Journal of the American Association for Laboratory Animal Science : JAALAS最新文献

{"title":"Mtb-Specific Interferon-Gamma ELISpot Assays Have Greater Sensitivity for Detecting Mtb Infection Compared to Tuberculin Skin Test in a Cohort of Experimentally M. tuberculosis-Infected Macaques.","authors":"Marshall A Malin, Pauline Maiello, H Jacob Borish, Daniel Fillmore, Jaime Tomko, Kara Kracinovsky, Jennifer Schober, Joshua Mattila, Edwin C Klein, Anita M Trichel, Anna Skorupski, Jaymahalaxmi R Geddedu-Hurdial, Sam Narainapoullé, Mark Rodgers, Reagan Walker, JoAnne L Flynn, Charles A Scanga, Philana Ling Lin","doi":"10.30802/AALAS-JAALAS-25-199","DOIUrl":"10.30802/AALAS-JAALAS-25-199","url":null,"abstract":"<p><p>Tuberculosis outbreaks in nonhuman primate (NHP) colonies can result in disastrous financial, scientific, animal welfare, and public health outcomes. Tuberculin skin testing (TST) has been the standard diagnostic method for identifying Mycobacterium tuberculosis (Mtb) infection in NHPs but has limited sensitivity and specificity. In humans, Mtb-specific interferon-γ release assays (IGRAs) have become the preferred diagnostic method, overcoming significant limitations of the TST. We compared the diagnostic qualities of the TST and IGRA in a cohort of 673 rhesus and cynomolgus macaques with experimental Mtb infection. Serial TST and IGRA data were curated retrospectively for animals before and after Mtb infection and temporally matched to assess sensitivity, specificity, and agreement between the 2 tests. The overall sensitivity of the IGRA was 0.84 compared with 0.49 sensitivity of the TST test in detecting Mtb infection. Specificity of the IGRA and the TST was 0.83 and 1.0, respectively, with an overall agreement rate of 72% between the 2 tests. Sensitivity peaked at 3-5 weeks postinfection for TST and 5-7 weeks for IGRA. Data from a second cohort of animals (n = 227) that were not experimentally infected with Mtb, but for whom testing was done for screening and investigational purposes, demonstrated an agreement rate of 96%. To our knowledge, this is the largest reported comparison of TST and IGRA testing in NHPs. Although IGRAs are more labor intensive than TSTs, our data suggest that IGRAs have better diagnostic accuracy in detecting Mtb infection. Our data also suggest that the threshold for a positive TST could be lowered to improve sensitivity.</p>","PeriodicalId":94111,"journal":{"name":"Journal of the American Association for Laboratory Animal Science : JAALAS","volume":" ","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13446392/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147936608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating the Physiological and Sedation Parameters of Zenalpha (Medetomidine and Vatinoxan Hydrochloride Injection) in Combination with Ketamine in Rhesus Macaques (Macaca mulatta).","authors":"Ulana Stasula, Kelsey Carroll, Takashi Taguchi, Kathryn Shelton, Diane Stockinger, Marie-Josee Lemoy, Greg Timmel","doi":"10.30802/AALAS-JAALAS-26-009","DOIUrl":"10.30802/AALAS-JAALAS-26-009","url":null,"abstract":"<p><p>Alpha-2 adrenergic agonists such as dexmedetomidine are widely used for sedation in rhesus macaques (Macaca mulatta) but are associated with undesired cardiovascular effects. Zenalpha (Dechra, Overland Park, KS), a combination of medetomidine and the peripheral α2 antagonist vatinoxan, has demonstrated improved physiologic stability in other species but has not been evaluated in nonhuman primates. This study assessed the cardiopulmonary effects and sedation quality of ketamine alone, ketamine combined with dexmedetomidine (500 μg/m2) for 30 or 60 minutes, and ketamine combined with Zenalpha (medetomidine 1 mg/m2 and vatinoxan 20 mg/m2) for 30 or 60 minutes in 10 adult rhesus macaques with 7-day washout intervals between immobilization events. A second study phase evaluated reduced α2 agonist doses, with each animal undergoing 2 additional immobilization events: ketamine + dexmedetomidine (250 μg/m2) and ketamine + Zenalpha (0.5 mg/m2). Physiologic parameters were recorded every 5 minutes, and sedation depth was scored every 10 minutes. Atipamezole (5,000 μg/m2 IM) was administered after the assigned immobilization period for dexmedetomidine and Zenalpha sessions (30 or 60 minutes). Across both phases, ketamine + Zenalpha produced higher heart rates, higher oxygen saturation, and lower mean arterial pressure compared with ketamine + dexmedetomidine while maintaining adequate sedation for up to 60 minutes. Reduced-dose protocols in phase 2 produced sedation comparable to full-dose combinations. These findings suggest that Zenalpha combined with ketamine may offer a more balanced cardiovascular profile than dexmedetomidine-based sedation protocols in rhesus macaques.