Domestic animal endocrinology最新文献

{"title":"Effects of experimentally induced LH surge on local regulation of apelin/APJ in follicle during ovulation and corpus luteum formation in the cow","authors":"Bajram Berisha ,&nbsp;Michael W. Pfaffl ,&nbsp;Granit Thaqi","doi":"10.1016/j.domaniend.2025.106976","DOIUrl":"10.1016/j.domaniend.2025.106976","url":null,"abstract":"<div><div>The purpose of the study was to characterize the expression patterns of apelin and its receptor APJ (apelin/APJ) in superovulation induced follicles and corpus luteum (CL) tissue in the cow. Ovaries containing different classes of preovulatory follicles and early CL were timely defined during GnRH (gonadotropin hormone-releasing hormone) induced superovulation as follows: Before GnRH application, follicles group I: 0 h (control group) and after GnRH; group II: 4 h (corresponds to LH peak); group III:10 h; group IV: 20 h; group V: 25 h (corresponds close to ovulation) and group VI: 60 h (after ovulation - early CL). This experiment has made it possible for the direct comparison of the apelin/APJ system members in follicle tissue (theca interna plus granulosa cells) of periovulatory follicle groups with the subsequent CL tissue after ovulation (early CL, day 2-3). Relative gene expression levels were measured by RT-qPCR. The low level of apelin mRNA in the follicle group before the GnRH application (Group I), remained unchanged even in the follicle group II and III (4 h and 10 h after GnRH respectively). Apelin expression levels increased significantly by only 20 h after GnRH (group IV follicles: just before ovulation), remaining high during follicle ovulation (Group V: 20 h) and after ovulation (Group VI: early CL). In contrast, the low APJ mRNA level increased significantly in follicle group II (during LH peak) remaining high in all follicle groups before ovulation, as well as after ovulation (early CL). Our results indicate the possible involvement of apelin system (apelin/APJ) as a possible key regulator in the local mechanisms supporting final follicle maturation and ovulation, as well as the follicular-luteal transition and CL formation in cows.</div></div>","PeriodicalId":11356,"journal":{"name":"Domestic animal endocrinology","volume":"94 ","pages":"Article 106976"},"PeriodicalIF":2.1,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145217298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The transcriptome of the ovine choroid plexus is regulated by thyroid hormone but not by photoperiod","authors":"H. Dardente ,&nbsp;D. Lomet ,&nbsp;O. Lasserre ,&nbsp;A.A. Gonzalez ,&nbsp;X. Mialhe ,&nbsp;J. Cognié","doi":"10.1016/j.domaniend.2025.106975","DOIUrl":"10.1016/j.domaniend.2025.106975","url":null,"abstract":"<div><div>The photoperiodic control of seasonal functions requires the action of melatonin at the <em>pars tuberalis</em> of the pituitary and subsequent control of local thyroid hormone (TH) signaling by tanycytes lining the basolateral part of the third ventricle. Therefore, TH supply of tanycytes through the cerebrospinal fluid (CSF) produced by the choroid plexuses (CP) is central to photoperiodism. Here, the transcriptome of the CP of the lateral ventricles was established by RNAseq in ewes maintained under three experimental conditions: ewes exposed to a short photoperiod (SP; 8.5 h of light), intact ewes submitted to an acute 3-week exposure to a long photoperiod (LP-Sham; 15.5 h of light) and ewes thyroidectomized prior to the LP exposure (LP-THX). Photoperiod impacted the expression of 1169 genes (SP vs LP-Sham) while 575 genes were sensitive to TH (LP vs LP-THX). Compared to TH-responsive genes, photoperiod-responsive genes displayed rather weak transcriptional changes. In line with this, RT-qPCR for select candidate genes validated the impact of TH, but not that of photoperiod. We demonstrate weak expression of the melatonin MT1 receptor in the CP, which provides a functional rationale for this. In conclusion, the CP appears as a permissive tissue to the expression of TH-dependent seasonality governed by tanycytes rather than being an integral component of the melatonin-dependent photoperiodic response.