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Postnatal Dynamics of Circulating Steroid Hormones in Mule and Equine Neonates. Vet Sci 2022; 9:vetsci9110598. [PMID: 36356075 PMCID: PMC9696302 DOI: 10.3390/vetsci9110598] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/12/2022] [Accepted: 10/13/2022] [Indexed: 11/16/2022] Open
Abstract
It is necessary to study hormonal patterns from mules to recognize alterations and neonatal maladaptation. Our objective was to evaluate concentrations of hormones in mule (n = 6) and equine foals (n = 6). Blood was collected at T0, 1, 6 and 12 h after birth. Hormone concentrations were evaluated using liquid chromatography tandem mass spectrometry. Effects of time, group and interactions and regression analysis were evaluated (p < 0.05). There was a cubic and quadratic decline in mule and equine foals, respectively, for 3β,20α-dihydroxy-DHP. Mule foals were born with lower circulating 3β,20α-dihydroxy-DHP concentrations, which might be related to progestogen concentrations in mares with a hybrid placenta. Corticosterone and cortisol concentrations remained unchanged for the first hour post-foaling then declined in mule and equine foals (p < 0.0001). Dehydroepiandrosterone was the main androgen present. There was a decrease in dihydrotestosterone at 12 h (p = 0.002). Differences in the temporal patterns of secretion within each steroid class, pregnanes, corticoids, and androgens, suggest they were derived from different tissue sources, presumptively the placenta, adrenals and gonads of the fetus/neonate, respectively. Mule and horse foals were born without evidence of testosterone secretion. For the first time, steroid hormone levels were measured in neonatal mules, and this will provide insight into neonatal physiology that differs from equine and allow us to gain an understanding of mules that have rarely been studied. Further studies are needed to elucidate the effects of hybrid pregnancies in the steroid endocrinology of neonates.
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Cates KA, Atkinson S, Gabriele CM, Pack AA, Straley JM, Yin S. Testosterone trends within and across seasons in male humpback whales (Megaptera novaeangliae) from Hawaii and Alaska. Gen Comp Endocrinol 2019; 279:164-173. [PMID: 30904390 DOI: 10.1016/j.ygcen.2019.03.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Revised: 03/18/2019] [Accepted: 03/18/2019] [Indexed: 11/30/2022]
Abstract
Understanding reproductive profiles and timing of reproductive events is essential in the management and conservation of humpback whales (Megaptera novaeangliae). Yet compared to other parameters and life history traits, such as abundance, migratory trends, reproductive rates, behavior and communication, relatively little is known about variations in reproductive physiology, especially in males. Here, an enzyme immunoassay (EIA) for testosterone was validated for use in biopsy samples from male humpback whales. Analyses were conducted on 277 North Pacific male humpback whale blubber samples, including 268 non-calves and 9 calves that were collected in the Hawaiian breeding grounds and the Southeast Alaskan feeding grounds from 2004 to 2006. Testosterone concentrations (ng/g) were significantly different between non-calves sampled in Hawaii (n = 182) and Alaska (n = 86, p < 0.05) with peak testosterone concentrations occurring in the winter (January-March) and the lowest concentrations occurring in the summer (June-September). Fall and spring showed increasing and decreasing trends in testosterone concentrations, respectively. Blubber testosterone concentrations in non-calves and calves sampled in Alaska were not significantly different. Blubber and skin from the same individual biopsies (n = 37) were also compared, with blubber having significantly higher testosterone concentrations (p < 0.05) than skin samples. We found variability in testosterone concentration with age, suggesting that male humpbacks reach peak lifetime testosterone concentrations in the breeding grounds around age 8-25 years. The testosterone profile of male humpback whales follows a predictable pattern for capital breeders, where testosterone begins to increase prior to the breeding season, stimulating the onset of spermatogenesis. Incorporation of reproductive hormonal profiles into our overall understanding of humpback whale physiology will shed additional light on the timing of reproduction and overall health of the recently delisted Hawaii distinct population segment (DPS).
