Use of a highly specific monoclonal antibody against the central variable amino acid sequence of mammalian gonadotropin releasing hormone to evaluate GnRH-I tissue distribution compared with GnRH-I binding sites in adult male rats.
OBJECTIVE
Recent evidence shows the existence of numerous isoforms of gonadotropin releasing hormone (GnRH), with high sequence homology and a core variable region. This raises the issue that previous GnRH distribution studies may have identified a variety of isoforms. This investigation was carried out to confirm the distribution and binding activity of GnRH-I only.


METHODS
A monoclonal antibody (7B101D10), with specificity for the core region of GnRH-I was used to stain formalin-fixed tissue sections from adult male Sprague-Dawley rats, while a biotinylated GnRH-I sequence was used with avidin-labelled HRP to evaluate regions of GnRH-I binding.


CONCLUSIONS
GnRH-I expression was only found in the hypothalamus, cerebellum, anterior/fore brain and in Sertoli cells, while, binding activity was only present in the pituitary, subendocardium and subepicardium, thymic lymphocytes, peripheral blood lymphocytes and neutrophils. There was overlap in the olfactory neurons, liver (Kupffer macrophages and hepatocytes), spleen (lymphocytes and dendritic cells), myocardium and testes (spermatozoa and Leydig cells) and this may be further evidence of the paracrine/autocrine activity of a neuropeptide.
Khan
Mohammad A H
MA
Department of Immunology, University of Strathclyde, Glasgow, UK.
Ferro
Valerie A
VA
Stimson
William H
WH
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D001665:Binding Sites / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D007987:Gonadotropin-Releasing Hormone / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D020033:Protein Isoforms / Q000276:immunology / Q000378:metabolism*; D051381:Rats; D011966:Receptors, LHRH / Q000276:immunology / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D020033:Protein Isoforms; D011966:Receptors, LHRH; D007987:Gonadotropin-Releasing Hormone