</div></div>","PeriodicalId":11356,"journal":{"name":"Domestic animal endocrinology","volume":"94 ","pages":"Article 106975"},"PeriodicalIF":2.1,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145118482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Threshold dose of 1,25-dihydroxycholecalciferol-glycosides on mineral metabolism and circulating serotonin and dopamine in bovines","authors":"Douglas M. Souza ,&nbsp;Maximiliane A. Zambom ,&nbsp;Ryana C. Markmann ,&nbsp;Brenda Souza ,&nbsp;Tamires M. Schuster ,&nbsp;Kathrin Bühler ,&nbsp;Ériton E.L. Valente","doi":"10.1016/j.domaniend.2025.106963","DOIUrl":"10.1016/j.domaniend.2025.106963","url":null,"abstract":"<div><div>Plant-derived 1,25(OH)₂D₃-glycosides modulate calcium (Ca) and phosphorus (P) metabolism, but the safety of sustained oral supplementation in cattle remains unclear. The objective of this study was to establish a safe upper limit for dietary supplementation of 1,25(OH)₂D₃-glycosides in steers and to assess its impact on mineral and neurotransmitters metabolism. Six Holstein steers (452 ± 61.5 kg) were used in a replicated 3 × 3 Latin Square design. Treatments consisted of oral administration of 1,25(OH)₂D₃-glycosides at doses of 0, 0.2, and 0.4 µg/kg body weight (BW) for five consecutive days. Blood samples were collected prior to the initiation of treatment, as well as immediately before (0 h) and at 3, 6, 12, 24, 48, 72, 96, and 168 hours following the final dose on day 5. The serum Ca remained (<em>P &lt; 0.001</em>) elevated up to 72 h and 96 h following the final administration of 1,25(OH)₂D₃-glycoside at doses of 0.2 µg/kg BW and 0.4 µg/kg BW, respectively. In contrast, serum P concentrations remained significantly elevated (<em>P = 0.001</em>) for more than 168 hours post-treatment, regardless of the administered dose. No significant effects were observed on serum alkaline phosphatase (ALP) activity (<em>P = 0.298</em>), parathyroid hormone (PTH; <em>P = 0.183</em>) concentrations, or circulating serotonin (<em>P = 0.428</em>) and dopamine (<em>P = 0.846</em>). Additionally, no clinical signs consistent with vitamin D intoxication were observed. Oral supplementation with 1,25(OH)₂D₃-glycosides at doses up to 0.4 µg/kg BW for 5 days induces a sustained elevation in serum Ca and P concentrations, more evidently at higher dosages, without altering serum concentration of ALP, PTH, serotonin or dopamine indicating that 0.4 µg/kg BW dosage might be close to the upper threshold of 1,25(OH)₂D₃-glycosides in cattle while 0.2 µg/kg BW can be considered as safe.</div></div>","PeriodicalId":11356,"journal":{"name":"Domestic animal endocrinology","volume":"94 ","pages":"Article 106963"},"PeriodicalIF":2.1,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144917865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differential responsiveness and signaling pathways for prostaglandin F2a on chemokine mRNA in bovine corpus luteum and luteinized granulosa cells","authors":"Wenxiang Luo ,&nbsp;Lisa B. Wiltbank-Chau ,&nbsp;Hemanta K. Shrestha ,&nbsp;Milo C. Wiltbank","doi":"10.1016/j.domaniend.2025.106962","DOIUrl":"10.1016/j.domaniend.2025.106962","url":null,"abstract":"<div><div>Regulation of immune cells during luteolysis has been previously described, however inter- and intra-cellular pathways that mediate PGF_2α induction of immune cells in the bovine corpus luteum (CL) have not been clearly defined. Real-time PCR was used to measure chemokine mRNA and Western blotting used to measure phosphorylation of signaling proteins after PGF_2α treatment of early and mid-cycle CL and in similar-stage luteinized granulosa cells (LuGC). In Day 11 CL (with luteolytic capacity), PGF_2α induced expression of <em>CXCL8, CXCL2, CCL2</em>, and <em>CCL8</em> at 1 h after treatment and continued to stimulate the four chemokines at 10 h after treatment. In Day 4 CL (without luteolytic capacity), there was a less robust increase in chemokine mRNA at 1 h after PGF_2α with no detectable effect at 10 h after PGF_2α. In luteinized granulosa cells (LuGC), PGF_2α induced a dramatic increase in mRNA for <em>CXCL8</em> and <em>CXCL2</em> with no change in mRNA for <em>CCL2</em> and <em>CCL8</em>. In granulosa cells incubated for a similar time in conditions that did not induce luteinization, PGF_2α did not alter transcription of any of these chemokines. In mature LuGC, treatment with PGF_2α rapidly phosphorylated a key protein in the NFκB pathway, NFKBIA, and in the MAP kinase pathway, MAPK3, with no change in total amounts of these proteins. Moreover, in LuGC, induction by PGF_2α of <em>CXCL2</em> was inhibited by a PKC inhibitor and a NFκB pathway inhibitor. In addition, PGF_2α-regulated phosphorylation of NFKBIA was blocked by the PKC inhibitor. In contrast, induction of <em>CXCL8</em> by PGF_2α was inhibited by a MAP kinase inhibitor. Thus, PGF_2α induction of chemokines is closely related to luteolytic capacity. Further, two key chemokines, CXCL8 and CXCL2, seem to originate from large luteal cells through distinct signaling pathways that are activated by PGF_2α.