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Affiliation(s)
- Kelly A Cates
- University of Alaska Fairbanks, College of Fisheries and Ocean Sciences, Fisheries Department, Juneau Center, 17101 Pt. Lena Loop Road, Juneau, AK 99801, United States
| | - Shannon Atkinson
- University of Alaska Fairbanks, College of Fisheries and Ocean Sciences, Fisheries Department, Juneau Center, 17101 Pt. Lena Loop Road, Juneau, AK 99801, United States.
| | | | - Adam A Pack
- Departments of Psychology and Biology, University of Hawai'i at Hilo, 200 West Kawili Street, Hilo, HI 96720, United States; The Dolphin Institute, P.O. Box 6279, Hilo, HI 96720, United States
| | - Janice M Straley
- University of Alaska Southeast Sitka Campus, 1332 Seward Ave., Sitka, AK 99835, United States
| | - Suzanne Yin
- Hawai'i Marine Mammal Consortium, P.O. Box 6107 Kamuela, HI 96743, United States
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Katsumata E, Jaroenporn S, Ueda Y, Arai K, Katsumata H, Watanabe G, Taya K. Circulating gonadotropins and testicular hormones during sexual maturation and annual changes in male bottlenose dolphins (Tursiops truncatus). J Vet Med Sci 2017; 79:1899-1905. [PMID: 28993599 PMCID: PMC5709572 DOI: 10.1292/jvms.16-0544] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To reveal the reproductive biology in male bottlenose dolphins (Tursiops truncatus), circulating gonadotropins (follicle stimulating hormone [FSH] and luteinizing hormone [LH]) and testicular hormones
(testosterone and inhibin) were monitored for 8−12 years in 2 captive bottlenose dolphins (Mars and Regulus). During the study period, Mars was undergoing sexual maturation, whereas Regulus was already mature at the beginning of
the study. Assuming that Mars had reached sexual maturity when the significant increase in circulating testosterone levels was observed, serum concentration of inhibin was higher in the sexually immature stage than in the mature
stage, whereas the serum concentration of FSH was higher in the sexually mature stage than in the immature stage. No difference was observed in the LH levels between pre- and post-sexual maturation. There was a significant
increase in serum concentration of testosterone during spring in both animals. These results suggest that the mechanism responsible for regulating FSH secretion by inhibin functions during the sexually immature stage in this
species.
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Affiliation(s)
- Etsuko Katsumata
- Kamogawa Sea World, 1464-18 Higashi-cho, Kamogawa, Chiba 296-0041, Japan
| | - Sukanya Jaroenporn
- Primate Research Unit, Department of Biology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Yoko Ueda
- Laboratory of Veterinary Physiology, Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
| | - Kazutoshi Arai
- Kamogawa Sea World, 1464-18 Higashi-cho, Kamogawa, Chiba 296-0041, Japan
| | - Hiroshi Katsumata
- Kamogawa Sea World, 1464-18 Higashi-cho, Kamogawa, Chiba 296-0041, Japan
| | - Gen Watanabe
- Laboratory of Veterinary Physiology, Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan.,United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan
| | - Kazuyoshi Taya
- Laboratory of Veterinary Physiology, Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan.,International Marine Biological Research Institute, Kamogawa Sea World, 1464-18 Higashi-cho, Kamogawa, Chiba 296-0041, Japan
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Toishi Y, Tsunoda N, Kume K, Nagaoka K, Watanabe G, Taya K. PATHFAST, a novel chemiluminescent enzyme immunoassay for measuring estradiol in equine whole blood and serum. J Reprod Dev 2016; 62:631-634. [PMID: 27545960 PMCID: PMC5177982 DOI: 10.1262/jrd.2016-038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A novel chemiluminescent enzyme immunoassay system, PATHFAST, for the measurement of estradiol in horses was evaluated. The concentrations of estradiol in the whole blood and serum of mares were measured using PATHFAST and the estradiol concentrations measured by PATHFAST were compared with those measured by a time-resolved fluoro-immunoassay (FIA). To monitor physiological changes, serum estradiol concentrations in mares were measured using PATHFAST throughout the gestation period. The serum estradiol concentrations correlated highly with those in whole blood samples. The serum concentrations of estradiol measured by PATHFAST also correlated well with FIA. Circulating estradiol increased during mid-gestation and high levels of serum estradiol were maintained in late gestation, followed by an abrupt decline to term. These results demonstrate the utility of PATHFAST in equine clinics as an accurate diagnostic tool for the rapid assay of estradiol within 26 min using unextracted whole blood.
