Abstract
A highly sensitive radioimmunoassay has been developed for measuring plasma growth hormone (GH) concentrations in the African catfish (Clarias gariepinus). The lower detection limit of the assay was 0.1 ng/ml and the standard curve had an ED50 value of 0.5 ng/ml. The validity of the assay was established and the effects of several neurotransmitters on the release of GH were examined. In vitro experiments, using a static culture system for dispersed pituitary cells, demonstrated that the GH release in African catfish was affected by growth hormone-releasing hormone and somatostatin. Single intraperitoneal injections with a dopamine agonist, apomorphine, produced significant and dose-dependent increases in plasma GH levels. Unlike carp, goldfish, and tilapia, a super-active analogue of salmon gonadotrophin-releasing hormone did not alter plasma GH levels in African catfish.
Publication types
-
Comparative Study
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Animals
-
Apomorphine / administration & dosage
-
Catfishes
-
Cells, Cultured
-
Cross Reactions
-
Dopamine Agonists / administration & dosage
-
Dose-Response Relationship, Drug
-
Female
-
Gonadotropin-Releasing Hormone / administration & dosage
-
Gonadotropin-Releasing Hormone / analogs & derivatives
-
Growth Hormone / analysis*
-
Growth Hormone / drug effects
-
Growth Hormone / immunology
-
Growth Hormone / metabolism
-
Hormone Antagonists / pharmacology
-
Immune Sera / immunology
-
Immunohistochemistry
-
Injections, Intraperitoneal
-
Iodine Radioisotopes
-
Male
-
Pituitary Gland / anatomy & histology
-
Pituitary Gland / chemistry
-
Pituitary Gland / cytology
-
Pituitary Gland / immunology
-
Rabbits
-
Radioimmunoassay / methods
-
Reproducibility of Results
-
Sensitivity and Specificity
-
Sermorelin / pharmacology
-
Somatostatin / pharmacology
Substances
-
Dopamine Agonists
-
Hormone Antagonists
-
Immune Sera
-
Iodine Radioisotopes
-
Gonadotropin-Releasing Hormone
-
Somatostatin
-
Sermorelin
-
Growth Hormone
-
Apomorphine