</div></div>","PeriodicalId":11356,"journal":{"name":"Domestic animal endocrinology","volume":"93 ","pages":"Article 106962"},"PeriodicalIF":2.1,"publicationDate":"2025-08-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144886111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of leptin in mammalian oocyte developmental competence and pre-implantation embryo development","authors":"Miguel A. Velazquez","doi":"10.1016/j.domaniend.2025.106960","DOIUrl":"10.1016/j.domaniend.2025.106960","url":null,"abstract":"<div><div>Leptin is primarily involved in energy homeostasis and has been implicated in fertility. Leptin- and leptin receptor-deficient mouse models have demonstrated that expression of leptin signalling in the central nervous system is essential for ovulation. However, evidence from ruminants and other species gathered from models with physiological leptin signalling suggests that modulation of leptin may not play a major role in the attainment of ovulation in post-pubertal individuals, despite influencing ovarian steroidogenesis and folliculogenesis. <em>In vitro</em> studies indicate that leptin concentrations between 10 and 100 ng/ml may inconsistently enhance oocyte maturation across several species. However, most livestock studies report positive effects only at concentrations higher than those found in follicular fluid, raising questions about the physiological relevance of these findings. Similarly, in humans, leptin levels in follicular fluid show inconsistent correlations with oocyte maturation, further questioning the role of leptin in the completion of meiosis. In null mutant models of leptin or its receptor, leptin expression is required for pre-implantation development but does not appear to be essential for implantation. Furthermore, contradictory <em>in vitro</em> data on leptin-mediated effects during oocyte maturation and pre-implantation development across various species do not support an essential role of leptin in the ability of oocytes to form a blastocyst or in the progression of early embryos to the blastocyst stage. Overall, while the presence of leptin is crucial for ovulation and pre-implantation development, its modulation under physiological leptin signalling appears to have a minimal impact on blastocyst formation, suggesting a dispensable role in mammalian reproduction.</div></div>","PeriodicalId":11356,"journal":{"name":"Domestic animal endocrinology","volume":"93 ","pages":"Article 106960"},"PeriodicalIF":2.1,"publicationDate":"2025-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144842205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Osteopontin expression in prepubertal and adult dog testes and the effect of slow-release deslorelin implants (Suprelorin® 4.7 mg)","authors":"Narin Liman ,&nbsp;Orsolya Balogh ,&nbsp;Betül Fidan ,&nbsp;Linda Müller ,&nbsp;Aykut Gram","doi":"10.1016/j.domaniend.2025.106961","DOIUrl":"10.1016/j.domaniend.2025.106961","url":null,"abstract":"<div><div>Osteopontin (OPN) is a highly phosphorylated glycoprotein expressed in several cells, tissues, and tissue fluids, including the male reproductive system. Recent studies have indicated that OPN may be a potential fertility marker in male dogs. However, OPN expression and localization during testicular growth are still unclear, and the effect of pharmacological castration on testicular OPN expression in male dogs has not been studied to date. This study aimed to investigate and compare the expression and protein immunolocalization of OPN in the prepubertal (PRE) and adult dog (AD) testes, while also evaluating whether treatment of adult dogs (DES) with gonadotropin-releasing hormone (GnRH)-agonist deslorelin (Suprelorin® 4.7 mg implant) could alter the expression of testicular OPN. A significantly elevated OPN gene expression (p ≤ 0.007) was detected in the PRE dogs' testes than in AD and DES dogs. In addition, OPN mRNA expression was higher in DES dogs than in AD (p = 0.002). OPN-immunoreactivity was observed in all groups as granular staining in Sertoli and Leydig cell cytoplasm. Furthermore, in AD dogs, one or sometimes two OPN-positive granules were observed in round spermatids at stage V, and in elongating and elongated spermatids at stages I-III and VI-VIII of the spermatogenic cycle. Our results confirm the presence of OPN in the testes of prepubertal, adult, and deslorelin-induced spermatogenic and steroidogenic arrest dogs and reveal that infertile status, either developmental in PRE or induced in DES, affects testicular OPN expression.