Validation of different measures of insulin sensitivity of glucose metabolism in dairy cows using the hyperinsulinemic euglycemic clamp test as the gold standard
The aim of the present research was to compare different measures of insulin sensitivity in dairy cows at the end of the dry period. To do so, ten clinically healthy dairy cows with a varying body condition score were selected. By performing hyperinsulinemic euglycemic clamp (HEC) tests, we previously demonstrated a negative association between the insulin sensitivity and insulin responsiveness of glucose metabolism and the body condition score of these animals. In the same animals, other measures of insulin sensitivity were determined and the correlation with the HEC test, which is considered as the gold standard, was cal...
Source: Domestic Animal Endocrinology - June 29, 2016 Category: Endocrinology Authors: J. De Koster, M. Hostens, K. Hermans, W. Van den Broeck, G. Opsomer Source Type: research
Is progesterone the key regulatory factor behind ovulation rate in sheep?
Ovarian antral follicles in the ewe grow in an orderly succession, producing 3 to 4 waves per estrous cycle. In prolific sheep, some large antral follicles from the second-to-last wave of the estrous cycle are added to the ovulatory follicles emerging just before estrus to give a higher ovulation rate; it is feasible that regression of these follicles is prevented by an increase in serum concentrations of FSH and/or LH pulsatility at proestrus. Prolific sheep tend to have a shorter luteal phase than nonprolific ewes, and there is a great deal of evidence that luteal progesterone (P4), in addition to regulating LH release, ...
Source: Domestic Animal Endocrinology - June 27, 2016 Category: Endocrinology Authors: P.M. Bartlewski, J. Sohal, V. Paravinja, T. Baby, M.E.F. Oliveira, M. Murawski, T. Schwarz, D.A. Zieba, D.H. Keisler Source Type: research
WITHDRAWN: Is progesterone the key regulatory factor behind ovulation rate in sheep?
This article has been withdrawn at the request of the author(s) and/or editor. The Publisher apologizes for any inconvenience this may cause.The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy. (Source: Domestic Animal Endocrinology)
Source: Domestic Animal Endocrinology - June 27, 2016 Category: Endocrinology Authors: P.M. Bartlewski, J. Sohal, V. Paravinja, T. Baby, M.E.F. Oliveira, M. Murawski, T. Schwarz, D.A. Zieba, D.H. Keisler Source Type: research
Is progesterone the key regulatory factor behind ovulation rate in sheep?
Ovarian antral follicles in the ewe grow in an orderly succession, producing 3-4 waves per estrous cycle. In prolific sheep, some large antral follicles from the second-to-last wave of the estrous cycle are added to the ovulatory follicles emerging just before estrus to give a higher ovulation rate; it is feasible that regression of these follicles is prevented by an increase in serum concentrations of follicle-stimulating hormone (FSH) and/or luteinizing hormone (LH) pulsatility at pro-estrus. Prolific sheep tend to have a shorter luteal phase than non-prolific ewes and there is a great deal of evidence that luteal proges...
Source: Domestic Animal Endocrinology - June 27, 2016 Category: Endocrinology Authors: P.M. Bartlewski, J. Sohal, V. Paravinja, T. Baby, M.E.F. Oliveira, M. Murawski, T. Schwarz, D.A. Zieba, D.H. Keisler Source Type: research
Downregulation of LH and FSH receptors after hCG and eCG treatments in the porcine oviduct
The influence of induction of ovulation and superovulation with eCG and hCG on LH and FSH receptor levels in porcine oviducts on day 3 postcoitum was studied. In experiment I, gilts were assigned into cyclic (control; n = 5) and inseminated (n = 5) groups. In experiment II, there were 3 groups of animals: inseminated (n = 5), induced ovulation/inseminated (750 IU eCG, 500 IU hCG; n = 5) and superovulated/inseminated (1500 IU eCG, 1000 IU hCG; n = 5) gilts. Oviduct tissu es were collected 3 d after insemination or PBS infusion. (Source: Domestic Animal Endocrinology)
Source: Domestic Animal Endocrinology - June 14, 2016 Category: Endocrinology Authors: I. Ma łysz-Cymborska, A. Andronowska Tags: Short Communication Source Type: research
Downregulation of LH and FSH receptors after hCG and eCG treatments in the porcine oviduct
