AIMTo investigate the mechanisms of 17beta-estradiol on the production of endothelin-1 in vascular smooth muscle cells.

METHODSAfter incubation VSMC with various concentrations of 17beta-estradiol (10(-9) - 10(-7) mol/L) or plus L-NAME(10(- 6) mol/L) for different times, the concentration of endothelin-1 was measured. At the same time, the activity of endothelin converting enzyme-1 was analyzed, and the expression of preproET-1mRNA was measured by RT-PCR.

RESULTSIn basal conditions, 17beta-estradiol could inhibit the production of endothelin-1 in VSMC, and the action of 17beta-estradiol had nothing to do with the activity of endothelin converting enzyme-1. L-NAME inhibited the effect of 17-estradiol on the production of endothelin-1 in VSMC. RT-PCR results showed that 17-estradiol inhibited the preproET-1 mRNA expression, and whereas L-NAME reversed this action of 17beta-estradiol.

CONCLUSIONIn basal conditions, 17beta-estradiol decreases the preproET-1 mRNA expression through NO-pathway to inhibit the production of endothelin-1 in cultured VSMC.

Animals ; Cells, Cultured ; Endothelin-1 ; biosynthesis ; Estradiol ; pharmacology ; Muscle, Smooth, Vascular ; cytology ; drug effects ; metabolism ; Myocytes, Smooth Muscle ; drug effects ; metabolism ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; drug effects

OBJECTIVE: To evaluate the nature and imaging appearance of incidental enhancing breast lesions detected on a routine contrast-enhanced chest CT. MATERIALS AND METHODS: Twenty-three patients with incidental enhancing breast lesions on contrast-enhanced chest CT were retrospectively reviewed. The breast lesions were reviewed by unenhanced and enhanced CT, and evaluated by observing the shapes, margins, enhancement patterns and backgrounds of breast lesions. A histopathologic diagnosis or long-term follow-up served as reference standard. RESULTS: Sixteen (70%) patients had malignant breast lesions and seven (30%) had benign lesions. In 10 patients, the breast lesions were exclusively detected on contrast-enhanced CT. Using unenhanced CT, breast lesions with fibroglandular backgrounds were prone to be obscured (p < 0.001). Incidental primary breast cancer showed an non-significant trend of a higher percentage irregular margin (p = 0.056). All of the four incidental breast lesions with non-mass-like enhancement were proven to be malignant. CONCLUSION: Routine contrast-enhanced chest CT can reveal sufficient details to allow for the detection of unsuspected breast lesions, in which some cases may be proven as malignant. An irregular margin of incidental enhancing breast lesion can be considered a suggestive sign of malignancy.
Aged ; Breast Diseases/radiography ; Breast Neoplasms/*radiography/secondary ; *Contrast Media ; Female ; Humans ; *Incidental Findings ; Iohexol/*analogs & derivatives/diagnostic use ; Middle Aged ; *Radiography, Thoracic ; *Tomography, X-Ray Computed