</div></div>","PeriodicalId":11356,"journal":{"name":"Domestic animal endocrinology","volume":"93 ","pages":"Article 106961"},"PeriodicalIF":2.1,"publicationDate":"2025-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144810502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of peptide cross reactivity in equine plasma using two adrenocorticotropic hormone immunoassays","authors":"Andy E Durham","doi":"10.1016/j.domaniend.2025.106959","DOIUrl":"10.1016/j.domaniend.2025.106959","url":null,"abstract":"<div><div>This study aimed to further define and quantify possible cross-reactive peptides when measuring plasma adrenocorticotropic hormone (ACTH) concentration in equids. Equine plasma samples were spiked with known concentrations of exogenous manufactured peptides comprising human ACTH_1-39, ACTH_18-39 (corticotropin-like intermediate lobe peptide, CLIP) and ACTH_7-38 (corticotropin inhibiting peptide, CIP). All samples were assayed in duplicate using Siemens Immulite 2000xpi chemiluminescent assay (CLA) and Tosoh AIA-900 immunoflurorescent assay (IFA). As expected, ACTH_1-39 was measured by both assays although higher values were reported using IFA (mean 132 % of actual concentrations) than CLA (mean 104 % of actual concentrations). ACTH_18-39 was detected by the CLA but not the IFA (mean 29 % actual concentration) whereas ACTH_7-38 was detected by the IFA, but not the CLA (mean 65 % actual concentration). The study further clarifies that these ACTH immunoassays are likely to report higher measured ACTH_1-39 concentrations than are actually present in the sample although additional work is needed to elucidate the diagnostic and pathophysiologic implications of these findings.</div></div>","PeriodicalId":11356,"journal":{"name":"Domestic animal endocrinology","volume":"93 ","pages":"Article 106959"},"PeriodicalIF":1.9,"publicationDate":"2025-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144491264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of milk production and endocrine profiles of dairy cows exposed to either white light-emitting diode or induction lighting","authors":"Y. Inabu ,&nbsp;Y. Takakura ,&nbsp;Y. Shinohara ,&nbsp;M. Sunadome ,&nbsp;R. Watanabe ,&nbsp;S. Kushibiki ,&nbsp;T. Sugino","doi":"10.1016/j.domaniend.2025.106958","DOIUrl":"10.1016/j.domaniend.2025.106958","url":null,"abstract":"<div><div>White light-emitting diodes (WLEDs) are characterized by their high blue light intensity, whereas induction lighting (IL) emits lower levels of blue light. This study investigated the effects of exposure to WLED and IL on milk production and physiological responses in dairy cows. Nine lactating Holstein cows [225 ± 32.5 days in milk, 710 ± 24.6 kg initial body weight (BW), 2.6 ± 1.6 parity] were kept under a 16:8 h light-dark cycle and assigned to two treatments for 3 wk each in a 2 × 2 crossover design: exposure to either WLED (443 nm peak wavelength, 231 lx) or IL (529 nm peak wavelength, 237 lx). During the dark period, light intensity was 0.0 lx. All cows were fed total mixed ration ad libitum. Milk samples were collected weekly, and serial blood sampling was performed on the last day of each treatment. Dry matter intake, BW, milk yield, and milk composition did not differ between treatments. However, plasma non-esterified fatty acids concentration tended to be higher for the WLED than for the IL (<em>P</em> = 0.09). In addition, plasma melatonin and cortisol concentrations were higher (<em>P</em> &lt; 0.01) for the WLED group than for the IL group. These findings suggest that differences in light wavelength between WLED and IL affect melatonin and cortisol secretion and may also impact lipid metabolism, without altering milk production performance.</div></div>","PeriodicalId":11356,"journal":{"name":"Domestic animal endocrinology","volume":"93 ","pages":"Article 106958"},"PeriodicalIF":1.9,"publicationDate":"2025-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144269992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Luteal features and serum concentrations of progesterone and hCG in dairy goats submitted to estrus induction followed by intrauterine or intramuscular hCG administration","authors":"Alice L. Martins ,&nbsp;Luana R. Côrtes ,&nbsp;Juliana N.D. Rodrigues ,&nbsp;Paulo Sergio C. Rangel ,&nbsp;Ana Lucia R. e S. Maia ,&nbsp;Felipe Z. Brandão ,&nbsp;Luiz Gustavo B. Siqueira ,&nbsp;Bruna W. de Freitas ,&nbsp;Jeferson