Endocrinology Commons^™

The Role Of Rfamide-Related Peptide 3 (Rfrp3) In Regulation Of The Neuroendocrine Reproductive And Growth Axes Of The Boar, Jennifer F. Thorson, Amy T. Desaulniers, Chanho Lee, Brett R. White, J. Joe Ford, Clay A. Lents

Department of Animal Science: Faculty Publications

RFamide-related peptide 3 (RFRP3) has been implicated in regulating reproduction and growth. This regulation appears to be dependent upon sex, species, physiological status, and developmental stage. The objective of the present study was to evaluate the effects of RFRP3 on circulating concentrations of luteinizing hormone (LH) and growth hormone (GH) in mature boars. The hypothesis was RFRP3 would reduce circulating concentrations of LH and increase concentrations of GH. Meishan boars (716.6±2.8 days of age; 125.0±12.4kg BW) were randomly assigned to treatment: saline (n=4) or RFRP3 (8.5mg; n=5). Plasma was collected at 15-min intervals during 3 periods: pre-treatment, treatment, and post-treatment. …

The Reproductive Biology Of The Finetooth Shark, Carcharhinus Isodon, In The Northwest Atlantic Ocean, Amanda N. Brown

UNF Graduate Theses and Dissertations

Shark fisheries are a multimillion dollar industry in the United States and have significant contributions both recreationally and commercially. In order to maintain this industry, fisheries must be properly managed. An understanding of life history and reproduction is crucial in order to adequately manage shark fisheries. The finetooth shark, Carcharhinus isodon, is a member of the small coastal shark (SCS) fishery complex. It is found in Atlantic waters from South Carolina to Florida and throughout the Gulf of Mexico. This species has recently come under increased fishing pressure and has previously been overfished. New data is needed in order …

Influence Of Steroids And Gonadotropins On Reproduction In Beef Cattle, Thomas L. Devine

Graduate Theses and Dissertations

The objective of this thesis was to evaluate the influence of steroids and gonadotropins on reproduction in beef cattle. In experiment 1, beef heifers were used to determine the influence of growth-promoting implants on growth, reproductive development, estrous behavior, and pregnancy rate. Heifers were assigned to 1 of 4 implant treatment groups: control (CON); trenbolone acetate (TBA); trenbolone acetate plus estradiol (TBA+E2) or zeranol (ZER). Heifers were implanted once, A.I. and exposed to bull during this experiment. Body weight, BCS, HH, RTS, estrous behavior and pregnancy data were collected throughout this experiment. Average daily gain of heifers was greater for …

Variations Of Ghrelin, Growth Hormone, And Insulin-Like Growth Factor I In The West Indian Manatee (Trichechus Manatus), Rachel Lynn Cimino

UNF Graduate Theses and Dissertations

The metabolic hormones ghrelin, growth hormone, and insulin-like growth factor I are influenced by developmental age, sex, and nutritional status in domestic and free-ranging species. However the role these hormones play has not previously been explored in sub-tropical/ tropical mammals. Furthermore, the seasonality of species with less dynamic environmental cues, such as the West Indian manatee, have not been studied. The West Indian manatee is and endangered species distributed in the southeastern United States and throughout the Caribbean basin, and its nutritional physiology is influenced by environmental factors. Understanding the hormone response to nutritional status in this species and its …

Impact Of Nutritional Status On The Somatotropic Axis And Ghrelin In Phocid Seals, Rachael Dailey

UNF Graduate Theses and Dissertations

Metabolic hormones and their axes, including the target tissues and receptors, regulate the tissue specific utilization of nutrients with in the body. The purpose of this research was to understand the hormonal control of complex nutrient partitioning mechanisms involved in young, growing animals. Specifically, this involved the investigation of metabolic hormones and the regulation of growth in two common species of phocids (true seals): harbor seal (Phoca vitulina) and Northern elephant seal (Mirounga angustirostris) pups. This longitudinal study examines young phocids from nutritional nadir through realimentation (realimentation) to investigate how metabolic hormones involved in both food intake and nutrient partitioning …

Flank Gland-Secreted Putative Chemosignals Pertaining To Photoperiod, Endocrine States, And Sociosexual Behavior In Golden Hamsters, Ying-Juan Liu, Da-Wei Wang, Lixing Sun, Jin-Hua Zhang, Jian-Xu Zhang

All Faculty Scholarship for the College of the Sciences

Behavioral studies have shown that flank glands are involved in chemical communication in golden hamsters Mesocricetus auratus but little chemical analysis has been conducted on volatiles arising from these glands. Using gas chromatography- mass spectrometry, we detected compounds from the flank glands of males, only eight of which were also produced in females. Based on these chemical data we performed a number of further experiments. By manipulating light we found that males exposed to short-photoperiods developed smaller flank glands than those exposed to long-photoperiods. Six flank gland volatiles reduced in relative abundance, which possibly coded for reproductive status of males …

Mice Deficient In The Serine/Threonine Protein Kinase Vrk1 Are Infertile Due To A Progressive Loss Of Spermatogonia, Matthew S. Wiebe, R. Jeremy Nichols, Tyler P. Molitor, Jill K. Lindgren, Paula Traktman

