title: FSH and LH receptor concentrations in large ovarian follicles of beef cows in high and low levels of body condition at nine weeks post partum.
abstract: An experiment was conducted to determine whether or not the effect of body condition at parturition, and thereafter, on the duration of the post-partum anoestrous period was mediated through differences in gonadotrophin receptor concentrations in the ovarian follicles. Two groups of cows were fed to achieve body condition scores of > or = 2.75 (H; n = 14) or < or = 2.00 (L; n = 15) at parturition (this had led to differences in the duration of post-partum anoestrus in previous experiments) and then fed to maintain liveweight and condition until ovariectomy at nine weeks post partum. There was no effect of body condition on the mean (+/- s.e.) number of large (> or = 8 mm diameter) follicles per cow (3.0 +/- 0.27) but a greater proportion of the follicles of H cows, compared with L cows, was oestrogenic (secreting > 250 pg oestradiol h-1 in culture) (0.75 v. 0.5; chi 2 = 3.40; P = 0.06). Mean concentrations (pg hormone bound per mg protein) of follicle stimulating hormone (FSH) receptors in both granulosa (H, 157.3; L, 136.6; standard error of difference (s.e.d.) = 27.2) and thecal tissue (H, 4.14; L, 4.35; s.e.d. = 1.66) were similar for H and L cows. There was no difference associated with treatment in luteinizing hormone (LH) receptor concentrations in either granulosa (H, 40.3; L, 37.2; s.e.d. = 6.67) or thecal tissue (H, 48.9; L, 48.0; s.e.d. = 6.03). The concentration of FSH receptors in granulosa tissue was lower in non-oestrogenic follicles than in oestrogenic follicles (80.0 v. 188.1; s.e.d. = 40.4; P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen, Scotland.
authors.forename: S M
authors.initials: SM
authors.lastname: Rhind
authors.forename: T A
authors.initials: TA
authors.lastname: Bramley
authors.forename: I A
authors.initials: IA
authors.lastname: Wright
authors.forename: S R
authors.initials: SR
authors.lastname: McMillen
mesh_terms: D000818:Animals; D001835:Body Weight; D002417:Cattle / Q000502:physiology*; D004958:Estradiol / Q000032:analysis; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood / Q000378:metabolism; D015571:Follicular Fluid / Q000737:chemistry; D006107:Granulosa Cells / Q000378:metabolism; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism; D009752:Nutritional Status / Q000502:physiology; D006080:Ovarian Follicle / Q000378:metabolism*; D049590:Postpartum Period / Q000378:metabolism*; D011897:Random Allocation; D011962:Receptors, FSH / Q000096:biosynthesis*; D011974:Receptors, LH / Q000096:biosynthesis*; D013739:Testosterone / Q000032:analysis; D013799:Theca Cells / Q000378:metabolism
chemical_list: D011962:Receptors, FSH; D011974:Receptors, LH; D013739:Testosterone; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone