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B R Leeuwenberg, N L Hudson, L G Moore, P R Hurst, and K P McNatty

Abstract

IGF-I was measured by RIA in plasma samples collected 8-hourly for 24 days which included two consecutive preovulatory surges of LH. In a separate study, ovarian venous blood was collected from animals undergoing ovariectomy on day 10 of the oestrous cycle, or 36 h later after being treated with prostaglandin with or without steroid-free bovine follicular fluid. Jugular venous blood samples were collected before, during and after surgery. Follicles were dissected from ovaries of these animals and sorted into categories of small, intermediate and large, non-atretic or atretic, and the follicular fluid was pooled and assayed for IGF-I. From another population of ovaries recovered from the slaughterhouse, granulosa, theca and corpora lutea were isolated, homogenized and assayed for IGF-I. Finally ovarian corpora lutea and granulosa cells were each incubated with tritiated amino acids overnight at 37 °C. Thereafter the tissues and media were sonicated, IGF-I extracted from the supernatant and tritiated IGF-I precipitated using a specific IGF-I antibody.

The absence of any significant change in peripheral IGF-I concentrations following ovariectomy and the finding that the ovarian venous IGF-I concentrations (161 ± 10 μg/l) were not significantly different from levels seen in peripheral blood (157 ± 10 μg/l) indicated that the ovary is not a net exporter of IGF-I. However, the ovary does synthesize IGF-I, as evidenced by granulosa and luteal synthesis, but probably not in quantities in excess of that utilized by ovarian tissues per se. Although the plasma IGF-I levels increased around the second preovulatory LH surge, the results overall indicated that the IGF-I concentrations in plasma are not strictly related to any major ovarian event during the oestrous cycle in the sheep. This view is based on the findings that the concentration of IGF-I in follicular fluid was not related to follicular health but correlated with those in peripheral plasma and that the ovarian venous concentrations did not vary between left and right ovaries irrespective of whether the ovaries contained a corpus luteum, dominant follicle or neither. Collectively, these results are consistent with the notion that IGF-I of ovarian origin fulfils an autocrine/paracrine function and does not have an endocrine role. Moreover, the results show that the concentrations of IGF-I in follicular fluid reflect those in peripheral plasma.

Journal of Endocrinology (1996) 148, 281–289

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Ashley Grossman

Sixty years ago, in 1955, Geoffrey Harris published his seminal work on the relationship between the hypothalamus and pituitary. Originally based on his realisation that seasonal breeding necessitates some sort of central control of gonadal function

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Nicoleta C Olarescu, Darlene E Berryman, Lara A Householder, Ellen R Lubbers, Edward O List, Fabian Benencia, John J Kopchick, and Jens Bollerslev

O for 6 s as previously described ( Houlihan et al . 2012 ). The SVF was spun down again by centrifugation, and the pellets were resuspended in fresh PBS. Fluorescence-activated cell sorting After being incubated with specific antibodies, SVF

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Marumi Osuna, Yokiko Sonobe, Eisuke Itakura, Sukumar Devnath, Takako Kato, Yukio Kato, and Kinji Inoue

detection and observation of living FS cells with cell-specific expression of GFP ( Itakura et al . 2007 ). Anterior lobes of pituitary glands were chopped and digested with collagenase, and the suspended cells were sorted with a cell sorter (EPICS Elite

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Urs Lichtenauer, Igor Shapiro, Simone Sackmann, Jacques Drouin, Jürgen Scheele, Matthias Maneck, Christoph Klein, and Felix Beuschlein

, and 10 μl/ml Pen/Strep, all from Gibco) and sequentially filtered through a 100 and 70 μm nylon mesh respectively. Cells were counted using a Neubauer counting chamber and further processed. Hoechst staining and FACS sorting Murine single

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T Balla

undergo ligand-induced endocytosis mostly (but not exclusively) by a clathrin-mediated internalization process that shares many of the characteristics of the endocytosis and recycling of nutrient receptors ( Brown & Goldstein 1979 ). The sorting of the

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Antonis Voutetakis, Ioannis Bossis, Marc R Kok, Weitian Zhang, Jianghua Wang, Ana P Cotrim, Changyu Zheng, John A Chiorini, Lynnette K Nieman, and Bruce J Baum

peptide will be physiologically wasted by being secreted via saliva into the gastrointestinal tract. There are a number of reports suggesting that RSP sorting is signal dependent (i.e. amino acid sequence dependent; e.g. Kelly 1985 , Gerdes

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Sophie Fouchécourt, Murielle Godet, Odile Sabido, and Philippe Durand

the culture medium during the last 20 h. On day 2, the cells were detached from the culture dishes by trypsination. Cell viability was assessed by Trypan Blue exclusion. Sertoli (vimentin positive) and germ cells (vimentin negative) were sorted by flow

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Cimi Ilmiawati, Kotaro Horiguchi, Ken Fujiwara, and Takashi Yashiro

pituitary cells of S100b-GFP male rats were dispersed as described in a previous report ( Horiguchi et al . 2008 ). The dispersed cells were then sorted by a MoFlo XDP (Beckman Coulter, Inc., Fullerton, CA, USA) into GFP-positive (GFP+) and GFP

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Kotaro Horiguchi, Ken Fujiwara, Cimi Ilmiawati, Motoshi Kikuchi, Takehiro Tsukada, Tom Kouki, and Takashi Yashiro

sorter (MoFlo XDP: Beckman Coulter, Inc., Fullerton, CA, USA). GFP-positive cells were plated onto 8-well glass chamber slides (1 cm 2 /well; Nalge Nunc International, Rochester, NY, USA), with or without a coating of 10 μg/cm 2 of laminin (Millipore