The influence of induction of ovulation and superovulation with eCG and hCG on LH and FSH receptor levels in porcine oviducts on day 3 postcoitum was studied. In experiment I, gilts were assigned into cyclic (control; n = 5) and inseminated (n = 5) groups. In experiment II, there were 3 groups of animals: inseminated (n = 5), induced ovulation/inseminated (750 IU eCG, 500 IU hCG; n = 5) and superovulated/inseminated (1500 IU eCG, 1000 IU hCG; n = 5) gilts. Oviduct tissues were collected 3 d after insemination or PBS infusion. (Source: Domestic Animal Endocrinology)
Source: Domestic Animal Endocrinology - June 14, 2016 Category: Endocrinology Authors: I. Małysz-Cymborska, A. Andronowska Tags: Short Communication Source Type: research
Downregulation of luteinizing hormone and follicle-stimulating hormone receptors after hCG and eCG treatments in the porcine oviduct
The influence of induction of ovulation and superovulation with eCG and hCG on LH and FSH receptor levels in porcine oviducts on day 3 post coitum was studied. In experiment I, gilts were assigned into cyclic (control; n=5) and inseminated (control; n=5) groups. In experiment II, there were three groups of animals: inseminated (n=5), induced ovulation/inseminated (750 IU eCG, 500 IU hCG; n=5) and superovulated/inseminated (1500 IU eCG, 1000 IU hCG; n=5) gilts. Oviduct tissues were collected 3 d after insemination or PBS infusion. (Source: Domestic Animal Endocrinology)
Source: Domestic Animal Endocrinology - June 14, 2016 Category: Endocrinology Authors: I. Małysz-Cymborska, A. Andronowska Source Type: research
The theory of follicle selection in cattle
Selection of the dominant follicle (DF) during a follicular wave is manifested by diameter deviation or continued growth rate of the largest follicle (F1) and decreased growth rate of the next largest follicle (F2) when F1 reaches about 8.5 mm in cattle. The process of deviation in the future DF begins about 12 h before diameter deviation and involves an F1 increase in granulosa LH receptors and estradiol and maintenance of intrafollicular free insulin-like growth factor 1 (IGF1). Thereby, only F1 is developmentally prepared to use the declining FSH in the wave-stimulating FSH surge and to respond to a transient increas...
Source: Domestic Animal Endocrinology - June 12, 2016 Category: Endocrinology Authors: O.J. Ginther Tags: Review Source Type: research
The theory of follicle selection in cattle
Selection of the dominant follicle (DF) during a follicular wave is manifested by diameter deviation or continued growth rate of the largest follicle (F1) and decreased growth rate of the next largest follicle (F2) when F1 reaches about 8.5 mm in cattle. The process of deviation in the future DF begins about 12 h before diameter deviation and involves an F1 increase in granulosa LH receptors and estradiol and maintenance of intrafollicular free insulin-like growth factor 1 (IGF1). Thereby, only F1 is developmentally prepared to utilize the declining FSH in the wave-stimulating FSH surge and to respond to a transient increa...
Source: Domestic Animal Endocrinology - June 12, 2016 Category: Endocrinology Authors: O.J. Ginther Source Type: research
Changes in ovarian function associated with circulating concentrations of estradiol before a GnRH-induced ovulation in beef cows
These studies were conducted to evaluate causes for differences in circulating concentrations of estradiol before a GnRH-induced ovulation. Beef cows were synchronized by an injection of GnRH on day −7 and an injection of PGF2α on day 0. In experiment 1, blood samples were collected every 3 h from PGF2α on day 0 to hour 33 after PGF2α and at slaughter (hour 36 to 42; n = 10). Cows were assigned to treatment group based on circulating concentrations of estradiol (E2): HighE2 vs LowE2. At s laughter, follicular fluid (FF) and granulosa cells were collected from the dominant follicle. (Source: Domestic Animal Endocrinology)
Source: Domestic Animal Endocrinology - June 7, 2016 Category: Endocrinology Authors: E.L. Larimore, O.L. Amundson, G.A. Bridges, A.K. McNeel, R.A. Cushman, G.A. Perry Source Type: research
Changes in ovarian function associated with circulating concentrations of estradiol before a GnRH-induced ovulation in beef cows
