Distribution and molecular form of immunoreactive big endothelin-1 in porcine tissue.
In the present study a specific and sensitive radioimmunoassay for big endothelin-1 was developed. Half maximal inhibition of binding of radioiodinated big endothelin-1 was observed at 58 pg/tube and big endothelin-1 was detectable as low as 2 pg/tube. With this assay, the regional distribution of big endothelin-1 was determined in porcine tissue and compared to the distribution of an immunoreactive endothelin. Considerable amount of immunoreactive big endothelin-1 was observed in the aortic intima (0.84 +/- 0.094 pg/mg wet tissue; mean +/- S.D.) and the lung (0.47 +/- 0.055), but there was a low concentration in other tissue including the kidney inner medulla, which has been shown to be abundant in immunoreactive endothelin. Furthermore the molecular form of immunoreactive big endothelin-1 in aortic intima was found to be big ET-1[1-39], but the molecular form of major immunoreactive big endothelin-1 in the lung is big endothelin-1[22-39] with big endothelin-1[1-39] being minor.
First Department of Internal Medicine, Miyazaki Medical College, Japan.
K
K
Kitamura
T
T
Yukawa
S
S
Morita
Y
Y
Ichiki
T
T
Eto
K
K
Tanaka
D000595:Amino Acid Sequence; D000818:Animals; D001011:Aorta / Q000378:metabolism; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D016232:Endothelins; D008168:Lung / Q000378:metabolism; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010455:Peptides / Q000378:metabolism*; D013552:Swine
D016232:Endothelins; D010455:Peptides