Nebraska Center for Virology: Faculty Publications

The VRK1 protein kinase has been implicated as a proproliferative factor. Genetic analyses of mutant alleles of the Drosophila and Caenorhabditis elegans VRK1 homologs have revealed phenotypes ranging from embryonic lethality to mitotic and meiotic defects with resultant sterility. Herein, we describe the first genetic analysis of murine VRK1. Two lines of mice containing distinct gene-trap integrations into the Vrk1 locus were established. Insertion into intron 12 (GT12) spared VRK1 function, enabling the examination of VRK1 expression in situ. Insertion into intron 3 (GT3) disrupted VRK1 function, but incomplete splicing to the gene trap rendered this allele hypomorphic (~15% of …

Immune-Endocrine Interactions In The Lizard Sceloporus Undulatus Hyacinthinus: Testing An Assumption Of The Immunocompetence Handicap Hypothesis, Mukta Chakraborty

All-Inclusive List of Electronic Theses and Dissertations

The immunocompetence handicap hypothesis (IHH) was proposed by Folstad and Karter ( 1992) to describe the role of the endocrine system in ensuring honesty of sexual signaling. Numerous studies have investigated the assumptions of the IHH, but currently there is mixed evidential support in favor of the IHH. The first chapter of this thesis is a review examinining these studies, their limitations, and proposed alternative models and future directions. The second chapter of this thesis presents a study in which we experimentally assesss the testosterone immunosuppression assumption in adult male Sceloporus undulatus lizards. We manipulated circulating androgen levels (Day 0) …

The Histology Of The Pineal Gland In Odocoileus Virginianus, Terry Michael De Villiers

Masters Theses

A total of 26 pineal glands from the white-tailed deer were histologically examined. Five different stains were utilized to determine various cell types present in pineal tissue. Connective tissue septa divide the pineal gland into incompletely separated lobules which are supplied by a very extensive vascular system. The pinealocyte is the most numerous cell in the gland and is most easily recognized by a prominent nucleus approximately 6-8 microns in diameter. The pinealocyte cytoplasm contains many minute granules. A distinct difference was noted in the histology of the oldest age deer pineal (age 7 years) when globular granules were observed …

The Effects Of Crowding On The Diurnal Ascorbic Acid Levels Of Albino Rats, Mary Jo Barr

Masters Theses

The adrenal physiology of the albino rat was studied through the measurement of adrenal ascorbic acid levels. A cyclic phenomenon was observed which follows the diel periodicity of the animal. Ascorbic acid values were found to be characteristically higher in males than in females. A similar difference was also seen in populations divided into young animals (body weight less than 175 grams) and old animals (body weight greater than 175 grams). Crowding, induced by manipulating the area of cage space per gram of body weight, was observed to be a definite stressor and caused the adrenal ascorbic acid levels to …

The Effects Of Acute Stress On Adrenal Ascorbic Acid Levels, Robert Joseph Collier

Masters Theses

The diurnal rhythm of adrenal ascorbic acid (DAR) displays an inverse relationship to the diurnal rhythm of circulating levels of plasma corticosteroids. Alloxan monohydrate, 175 mg/kg body weight was given subcutaneously to albino rats to determine the effect of the diabetic state on the DAR. A total of 200 female albino rats were divided into two study groups. Study Group I was composed of 150 animals divided into populations of 15, each including 3 controls. Study Group II was composed of populations of 5, each group containing all controls or all alloxinated rats. The populations of 15 were sacrificed at …

Phosphate Applications Affect The Coumestrol Level Of Medics, T Marshall, R. J. Parkin

Journal of the Department of Agriculture, Western Australia, Series 4

Western Australia has a million acres of medics including various cultivars of barrel medic, Medicago truncatula, and strand medic, M. littoralis. Both species contain coumestrol, a chemical thought to have caused delayed conception and reduced twinning rates among grazing ewes in New Zealand.

No infertility has been reported among ewes grazing medic pastures in Western Australia, but coumestrol levels in both species have often been high enough to suggest the possibility of oestrogenic responses among sheep grazing them.

Superphosphate Deficiency Raises Pasture Oestrogens, H G. Neil, T. Marshall

Journal of the Department of Agriculture, Western Australia, Series 4

A recent field experiment on established pastures at Esperance Downs Research Station has demonstrated a relationship between superphosphate application, pasture oestrogens and oestrogenic response in sheep.

Results of the experiment indicate that on phosphate deficient soils carrying oestrogenic clovers, the levels of oestrogenic materials in the pasture are increased if superphosphate applications are below those recommended for healthy pasture growth.

Control Of Clover Infertility In Sheep, H G. Neil, H. E. Fels, C. M. Francis

Journal of the Department of Agriculture, Western Australia, Series 4

A summary of practices recommended for the control of infertility caused by subterranean clover in West Australian sheep.

PROLONGED grazing of green subterranean clover pastures often reduces ewe fertility. In more extreme cases, obvious signs of clover disease occur.

Oestrogen Free Subterranean Clovers : Their Development And Prospects, C M. Francis

Journal of the Department of Agriculture, Western Australia, Series 4

SELDOM have plants received more publicity than the "oestrogen free" subterranean clovers developed by the University of Western Australia's Institute of Agriculture.

The production of oestrogen free clovers has attracted great popular interest, particularly among farmers in the southern sheep raising districts.

Clover Disease Of Sheep In Western Australia, A B. Beck, M. R. Gardiner

Journal of the Department of Agriculture, Western Australia, Series 4

DURING the past five years there has been a marked increase in the incidence of breeding abnormalities of sheep associated with the grazing of subterranean clover pastures.

This complex of diseases first became a major problem in Western Australia in the years following 1940 and eventually became known as "clover disease".