation but an undetectable immunoreactive MR in late gestational and neonatal kidneys. This cyclic MR expression was tightly correlated with the evolution of the 11beta-hydroxysteroid dehydrogenase type 2 and the epithelial sodium channel alpha-subunit. In contrast, glucocorticoid and vasopressin receptors and aquaporin 2 followed a progressive and sustained evolution during renal maturation. Our study provides the first evidence for a low renal MR expression level at birth, despite high aldosterone levels, which could account for compromised postnatal sodium handling. Elucidation of regulatory mechanisms governing MR expression should lead to new strategies for the management of sodium waste in preterms and neonates.
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PMID:Low renal mineralocorticoid receptor expression at birth contributes to partial aldosterone resistance in neonates. 1947 42

Preterm birth (< 37 gestational weeks) reaches 10% of total births worldwide. Early exposure to an ex utero environment can alter organogenesis and maturation in the newborn. This early onset of events can further promote long-term developmental alterations and cardiovascular disease risks. Mechanisms activated during preterm birth and promoting such cardiovascular alterations have just recently been investigated. As a major candidate, the renin angiotensin aldosterone system (RAAS) can be acutely altered during preterm birth and persistently activated in later life. Further, RAAS alterations may occur as consequence of kidney and heart immaturity to promote adaptive responses, suggesting a dual role of this system on fetal and neonatal organogenesis. Furthermore, fetal or neonatal exposure to deleterious stress conditions can significantly impact on this dual RAAS role, contributing to the establishment of hemodynamic and structural alterations. In this review, clinical and experimental findings describing RAAS components and activation in relationship with preterm birth are discussed. Further clinical and experimental investigations on RAAS activation in the context of preterm birth are needed to better understand this dual role of RAAS on early development and on programming of risks to cardiovascular diseases.
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PMID:Preterm Birth and Renin-Angiotensin-Aldosterone System: Evidences of Activation and Impact on Chronic Cardiovascular Disease Risks. 2875 97


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