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J E Kinde - One of the best experts on this subject based on the ideXlab platform.
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changes in ovarian function and gonadotropin secretion preceding the onset of nutritionally induced anestrus in bos indicus heifers
Biology of Reproduction, 1996Co-Authors: F M Rhodes, K W Entwistle, J E KindeAbstract:: The aim of this study was to monitor endocrine and ovarian changes immediately preceding the onset of nutritionally induced anestrus. Daily blood samples were obtained from 14 postpubertal heifers for one estrous Cycle (initial estrous Cycle). Subsequently, heifers designated "restricted" were given a limited diet (n = 9), and daily blood samples were obtained for approximately 21 days preceding onset of anestrus (Anovulatory Cycle). Controls were allowed ad libitum dietary intake (n = 5), and daily blood samples were collected for a complete estrous Cycle during a time period that coincided with that preceding onset of anestrus in restricted heifers. Plasma samples were assayed for LH, FSH, progesterone, and estradiol-17 beta. The ovaries of all heifers were examined daily using transrectal ultrasonography from the initial until the final or Anovulatory estrous Cycles to determine changes in growth of follicles and corpora lutea. Anestrus was defined as failure of ovulation of the dominant follicle following luteolysis. When Anovulatory and initial estrous Cycles in restricted heifers were compared, mean concentrations of LH were lower (p 0.10). In controls, no differences were found between estrous Cycles for any of these variables. It is concluded that failure of ovulation, following reduced dietary intake, resulted from insufficient circulating LH to stimulate maturation of the ovulatory follicle.
F M Rhodes - One of the best experts on this subject based on the ideXlab platform.
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Changes in Ovarian Function and Gonadotropin Secretion Preceding the Onset of Nutritionally Induced Anestrus in Bos indicus Heifers'
2016Co-Authors: F M Rhodes, K W Entwistle, E. KinderAbstract:The aim of this study was to monitor endocrine and ovarian changes immediately preceding the onset of nutritionally in-duced anestrus. Daily blood samples were obtained from 14 postpubertal heifers for one estrous Cycle (initial estrous Cycle). Subsequently, heifers designated "restricted " were given a lim-ited diet (n = 9), and daily blood samples were obtained for approximately 21 days preceding onset of anestrus (Anovulatory Cycle). Controls were allowed ad libitum dietary intake (n = 5), and daily blood samples were collected for a complete estrous Cycle during a time period that coincided with that preceding onset of anestrus in restricted heifers. Plasma samples were as-sayed for LH, FSH, progesterone, and estradiol-178. The ovaries of all heifers were examined daily using transrectal ultrasonog-raphy from the initial until the final or Anovulatory estrous cy-cles to determine changes in growth of follicles and corpora lutea. Anestrus was defined as failure of ovulation of the dom-inant follicle following luteolysis. When Anovulatory and initial estrous Cycles in restricted heifers were compared, mean con-centrations of LH were lower (p < 0.01), and diameters of dom-inant follicles were smaller (p < 0.01); mean concentrations of estradiol-173 were also lower in the three days following luteo-lysis (p = 0.06), but concentrations of FSH appeared to be high-er (p = 0.003); maximum diameters of corpora lutea were small-er (p < 0.001), but duration of luteal phases and concentrations of progesterone preceding luteolysis were similar (p> 0.10). In controls, no differences were found between estrous Cycles for any of these variables. It is concluded that failure of ovulation, following reduced dietary intake, resulted from insufficient cir-culating LH to stimulate maturation of the ovulatory follicle
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changes in ovarian function and gonadotropin secretion preceding the onset of nutritionally induced anestrus in bos indicus heifers
Biology of Reproduction, 1996Co-Authors: F M Rhodes, K W Entwistle, J E KindeAbstract:: The aim of this study was to monitor endocrine and ovarian changes immediately preceding the onset of nutritionally induced anestrus. Daily blood samples were obtained from 14 postpubertal heifers for one estrous Cycle (initial estrous Cycle). Subsequently, heifers designated "restricted" were given a limited diet (n = 9), and daily blood samples were obtained for approximately 21 days preceding onset of anestrus (Anovulatory Cycle). Controls were allowed ad libitum dietary intake (n = 5), and daily blood samples were collected for a complete estrous Cycle during a time period that coincided with that preceding onset of anestrus in restricted heifers. Plasma samples were assayed for LH, FSH, progesterone, and estradiol-17 beta. The ovaries of all heifers were examined daily using transrectal ultrasonography from the initial until the final or Anovulatory estrous Cycles to determine changes in growth of follicles and corpora lutea. Anestrus was defined as failure of ovulation of the dominant follicle following luteolysis. When Anovulatory and initial estrous Cycles in restricted heifers were compared, mean concentrations of LH were lower (p 0.10). In controls, no differences were found between estrous Cycles for any of these variables. It is concluded that failure of ovulation, following reduced dietary intake, resulted from insufficient circulating LH to stimulate maturation of the ovulatory follicle.