These studies were conducted to evaluate causes for differences in circulating concentrations of estradiol before a GnRH-induced ovulation. Beef cows were synchronized by an injection of GnRH on day −7 and an injection of PGF2α on day 0. In experiment 1, blood samples were collected every 3 h from PGF2α on day 0 to hour 33 after PGF2α and at slaughter (hour 36 to 42; n = 10). Cows were assigned to treatment group based on circulating concentrations of estradiol (E2): HighE2 vs LowE2. At slaughter, follicular fluid (FF) and granulosa cells were collected from the dominant follicle. (Source: Domestic Animal Endocrinology)
Source: Domestic Animal Endocrinology - June 7, 2016 Category: Endocrinology Authors: E.L. Larimore, O.L. Amundson, G.A. Bridges, A.K. McNeel, R.A. Cushman, G.A. Perry Source Type: research
Changes in ovarian function associated with circulating concentrations of estradiol prior to a GnRH-induced ovulation in beef cows
These studies were conducted to evaluate causes for differences in circulating concentrations of estradiol prior to a GnRH-induced ovulation. Beef cows were synchronized by an injection of GnRH on day -7 and an injection of PGF₂α on d 0. In Experiment 1, blood samples were collected every 3 h from PGF₂α on day 0 to hour 33 after PGF₂α and at slaughter (hour 36 to 42; n=10). Cows were assigned to treatment group based on circulating concentrations of E2: HighE2 vs LowE2. At slaughter, follicular fluid (FF) and granulosa cells were collected from the dominant follicle (DF). (Source: Domestic Animal Endocrinology)
Source: Domestic Animal Endocrinology - June 7, 2016 Category: Endocrinology Authors: E.L. Larimore, O.L. Amundson, G.A. Bridges, A.K. McNeel, R.A. Cushman, G.A. Perry Source Type: research
Dosing obese cats based on body weight spuriously affects some measures of glucose tolerance
The primary objective was to investigate whether dosing glucose by body weight results in spurious effects on measures of glucose tolerance in obese cats because volume of distribution does not increase linearly with body weight. Healthy research cats (n = 16; 6 castrated males, 10 spayed females) were used. A retrospective study was performed using glucose concentration data from glucose tolerance and insulin sensitivity tests before and after cats were fed ad libitum for 9 to 12 mo to promote weight gain. (Source: Domestic Animal Endocrinology)
Source: Domestic Animal Endocrinology - May 26, 2016 Category: Endocrinology Authors: M.K. Reeve-Johnson, J.S. Rand, S.T. Anderson, D.J. Appleton, J.M. Morton, D. Vankan Source Type: research
Diagnosis of prediabetes in cats: glucose concentration cut points for impaired fasting glucose and impaired glucose tolerance
The objective of the study was to establish methodology and cut points for fasting and 2-h blood glucose concentrations in healthy client-owned senior cats ( ≥8 yr) using ear/paw samples and a portable glucose meter calibrated for feline blood. Of the 78 cats, 27 were ideal (body condition score [BCS] 4 or 5 of 9), 31 overweight (BCS 6 or 7), and 20 obese (BCS 8 or 9); 19 were Burmese and 59 non-Burmese. (Source: Domestic Animal Endocrinology)
Source: Domestic Animal Endocrinology - May 26, 2016 Category: Endocrinology Authors: M.K. Reeve-Johnson, J.S. Rand, D. Vankan, S.T. Anderson, R. Marshall, J.M. Morton Source Type: research
Temporal relationships between minor, preovulatory, or periovulatory FSH surges and the emergence and development of 2-mm follicles of wave 1 in Bos taurus heifers
The number and day of emergence (first detection) of 2-mm follicles and the number and day when the 2-mm follicles reached 3-, 4-, 5-, and 6-mm during wave 1 were determined every 0.5 d (n = 9 heifers). Emergence of the follicles at each of the indicated diameters was normalized to the beginning and ending nadir and the peak of each of a minor FSH surge, the preovulatory surge, and the periovulatory surge. Relative to the day of ovulation (day 0), the minor FSH surge, preovulat ory surge, and periovulatory surge encompassed (nadir to nadir) days −7.0 to −2.5 (peak, day −4.0), days −2.5 to −0.5 (peak, day −1.0...
Source: Domestic Animal Endocrinology - May 26, 2016 Category: Endocrinology Authors: J.M. Baldrighi, M.A.R. Siddiqui, O.J. Ginther Tags: Short Communication Source Type: research
