Radioimmunoassay for somatostatin receptor type 2.
OBJECTIVE
To develop radioimmunoassay for somatostatin receptor type 2 (SSTR2) and search for its presence in certain rat tissues.


METHODS
Anti-SSTR2 antiserum has been raised in New Zealand white rabbits immunized with a conjugate of synthetic SSTR2 with bovine serum albumin. Radioiodination of SSTR2 was performed by chloramin T method followed by purification of radioiodinated material on Sephadex G-25 column.


RESULTS
The obtained antibody did not crossreact with SSTR1, SSTR3, SSTR4, SSTR5, hypothalamic hormones, pituitary hormones, neuropeptides or gut hormones. The assay was performed with a double antibody system. SSTR2 was extracted from the tissues with acid acetone. The dilution curve of acid acetone-extracts of rat hypothalamus in the radioimmunoassay system was parallel to the standard curve. The recovery of tissue SSTR2 was about 89 %, and the intra-assay and inter-assay variations were 4.9 % and 7.8 %, respectively. SSTR2 was found in the hypothalamus, cerebrum, cerebellum, pituitary, stomach and testis.


CONCLUSIONS
These data suggest that this assay system is suitable for the estimation of SSTR2 in the tissues.
Hirooka
Y
Y
Department of Laboratory Medicine, Aichi Medical University School of Medicine, Nagakute, Aichi, Aichi, 480-1195 Japan. yhirooka@aichi-med-u.ac.jp
Tagaki
J
J
Ikai
R
R
Kawai
H
H
Nakamura
R
R
Nakayashiki
A
A
Habu
S
S
Otake
K
K
Mori
Y
Y
Gotoh
M
M
Nogimori
T
T
D000096:Acetone; D000818:Animals; D000918:Antibody Specificity; D001923:Brain Chemistry; D002531:Cerebellum / Q000737:chemistry; D007031:Hypothalamus / Q000737:chemistry; D007106:Immune Sera; D007457:Iodine Radioisotopes; D007553:Isotope Labeling; D008297:Male; D010902:Pituitary Gland / Q000737:chemistry; D011786:Quality Control; D011817:Rabbits; D051381:Rats; D017208:Rats, Wistar; D017481:Receptors, Somatostatin / Q000032:analysis*; D013270:Stomach / Q000737:chemistry; D013687:Telencephalon / Q000737:chemistry; D013737:Testis / Q000737:chemistry
D007106:Immune Sera; D007457:Iodine Radioisotopes; D017481:Receptors, Somatostatin; D000096:Acetone; C093733:somatostatin receptor 2