title: Chromogranin A proteolysis to generate beta-granin and WE-14 in the adenohypophysis during the rat oestrous cycle.
abstract: Immunohistochemical analysis of the male and female rat adenohypophysis revealed that chromogranin A (CgA), beta-granin and WE-14 immunostaining was localised to follicle stimulating hormone (FSH) producing cells, while luteinizing hormone (LH) producing cells exhibited chromogranin A and beta-granin immunostaining. The intensity of chromogranin A, beta-granin and WE-14 immunostaining exhibited variation during the oestrous cycle; weak immunostaining was observed during proestrous and oestrous, corresponding with the lowest cellular concentration of luteinizing and follicle stimulating hormone. Chromogranin A and beta-granin immunostaining were similar in both the male and female (at dioestrous), however, a larger number of more intense WE-14 immunopositive cells were evident in the male adenohypophysis relative to the female at any stage of the cycle. The tissue and plasma concentrations of beta-granin and WE-14 immunoreactivity fluctuated throughout the oestrous cycle. Maximum and minimum beta-granin and WE-14 tissue concentration counterpoised the latent maximum and minimum plasma concentration. Chromatographic analysis of adenohypophysis extracts revealed the degree of chromogranin A proteolysis throughout the oestrous cycle; in contrast, plasma profiles consistently possessed a large chromogranin A-like immunoreactant. This data suggests that chromogranin A biosynthesis, proteolysis and the secretion of its derived peptides parallels that of the gonadotroph hormones throughout the oestrous cycle.
authors.affiliation: School of Medicine, Obstetrics and Gynaecology, Queen's University of Belfast, Institute of Clinical Science, Grosvenor Road, Belfast, BT12 6BJ, Northern Ireland, UK. c.mcvicar@qub.ac.uk
authors.forename: Carmel Mary
authors.initials: CM
authors.lastname: McVicar
authors.forename: Rodat Therese
authors.initials: RT
authors.lastname: Cunningham
authors.forename: Neil
authors.initials: N
authors.lastname: McClure
authors.forename: William James
authors.initials: WJ
authors.lastname: Curry
mesh_terms: D000818:Animals; D002845:Chromatography; D053379:Chromogranin A; D002864:Chromogranins / Q000378:metabolism* / Q000494:pharmacology*; D030762:Estrous Cycle; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism; D007150:Immunohistochemistry; D007986:Luteinizing Hormone / Q000378:metabolism; D008297:Male; D009363:Neoplasm Proteins / Q000378:metabolism*; D010903:Pituitary Gland, Anterior; D011499:Protein Processing, Post-Translational; D011863:Radioimmunoassay; D051381:Rats; D017208:Rats, Wistar
chemical_list: D053379:Chromogranin A; D002864:Chromogranins; D009363:Neoplasm Proteins; C046560:beta-granins; C506153:chromogranin A, rat; C074381:chromogranin A-derived peptide, WE-14; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone