title: Studies on the microheterogeneity of anterior pituitary follicle-stimulating hormone in the female rat. Isoelectric focusing pattern throughout the estrous cycle.
abstract: Anterior pituitary (AP) glands were removed from adult female rats at different times throughout the estrous cycle, and the isohormones of follicle-stimulating hormone (FSH) present within them were separated by isoelectric focusing in polyacrylamide gels (PAGE-IEF; pH range 3.0-8.0). Gel eluents were analyzed for FSH content by radioimmunoassay (RIA) and radioreceptor assay (RRA). All AP samples exhibited several peaks of FSH immunoactivity within a pH range of 6.2-4.0; the major peak constantly exhibited an isoelectric point (pI) of 4.9-4.5. To quantify differences in the IEF pattern of AP-FSH between the pituitaries collected during the different days of the cycle, each PAGE-IEF profile was divided into 7 regions (pI 7.0-6.3 = Area 1, 6.2-5.5 = Area 2, 5.4-5.0 = Area 3, 4.9-4.5 = Area 4, 4.4-4.0 = Area 5, 3.9-3.5 = Area 6, and less than 3.5 = Area 7), and the amount of FSH present within each was determined. In all APs collected at 0900 h of diestrus 1 (D1) and 2 (D2), proestrus (P), and estrus (E); at 1300 h of D1, D2 and E; at 2200 h of P; and at 0200 h of E, the majority of FSH immunoactivity (37-55% of total FSH on gel) focused within Area 4, whereas Areas 2 and 3 contained minor amounts of FSH activity (11-26% and 14-24%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000818:Animals; D002845:Chromatography; D004591:Electrophoresis, Polyacrylamide Gel; D004971:Estrus / Q000502:physiology*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000032:analysis*; D007525:Isoelectric Focusing; D010903:Pituitary Gland, Anterior / Q000032:analysis* / Q000502:physiology; D011863:Radioimmunoassay; D011869:Radioligand Assay; D051381:Rats
chemical_list: D005640:Follicle Stimulating Hormone