</p>","PeriodicalId":94111,"journal":{"name":"Journal of the American Association for Laboratory Animal Science : JAALAS","volume":" ","pages":"1-11"},"PeriodicalIF":0.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13249125/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147847955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of Extended-Release Liposomal Bupivacaine on Postoperative Mechanical and Thermal Hypersensitivity in C57BL/6 Mice (Mus musculus).","authors":"Ashley I Wang, Marie P Duong, Jennifer R Frohlich, Lauren D Krueger, Tony L Yaksh, Keith J Jenné","doi":"10.30802/AALAS-JAALAS-26-029","DOIUrl":"10.30802/AALAS-JAALAS-26-029","url":null,"abstract":"<p><p>Systemic analgesics, such as opioids and nonsteroidal anti-inflammatory drugs, may be contraindicated in certain studies due to their mechanisms of action and risk for systemic effects. Local anesthetics (LAs) are therefore crucial in managing postoperative pain, potentially decreasing the need for systemic analgesics. However, the utility of standard formulation LAs is limited by their short duration. This study evaluated the use of a commercially available extended-release (XR) liposomal bupivacaine (LB) in a mouse paw incisional model. Our goal was to assess whether LB attenuates postoperative mechanical hypersensitivity (MH) and thermal hypersensitivity (TH). Adult female and male C57BL/6NCrl mice were randomly assigned to one of 3 groups: (1) 5 mg/kg SC meloxicam plus 3.25 mg/kg SC XR-buprenorphine (MELOX/XR-BUP); (2) 2 mg/kg intraincisional standard bupivacaine (SB); or (3) 6 mg/kg intraincisional LB. MH and TH were assessed on days -1 (baseline), 0 (2 hours postoperatively), 1, 2, 3, and 4 using von Frey and Hargreaves testing, respectively. Hind paw incisional surgery was performed on day 0. Both the MELOX/XR-BUP and SB groups demonstrated significant attenuation of MH on all postoperative days compared with baseline, while the LB group showed significant attenuation of MH on days 1-4. In the MELOX/XR-BUP group, there was a significant reduction in TH on days 1-3. In both the SB and LB groups, there was no significant reduction in TH across all postoperative days. Together, these data suggest that a single 6-mg/kg intraincisional dose of LB in C57BL/6NCrl mice does not attenuate TH over a 4-day postoperative period but does attenuate MH on postoperative days 1-4 in our incisional model. In comparing the treatments, we conclude that the relative ability of LB to attenuate postoperative MH and TH was inferior to that of MELOX/XR-BUP and comparable to that of SB in a mouse paw incisional model.</p>","PeriodicalId":94111,"journal":{"name":"Journal of the American Association for Laboratory Animal Science : JAALAS","volume":" ","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13446394/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148059340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ethical Perspectives Influence the Formation of Researchers' Perceptions of Experimental Conduct in a Preclinical Animal Experimentation Training Program.","authors":"Daehyun Han, Jungmin Lee, Hyelim Kwon, Dongyoub Shin, Byunghyun Choi, Youngil Park, Chulhee Kim, Byong Chang Jeong, Jae Berm Park","doi":"10.30802/AALAS-JAALAS-26-016","DOIUrl":"10.30802/AALAS-JAALAS-26-016","url":null,"abstract":"<p><p>Animal experimentation is conducted under regulatory and institutional frameworks that require ethical standards, safety management, scientific validity, and compliance with relevant guidelines. Accordingly, institutions that conduct preclinical