H L Hambridge - One of the best experts on this subject based on the ideXlab platform.
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ORIGINAL ARTICLE Reproductive epidemiology The influence of sporadic anovulation on hormone levels in ovulatory Cycles
2016Co-Authors: H L Hambridge, Jean Wactawski-wende, Donald R Mattison, Anna Z Pollack, Michael S Bloom, Pauline Mendola, K L Lynch, S. L. Mumford, Enrique F SchistermanAbstract:study question: Do ovulatory hormone profiles among healthy premenopausal women differ between women with and without sporadic anovulation? summary answer: Women with one Anovulatory Cycle tended to have lower estradiol, progesterone and LH peak levels during their ovulatory Cycle. what is known already: Anovulation occurs sporadically in healthy premenopausal women, but the influence of hormones in a preceding Cycle and the impact on a subsequent Cycle’s hormone levels is unknown. study design, size, duration: The BioCycle Study was a prospective cohort including 250 healthy regularly menstruating women, 18–44 years of age, from Western New York with no history of menstrual or ovulation disorders. The women were followed with up to eight study visits per Cycle for two Cycles, most of which were consecutive. participants/materials, setting and methods: All study visits were timed to menstrual Cycle phase using fertilit
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the influence of sporadic anovulation on hormone levels in ovulatory Cycles
Human Reproduction, 2013Co-Authors: Sunni L Mumford, H L Hambridge, Donald R Mattison, Aijun Ye, Anna Z Pollack, Michael S Bloom, Pauline Mendola, K L Lynch, Jean WactawskiwendeAbstract:study design, size, duration: The BioCycle Study was a prospective cohort including 250 healthy regularly menstruating women, 18– 44 years of age, from Western New York with no history of menstrual or ovulation disorders. The women were followed with up to eight study visits per Cycle for two Cycles, most of which were consecutive. participants/materials, setting and methods: All study visits were timed to menstrual Cycle phase using fertility monitors and located at the University at Buffalo women’s health research center from 2005 to 2007. The main outcomes measured were estradiol, progesterone, LH and follicle-stimulating hormone levels in serum at up to 16 visits over two Cycles. Anovulation was defined as peak serum progesterone concentrations ≤5 ng/ml and no serum LH peak detected during the mid- or late-luteal phase visit. main results and the role of chance:Reproductive hormone concentrations were lower during Anovulatory Cycles, but significant reductions were also observed in estradiol (225%, P ¼ 0.003) and progesterone (222%, P ¼ 0.001) during the ovulatory Cycles of women with one Anovulatory Cycle compared with women with two ovulatory Cycles. LH peak concentrations were decreased in the ovulatory Cycle of women with an Anovulatory Cycle (significant amplitude effect, P ¼ 0.004; geometric mean levels 38% lower, P , 0.05). limitations, reasons for caution: Follow-up was limited to two menstrual Cycles, and no ultrasound assessment of ovulation was available. Data were missing for a total of 168 of a possible 4072 Cycle visits (4.1%), though all women had at least five visits per Cycle (94% had seven or more per Cycle). wider implications of the findings: These results suggest a possible underlying cause of anovulation, such as a longer-term subclinical follicular, ovarian or hypothalamic/pituitary dysfunction, even among healthy, regularly menstruating women.
K W Entwistle - One of the best experts on this subject based on the ideXlab platform.
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Changes in Ovarian Function and Gonadotropin Secretion Preceding the Onset of Nutritionally Induced Anestrus in Bos indicus Heifers'
2016Co-Authors: F M Rhodes, K W Entwistle, E. KinderAbstract:The aim of this study was to monitor endocrine and ovarian changes immediately preceding the onset of nutritionally in-duced anestrus. Daily blood samples were obtained from 14 postpubertal heifers for one estrous Cycle (initial estrous Cycle). Subsequently, heifers designated "restricted " were given a lim-ited diet (n = 9), and daily blood samples were obtained for approximately 21 days preceding onset of anestrus (Anovulatory Cycle). Controls were allowed ad libitum dietary intake (n = 5), and daily blood samples were collected for a complete estrous Cycle during a time period that coincided with that preceding onset of anestrus in restricted heifers. Plasma samples were as-sayed for LH, FSH, progesterone, and estradiol-178. The ovaries of all heifers were examined daily using transrectal ultrasonog-raphy from the initial until the final or Anovulatory estrous cy-cles to determine changes in growth of follicles and corpora lutea. Anestrus was defined as failure of ovulation of the dom-inant follicle following luteolysis. When Anovulatory and initial estrous Cycles in restricted heifers were compared, mean con-centrations of LH were lower (p < 0.01), and diameters of dom-inant follicles were smaller (p < 0.01); mean concentrations of estradiol-173 were also lower in the three days following luteo-lysis (p = 0.06), but concentrations of FSH appeared to be high-er (p = 0.003); maximum diameters of corpora lutea were small-er (p < 0.001), but duration of luteal phases and concentrations of progesterone preceding luteolysis were similar (p> 0.10). In controls, no differences were found between estrous Cycles for any of these variables. It is concluded that failure of ovulation, following reduced dietary intake, resulted from insufficient cir-culating LH to stimulate maturation of the ovulatory follicle