F. Fonseca","doi":"10.1016/j.domaniend.2025.106957","DOIUrl":"10.1016/j.domaniend.2025.106957","url":null,"abstract":"<div><div>This study evaluated the effect of hCG administration by different routes on D7 (D0=estrus onset) on serum concentrations of hCG and progesterone (P4). Its role in the induction of accessory corpora lutea (aCL), total luteal area (TLA), and vascular area (VA) was assessed by ultrasonography (US). Forty-four goats had estrus induced with intravaginal sponges (60 mg of MAP, six days) plus 200 IU recombinant eCG and 131.5 μg cloprostenol via intramuscular (i.m.) 24 h before sponge removal. Goats received 300 IU hCG either via intrauterine (hCG-IU, n=8) or i.m. (hCG-IM, n=11) or 1 mL of saline i.m. (control, n=12). Estrus was detected and goats were mated with fertile bucks. On D21, goats from hCG-IU and hCG-IM presented more CLs than control ones (P&lt;0.05). The aCL was not detected in the control and differed (P&lt;0.05) between hCG-IU (25.0 %; 2/8) and hCG-IM (63.6 %; 7/11). TLA increased in hCG-IM between D13 and D17 (P&lt;0.05) and VA was higher (P&lt;0.05) in the hCG-IU on D13. On D7, the hCG concentration was similar among groups (P&gt;0.05), however, it increased (P&lt;0.05) on D7.5 in the hCG-IM and remained higher than hCG-IU and control until D8. The concentration of P4 did not differ (P&gt;0.05) among groups. The pregnancy rate did not differ (P&gt;0.05) between hCG-IM (91.0 %) and control (83.0 %) and both were higher (P&lt;0.05) than hCG-IU (25.0 %). In conclusion, despite a slight improvement in luteal perfusion, intrauterine administration of hCG showed limited benefits on the parameters studied, not promoting significant changes in the reproductive tract environment.</div></div>","PeriodicalId":11356,"journal":{"name":"Domestic animal endocrinology","volume":"93 ","pages":"Article 106957"},"PeriodicalIF":1.9,"publicationDate":"2025-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144269991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reverse triiodothyronine concentrations in hyperthyroid, healthy, and azotemic cats determined by ultra-performance liquid chromatography-tandem mass spectrometry","authors":"N.R. Wiesner ,&nbsp;F.K. Zeugswetter ,&nbsp;A. Hildebrand ,&nbsp;R. Klein ,&nbsp;E. Müller","doi":"10.1016/j.domaniend.2025.106956","DOIUrl":"10.1016/j.domaniend.2025.106956","url":null,"abstract":"<div><div>Without thyroid scintigraphy, diagnosing feline hyperthyroidism can be challenging. The primary aims of this study were the quantification of total 3,3′,5′-triiodothyronine (total reverse T3, TrT3) concentrations in hyperthyroid, healthy, and azotemic cats using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and to investigate its potential as a predictive marker for the diagnosis of hyperthyroidism. The hypothesis was that in feline hyperthyroidism rT3, representing the “inactivated” metabolite of T4, increases in relation to T4 and “active” T3. Left over samples of 138 hyperthyroid cats submitted for radioiodine treatment, 73 healthy cats and 83 cats with kidney disease were analyzed. Azotemic cats were included to represent cats with possible non-thyroidal illness syndrome. The healthy group was used to calculate reference limits and to investigate the influence of age and gender. UPLC-MS/MS detected both T3 isomers with high analytic sensitivity. TrT3 measurements correlated positively with total T4 (TT4, rSP = 0.937, <em>P</em> &lt; 0.001), and total T3 concentrations (TT3, rSP = 0.866, <em>P</em> &lt; 0.001). TT4 correlated positively with TT3 (rSP = 0.939, <em>P</em> &lt; 0.001). Hyperthyroid cats had higher TT4, TT3, and TrT3 concentrations as well as TrT3/TT4 ratios compared to the other groups (<em>P</em> &lt; 0.001), whereas the TT3/TrT3-ratios was lower (<em>P</em> &lt; 0.001). TrT3 exceeded TT3 concentrations in 85.5 % of the hyperthyroid cats. The optimum cutoff to identify hyperthyroidism determined by ROC-curve analysis was TrT3 &gt; 0.75 nmol/l (sensitivity 1, specificity 0.968). No effects of gender (<em>P</em> = 0.848) or age (<em>P</em> = 0.691) were observed. In conclusion, rT3 is the second most abundant thyroid hormone in feline hyperthyroidism, can be measured by UPLC-MS/MS with high diagnostic accuracy and its measurement opens new doors to investigate feline iodothyronine metabolism.</div></div>","PeriodicalId":11356,"journal":{"name":"Domestic animal endocrinology","volume":"93 ","pages":"Article 106956"},"PeriodicalIF":1.9,"publicationDate":"2025-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144269990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}