Enzyme immunoassay of gonadotropin releasing hormone in the canine hypothalamus and plasma using monoclonal antibodies.
A monoclonal antibody against gonadotropin releasing hormone (GnRH)-BSA was used in the development of a sensitive enzyme immunoassay of GnRH in the canine hypothalamus and in plasma. The method had a limit of detection of 4 pg per sample. The intra- and interassay coefficients of variation were < 7.3% and < 11.0%, respectively. Acid extracts of hypothalamus produced a dose response curve which was parallel to that obtained with the synthetic GnRH standard. Checking cross reactivity of various fragments of GnRH revealed that the antibody was formed predominantly against the C-terminal end of GnRH. Thyrotropin-releasing hormone and other hypothalamic hormones did not appear to influence the assay. In male dogs, hypothalamic GnRH levels increased with age up to 4 months, then fell to a plateau from 6 months to 2 years. The time required for a 50% reduction in plasma levels following intravenous administration of synthetic GnRH to five adult male dogs was 2.2 +/- 0.1 (SEM) min.
Department of Animal Reproduction, College of Agriculture, University of Osaka Prefecture, Japan.
T
T
Inaba
S
S
Shimada
M
M
Gonda
J
J
Mori
T
T
Tokunaga
M
M
Geshi
R
R
Torii
D000375:Aging / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D004285:Dogs / Q000378:metabolism*; D007987:Gonadotropin-Releasing Hormone / Q000032:analysis* / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics; D006207:Half-Life; D007031:Hypothalamus / Q000737:chemistry*; D007124:Immunoenzyme Techniques; D008297:Male; D008969:Molecular Sequence Data
D000911:Antibodies, Monoclonal; D007987:Gonadotropin-Releasing Hormone