OBJECTIVE:To investigate if the vasoactive systems adrenomedullin (ADM) and endothelin-1 (ET-1) are expressed in human adipose tissues in children and in adults and to determine the distribution pattern of nitric oxide synthases (NOS). DESIGN AND SUBJECTS: Subcutaneous, mesenterial and omental adipose tissue specimens taken from 15 children (age 0.5-16 y, median 6 y) and 13 adults (age 43-79 y, median 60 y) were analyzed. The body mass indices (BMI) were within the normal range. All patients were normotensive, and were free of infectious disease, and metabolic or endocrine disorders. The specimens were taken during elective laparotomies after informed consent was obtained. MEASUREMENTS: ADM, ET-1, the endothelial (eNOS) and inducible (iNOS) NOS as well as two housekeeping genes were measured using quantitative real-time PCR. RESULTS: ADM gene expression was found at all locations, and was significantly higher in adults than in children (Po0.01 for subcutaneous and omental adipose tissue). ET-1 mRNA was distributed in a similar way, showing significantly higher levels in the subcutaneous and mesenterial adipose tissue sections of adults than of children. For eNOS, the adult patients exhibited a higher expression in subcutaneous and mesenterial specimens than the children (Po0.01 and Po0.05). The iNOS mRNA was increased in subcutaneous, mesenterial and omental adipose tissues in the adult cohort compared to the children's levels (Po0.05 to Po0.01). CONCLUSION: Human adipose tissue expresses many vasoactive substances including ADM and ET-1. In adults, the amounts of ET-1 and ADM as well as eNOS and iNOS mRNA are higher, possibly due to a physiological upregulation with increasing age. Although there are differences depending on the locations of the tissues, the expression patterns of the antagonists ADM and ET-1 are quite similar, indicative of a well-balanced pattern of local gene expression in normotensive individuals with normal body weight.

No abstract