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changes in ovarian function and gonadotropin secretion preceding the onset of nutritionally induced anestrus in bos indicus heifers
Biology of Reproduction, 1996Co-Authors: F M Rhodes, K W Entwistle, J E KindeAbstract:: The aim of this study was to monitor endocrine and ovarian changes immediately preceding the onset of nutritionally induced anestrus. Daily blood samples were obtained from 14 postpubertal heifers for one estrous Cycle (initial estrous Cycle). Subsequently, heifers designated "restricted" were given a limited diet (n = 9), and daily blood samples were obtained for approximately 21 days preceding onset of anestrus (Anovulatory Cycle). Controls were allowed ad libitum dietary intake (n = 5), and daily blood samples were collected for a complete estrous Cycle during a time period that coincided with that preceding onset of anestrus in restricted heifers. Plasma samples were assayed for LH, FSH, progesterone, and estradiol-17 beta. The ovaries of all heifers were examined daily using transrectal ultrasonography from the initial until the final or Anovulatory estrous Cycles to determine changes in growth of follicles and corpora lutea. Anestrus was defined as failure of ovulation of the dominant follicle following luteolysis. When Anovulatory and initial estrous Cycles in restricted heifers were compared, mean concentrations of LH were lower (p 0.10). In controls, no differences were found between estrous Cycles for any of these variables. It is concluded that failure of ovulation, following reduced dietary intake, resulted from insufficient circulating LH to stimulate maturation of the ovulatory follicle.
Enrique F Schisterman - One of the best experts on this subject based on the ideXlab platform.
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ORIGINAL ARTICLE Reproductive epidemiology The influence of sporadic anovulation on hormone levels in ovulatory Cycles
2016Co-Authors: H L Hambridge, Jean Wactawski-wende, Donald R Mattison, Anna Z Pollack, Michael S Bloom, Pauline Mendola, K L Lynch, S. L. Mumford, Enrique F SchistermanAbstract:study question: Do ovulatory hormone profiles among healthy premenopausal women differ between women with and without sporadic anovulation? summary answer: Women with one Anovulatory Cycle tended to have lower estradiol, progesterone and LH peak levels during their ovulatory Cycle. what is known already: Anovulation occurs sporadically in healthy premenopausal women, but the influence of hormones in a preceding Cycle and the impact on a subsequent Cycle’s hormone levels is unknown. study design, size, duration: The BioCycle Study was a prospective cohort including 250 healthy regularly menstruating women, 18–44 years of age, from Western New York with no history of menstrual or ovulation disorders. The women were followed with up to eight study visits per Cycle for two Cycles, most of which were consecutive. participants/materials, setting and methods: All study visits were timed to menstrual Cycle phase using fertilit
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Effect of daily fiber intake on reproductive function: The BioCycle Study
American Journal of Clinical Nutrition, 2009Co-Authors: Audrey J Gaskins, Edwina Yeung, Cuilin Zhang, Penelope P Howards, Sunni L Mumford, Kathleen M Hovey, Brian W Whitcomb, Neil J Perkins, Jean Wactawski-wende, Enrique F SchistermanAbstract:BACKGROUND: High-fiber diets have been associated with decreased breast cancer risk, likely mediated by the effect of fiber on lowering circulating estrogen concentrations. The influence of fiber on aspects of reproduction, which include ovulation, has not been well studied in premenopausal women.\n\nOBJECTIVE: The objective was to determine if fiber consumption is associated with hormone concentrations and incident anovulation in healthy, regularly menstruating women.\n\nDESIGN: The BioCycle Study was a prospective cohort study conducted from 2004 to 2006 that followed 250 women aged 18-44 y for 2 Cycles. Dietary fiber consumption was assessed < or =4 times/Cycle by using 24-h recall. Outcomes included concentrations of estradiol, progesterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH), which were measured < or =8 times/Cycle, and incident anovulation.\n\nRESULTS: Dietary fiber consumption was inversely associated with hormone concentrations (estradiol, progesterone, LH, and FSH; P < 0.05) and positively associated with the risk of anovulation (P = 0.003) by using random-effects models with adjustment for total calories, age, race, and vitamin E intake. Each 5-g/d increase in total fiber intake was associated with a 1.78-fold increased risk (95% CI: 1.11, 2.84) of an Anovulatory Cycle. The adjusted odds ratio of 5 g fruit fiber/d was 3.05 (95% CI: 1.07, 8.71).\n\nCONCLUSIONS: These findings suggest that a diet high in fiber is significantly associated with decreased hormone concentrations and a higher probability of anovulation. Further study of the effect of fiber on reproductive health and of the effect of these intakes in reproductive-aged women is warranted.