Experimental Analysis of Hormone Actions on the Hypothalamus, Anterior Pituitary, and Ovary

Feder, Harvey H.

doi:10.1007/978-1-4684-3875-8_9

Cited by 7 publications

(2 citation statements)

References 196 publications

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“…Beal et al (1978) and Killen et al (1989) found that undemutrition in cycling and prepartum heifers, respectively, enhanced GnRH-induced LH release; however, Entwistle and Oga (1977) found no effect of undemutrition on LH release in response to GnRH in postpartum cows. Pituitary gonadotropins and ovarian steroids interact to control the bovine estrous cycle and initiate postpartum estrous cyclicity (Wettemarm, 1980;Feder, 1981). Although serum LH concentration during estrus differs between Hereford and Brahman heifers (Randel, 1976), the relationship between biological type and secretion of LH has not been clearly defined (Griffin and Randel, 1977).…”

Section: Introductionmentioning

confidence: 99%

Effects of Nutritional Level and Biological Type on Gonadotropin-Releasing Hormone-Induced Luteinizing Hormone Release and Plasma Progesterone, Estrone and Estradiol Concentrations in Pre- and Post-Partum Beef Heifers

Killen

Forrest²,

Byers³

et al. 1989

Journal of Animal Science

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Forty-six beef heifers (16 to 23 mo) of two biological types (small = Red Poll-sired, large = Charolais-sired) were individually fed from d 90 of gestation through parturition to evaluate the effects of nutritional restriction on plasma LH and steroid hormone concentrations. Heifers were allotted to one of two nutritional treatments to achieve a BW reduction (loss, fed at 1% of BW/d) or to maintain initial BW (maintenance, fed 1.5% of BW/d) to parturition. Gonadotropin-releasing hormone (100 micrograms) was injected i.m. three times during gestation (d 130; d 200; d 270) and twice after parturition (d 1 to 14; d 23 to 36). Blood samples were collected at 20-min intervals after GnRH for 4 h. Maternal BW change from d 90 to parturition differed (P less than .01) between loss and maintenance heifers. Mean plasma progesterone concentrations were greater (P less than .05) at d 130 and 270 of gestation in small than in large heifers and were greater (P less than .01) at d 23 to 36 postpartum in maintenance than in loss heifers. Mean concentrations of estrone and estradiol were greater (P less than .05) in large than in small heifers at d 200 of gestation. Mean plasma LH concentrations following GnRH injection were greater (P less than .01) in loss than in maintenance heifers at 200 and 270 d of gestation. Metabolizable and retained energy were related inversely to LH release during mid and late gestation.(ABSTRACT TRUNCATED AT 250 WORDS)

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Section: Introductionmentioning

confidence: 99%

Effects of Nutritional Level and Biological Type on Gonadotropin-Releasing Hormone-Induced Luteinizing Hormone Release and Plasma Progesterone, Estrone and Estradiol Concentrations in Pre- and Post-Partum Beef Heifers

Killen

Forrest²,

Byers³

et al. 1989

Journal of Animal Science

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“…The requirements for particular goal objects change depending on the stage of the life cycle and contingencies imposed by the external environment.In female rats, changes in reproductive state dramatically alter choice of goal objects. Proceptivity toward males and the appropriate display of maternal behavior toward young both occur at clearly delineated phases of the reproductive cycle (e.g., see Feder, 1981;Numan, 1994). Overall food intake and nutrient choice have also been shown to vary across reproductive states: salt and carbohydrate intake change with estrus cycle stage (Danielsen & Buggy, 1980; Wurtman & Baum, 1980); pregnant female rats increase their intake of sodium and protein, and lactating females increase their intake of protein, fat, calcium, and sodium (Cohen…”

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Administration of ovarian steroid hormones does not change the reward effectiveness of lateral hypothalamic stimulation in ovariectomized rats

1996

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The effect of two schedules of steroid honnone administration on the reward effectiveness of lateral hypothalamic stimulation was examined in ovariectomized Long-Evans female rats. In Experiment 1, estrogen and progesterone were administered on a 4-day schedule so as to mimic the honnonal profile of the estrous cycle; in Experiment 2, silastic implants of progesterone and estrogen were used to induce steroid honnone levels similar to those observed in mid-and late pregnancy. In both experiments, hormone administration was sufficient to induce characteristic behaviors: lordosis in Experiment 1 and a change in sucrose preference and body weight in Experiment 2. In contrast, honnone administration did not change the reward effectiveness of the electrical stimulation in either Experiment 1 or Experiment 2.In order to maintain homeostasis and satisfy reproductive imperatives, animals must select among a variety of goal objects available in the environment and then show the appropriate behaviors toward those goal objects. The requirements for particular goal objects change depending on the stage of the life cycle and contingencies imposed by the external environment.In female rats, changes in reproductive state dramatically alter choice of goal objects. Proceptivity toward males and the appropriate display of maternal behavior toward young both occur at clearly delineated phases of the reproductive cycle (e.g., see Feder, 1981;Numan, 1994). Overall food intake and nutrient choice have also been shown to vary across reproductive states: salt and carbohydrate intake change with estrus cycle stage (Danielsen & Buggy, 1980; Wurtman & Baum, 1980); pregnant female rats increase their intake of sodium and protein, and lactating females increase their intake of protein, fat, calcium, and sodium (Cohen

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Reduced conversion of dehydroepiandrosterone into estrogens in women having hypogonadotropic hypogonadism associated with weight loss

Bulletti

Bolelli

et al. 1986

Journal of Steroid Biochemistry

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Experimental Analysis of Hormone Actions on the Hypothalamus, Anterior Pituitary, and Ovary

Cited by 7 publications

References 196 publications

Effects of Nutritional Level and Biological Type on Gonadotropin-Releasing Hormone-Induced Luteinizing Hormone Release and Plasma Progesterone, Estrone and Estradiol Concentrations in Pre- and Post-Partum Beef Heifers

Effects of Nutritional Level and Biological Type on Gonadotropin-Releasing Hormone-Induced Luteinizing Hormone Release and Plasma Progesterone, Estrone and Estradiol Concentrations in Pre- and Post-Partum Beef Heifers

Administration of ovarian steroid hormones does not change the reward effectiveness of lateral hypothalamic stimulation in ovariectomized rats

Reduced conversion of dehydroepiandrosterone into estrogens in women having hypogonadotropic hypogonadism associated with weight loss

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