{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/71356"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/71356","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Effects of Estradiol on Leydig Cell Function and Testicular Development in the Prepubertal Bull","abstract":"One group (E, n = 5) of beef bull calves was implanted with estradiol-17$\\beta$ (E$\\sb2$) from birth to 39 weeks of age. A second group (P, n = 5) received placebo. A third (EH, n = 5) and fourth (PH, n = 5) group of bull calves were treated similarly except that they were challenged at 7, 22 and 31 weeks with an intramuscular injection of human chorionic gonadotropin (hCG). Serum hormone levels were determined weekly. At 39 weeks of age, E and P calves were castrated for histologic evaluation of the testes and assessment of in vitro Leydig cell function. Serum E$\\sb2$ was greater than 100 pg/ml in all calves at birth but decreased to lower basal levels by day 7 in P and PH. Whereas serum testosterone (T) was observed to rise immediately following birth and remain elevated in P and PH, T did not rise (p $$ 0.1) in basal LH concentration was detected during this period. Serum follicle-stimulating hormone (FSH) was decreased (p $$ 0.1) in vitro. However, exposure to 10$\\sp{-6}$ M E$\\sb2$ increased T production (p $&lt;$ 0.05).","abstract_html":"One group (E, n = 5) of beef bull calves was implanted with estradiol-17<span class=\"etd-inline-math\">&beta;</span> (E$\\sb2$) from birth to 39 weeks of age. A second group (P, n = 5) received placebo. A third (EH, n = 5) and fourth (PH, n = 5) group of bull calves were treated similarly except that they were challenged at 7, 22 and 31 weeks with an intramuscular injection of human chorionic gonadotropin (hCG). Serum hormone levels were determined weekly. At 39 weeks of age, E and P calves were castrated for histologic evaluation of the testes and assessment of in vitro Leydig cell function. Serum E$\\sb2$ was greater than 100 pg/ml in all calves at birth but decreased to lower basal levels by day 7 in P and PH. Whereas serum testosterone (T) was observed to rise immediately following birth and remain elevated in P and PH, T did not rise (p $$ 0.1) in basal LH concentration was detected during this period. Serum follicle-stimulating hormone (FSH) was decreased (p $$ 0.1) in vitro. However, exposure to 10$\\sp{-6}$ M E$\\sb2$ increased T production (p $&amp;lt;$ 0.05).","abstract_has_math":true,"creators":["Sherman, Gary Bruce"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Veterinary Medical Science","degree_department":null,"school":null,"contributors":["Hixon, James E."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2014,"date_issued":"2014-12-16T06:35:55Z","date_published":"2014-12-16T06:35:55Z","updated_at":"2026-07-22T22:26:04Z","subjects":["Biology, Animal Physiology","Agriculture, Animal Pathology","Biology, Veterinary Science"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(UMI)AAI8908841"],"render_values":[{"text":"(UMI)AAI8908841","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/71356","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Hixon, James E."]},{"key":"dc:creator","label":"Author","values":["Sherman, Gary Bruce"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2014-12-16T06:35:55Z","10000-01-01","1988"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Veterinary Medical Science"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Biology, Animal Physiology","Agriculture, Animal Pathology","Biology, Veterinary Science"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/71356","(UMI)AAI8908841"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["One group (E, n = 5) of beef bull calves was implanted with estradiol-17$\\beta$ (E$\\sb2$) from birth to 39 weeks of age. A second group (P, n = 5) received placebo. A third (EH, n = 5) and fourth (PH, n = 5) group of bull calves were treated similarly except that they were challenged at 7, 22 and 31 weeks with an intramuscular injection of human chorionic gonadotropin (hCG). Serum hormone levels were determined weekly. At 39 weeks of age, E and P calves were castrated for histologic evaluation of the testes and assessment of in vitro Leydig cell function. Serum E$\\sb2$ was greater than 100 pg/ml in all calves at birth but decreased to lower basal levels by day 7 in P and PH. Whereas serum testosterone (T) was observed to rise immediately following birth and remain elevated in P and PH, T did not rise (p $$ 0.1) in basal LH concentration was detected during this period. Serum follicle-stimulating hormone (FSH) was decreased (p $$ 0.1) in vitro. However, exposure to 10$\\sp{-6}$ M E$\\sb2$ increased T production (p $&lt;$ 0.05).","Made available in DSpace on 2014-12-16T06:35:55Z (GMT). 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A third (EH, n = 5) and fourth (PH, n = 5) group of bull calves were treated similarly except that they were challenged at 7, 22 and 31 weeks with an intramuscular injection of human chorionic gonadotropin (hCG). Serum hormone levels were determined weekly. At 39 weeks of age, E and P calves were castrated for histologic evaluation of the testes and assessment of in vitro Leydig cell function. Serum E$\\sb2$ was greater than 100 pg/ml in all calves at birth but decreased to lower basal levels by day 7 in P and PH. Whereas serum testosterone (T) was observed to rise immediately following birth and remain elevated in P and PH, T did not rise (p $$ 0.1) in basal LH concentration was detected during this period. Serum follicle-stimulating hormone (FSH) was decreased (p $$ 0.1) in vitro. However, exposure to 10$\\sp{-6}$ M E$\\sb2$ increased T production (p $&lt;$ 0.05).","Made available in DSpace on 2014-12-16T06:35:55Z (GMT). No. of bitstreams: 1 8908841.pdf: 10390770 bytes, checksum: 41aec9e8a1bd904a1a1c83c82d5425f0 (MD5) Previous issue date: 1988","Embargo set by: Seth Robbins for item 71522 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","311 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1988."],"dc:identifier":["http://hdl.handle.net/2142/71356","(UMI)AAI8908841"],"dc:subject":["Biology, Animal Physiology","Agriculture, Animal Pathology","Biology, Veterinary Science"],"dc:title":["Effects of Estradiol on Leydig Cell Function and Testicular Development in the Prepubertal Bull"],"dc:type":["text"],"thesis:degree_discipline":["Veterinary Medical Science"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:26:04Z"}