Cultured neurones from the mature bovine mediobasal hypothalamus contain LHRH but not catecholamine.
The in vitro culture of mature neurones from bovine mediobasal hypothalamus (MBH) is reported, providing a model for studies of mammalian neurosecretion at the cellular level. Explant tissue cultures of mature bovine MBH containing the arcuate nucleus were examined for LHRH, ACTH and catecholamines with a view to investigating the control of prolactin and gonadotropin secretion. LHRH immunoreactivity was found in both neuronal and non-neuronal cells in the outgrowth monolayer region of the explant. Neurones in this region appeared able to attach to a substrate and regenerate, in monolayer culture, well developed neurites characterized by beaded swellings as observed in vivo. Neither ACTH immunoreactivity nor catecholamine fluorescence was detected. Cultured neurones and astrocytes were labelled by tetanus toxin and anti-GFAP, respectively. Double labelling of cultures with tetanus toxin and anti-LHRH demonstrated the neuronal nature of many LHRH-immunoreactive cells. Radio-immunoassay data confirmed the presence of LHRH in the cultures but application of 60 mM KC1 failed to evoke hormone release. These studies have confirmed the view of previous workers that hypothalamic control of prolactin secretion in the bovine may be very different from that thought to occur in non-ruminants such as the rat and guinea pig. Finally, this work demonstrates that a cultured system from the mature bovine may prove a good model for study of neuronal regulation of gonadotropin secretion by the bovine mediobasal hypothalamus.
D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D000818:Animals; D001253:Astrocytes / Q000378:metabolism; D002395:Catecholamines / Q000378:metabolism; D002417:Cattle; D002478:Cells, Cultured; D005260:Female; D005455:Fluorescent Antibody Technique; D005904:Glial Fibrillary Acidic Protein; D007033:Hypothalamus, Middle / Q000378:metabolism*; D007381:Intermediate Filament Proteins / Q000378:metabolism; D008297:Male; D009474:Neurons / Q000378:metabolism; D010906:Pituitary Hormone-Releasing Hormones / Q000378:metabolism*; D013194:Staining and Labeling / Q000379:methods
D002395:Catecholamines; D005904:Glial Fibrillary Acidic Protein; D007381:Intermediate Filament Proteins; D010906:Pituitary Hormone-Releasing Hormones; D000324:Adrenocorticotropic Hormone