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Affiliation(s)
- Yuko Toishi
- Shadai Corporation, Hokkaido 059-1432, Japan
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DHAKAL P, HIRAMA A, NAMBO Y, HARADA T, SATO F, NAGAOKA K, WATANABE G, TAYA K. Circulating Pituitary and Gonadal Hormones in Spring-born Thoroughbred Fillies and Colts from Birth to Puberty. J Reprod Dev 2012; 58:522-30. [DOI: 10.1262/jrd.2011-025] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Pramod DHAKAL
- Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan
- Laboratory of Veterinary Physiology, Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
- Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan
- Laboratory of Veterinary Physiology, Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
| | - Akiko HIRAMA
- Miho Training Center, Japan Racing Association, Ibaraki 300-0415, Japan
- Miho Training Center, Japan Racing Association, Ibaraki 300-0415, Japan
| | - Yasuo NAMBO
- Department of Clinical Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan
- Hidaka Training and Research Center, Japan Racing Association, Hokkaido 057-0171, Japan
- Department of Clinical Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan
- Hidaka Training and Research Center, Japan Racing Association, Hokkaido 057-0171, Japan
| | - Takehiro HARADA
- Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan
- Laboratory of Veterinary Physiology, Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
- Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan
- Laboratory of Veterinary Physiology, Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
| | - Fumio SATO
- Department of Clinical Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan
- Hidaka Training and Research Center, Japan Racing Association, Hokkaido 057-0171, Japan
- Department of Clinical Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan
- Hidaka Training and Research Center, Japan Racing Association, Hokkaido 057-0171, Japan
| | - Kentaro NAGAOKA
- Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan
- Laboratory of Veterinary Physiology, Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
- Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan
- Laboratory of Veterinary Physiology, Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
| | - Gen WATANABE
- Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan
- Laboratory of Veterinary Physiology, Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
- Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan
- Laboratory of Veterinary Physiology, Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
| | - Kazuyoshi TAYA
- Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan
- Laboratory of Veterinary Physiology, Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
- Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan
- Laboratory of Veterinary Physiology, Cooperative Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
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Dhakal P, Tsunoda N, Nakai R, Nagaoka K, Nambo Y, Sato F, Taniyama H, Taya K. Post-Natal Dynamic Changes in Circulating Follicle-Stimulating Hormone, Luteinizing Hormone, Immunoreactive Inhibin, Progesterone, Testosterone and Estradiol-17β in Thoroughbred Colts until 6 Months of Age. J Equine Sci 2011; 22:9-15. [PMID: 24833982 PMCID: PMC4013995 DOI: 10.1294/jes.22.9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/20/2010] [Indexed: 11/28/2022] Open
Abstract
The aim of present study was to clarify the post-natal profile of follicle-stimulating
hormone (FSH), luteinizing hormone (LH), immunoreactive (ir)-inhibin, progesterone,
testosterone, and estradiol-17β, and their relationships in Thoroughbred colts. Six
hundred and thirty-six colts were used for the study. Single plasma samples from each
animal were harvested from the blood drawn through jugular venipuncture. The subjects were
born with high amounts of progesterone, testosterone, and estradiol-17β, all of which
dropped significantly and remained at lower levels till the end of 6 months. FSH decreased
transiently after birth until day 12 and then gradually increased to peak at day 100 which
then maintained in lesser levels towards the end of the studied period. LH was highest
during birth which decreased until day 26 and then increased slowly to sub-birth levels up
to day 90. Animals were born with high amounts of ir-inhibin. It dropped slowly and halved
by day 20 and then decreased towards rest of the studied period. The increase in FSH is
negatively correlated with the declining ir-inhibin levels. The early increase in FSH can
be the indication of early post-natal maturation of the hypothalamic pituitary testicular
axis that ultimately might be responsible for priming the testes for future
development.
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Affiliation(s)
- Pramod Dhakal
- Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan ; Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
| | | | - Rie Nakai
- Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan ; Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
| | - Kentaro Nagaoka
- Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
| | - Yasuo Nambo
- Hidaka Training Research Center, Japan Racing Association, Hokkaido 057-0171, Japan
| | - Fumio Sato
- Department of Veterinary Pathology, Rakuno Gakuen University, Hokkaido 069-850, Japan
| | - Hiroyuki Taniyama
- Department of Veterinary Pathology, Rakuno Gakuen University, Hokkaido 069-850, Japan
| | | | - Kazuyoshi Taya
- Department of Basic Veterinary Science, United Graduate School of Veterinary Sciences, Gifu University, Gifu 501-1193, Japan ; Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
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