research are responsible for providing structured training programs that prepare researchers to conduct animal experiments appropriately. However, empirical evaluations of such training programs and their outcomes remain limited. This study evaluated a comprehensive preclinical animal experimentation training program covering ethics, regulatory requirements, safety, and technical knowledge, using survey data collected from researchers who completed the program at Samsung Medical Center. The Kirkpatrick training evaluation model was applied as an analytical framework, and partial least squares structural equation modeling (PLS-SEM) was used to explore researchers' perceptions of animal experimentation conduct. The results demonstrated that the training program was associated with improved researcher perceptions, supported by acceptable reliability and validity of the measurement instrument. In particular, perceptions related to animal research ethics were significantly associated with experimental performance. An exploratory structural model was developed to identify key determinants of researcher perceptions and to support future refinement of training evaluation approaches. These findings suggest that well-designed training programs can foster ethically grounded and practically oriented attitudes among researchers, thereby strengthening accountability in animal experimentation and supporting the implementation of the Replacement, Reduction, and Refinement (3Rs) principles. This study provides evidence-based insights for institutions, training coordinators, and oversight bodies seeking to improve laboratory animal research training programs.</p>","PeriodicalId":94111,"journal":{"name":"Journal of the American Association for Laboratory Animal Science : JAALAS","volume":" ","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13446396/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148019503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Medetomidine Administration at the Subcutaneous GV20 Acupoint Compared with the Intramuscular Route in Guinea Pigs (Cavia porcellus): Sedation Score, Onset, and Duration of Action.","authors":"Eduardo I Esjaita, Santiago E Fuensalida, Nicolás H Giansanti, Pablo I Regner, Leonardo D Bernal, Florencia García-Blanco, Pablo E Otero, Samanta Waxman","doi":"10.30802/AALAS-JAALAS-25-179","DOIUrl":"10.30802/AALAS-JAALAS-25-179","url":null,"abstract":"<p><p>Recent research in both humans and animals has explored alternative routes for drug administration, such as pharmacopuncture, a technique involving the subcutaneous administration of low drug doses at acupuncture points. Among these points, the Governing Vessel 20 (GV20) has attracted particular interest in veterinary medicine due to its reported tranquilizing and sedative effects in humans and dogs. It has been proposed that administering sedative agents at this site may potentiate their effects, allowing for dose reduction while maintaining efficacy and minimizing adverse reactions. This study aimed to compare the sedative effects of medetomidine administered at the GV20 acupoint compared with the intramuscular route in adult guinea pigs (Cavia porcellus). Twenty animals received medetomidine (100 µg/kg) via both routes in a crossover design with a 2-week washout period. Sedation was assessed using a previously published scale (0-19). Sedation onset was defined as the time to achieve a score >3 of 19, and duration as the time to return to ≤3 of 19. Assessments were performed before and after administration at 1-minute intervals for the first 10 minutes, then every 2 minutes up to 30 minutes, and every 5 minutes thereafter until recovery. Comparisons of maximum sedation score, onset, and duration between routes were analyzed using the Wilcoxon signed-rank test. No significant differences were found in the maximum score, time to onset, or duration of sedation between the GV20 and intramuscular routes. These results indicate that, under the conditions of this study, medetomidine administration at GV20 did not enhance sedative efficacy or prolong the duration of action compared with the intramuscular route.</p>","PeriodicalId":94111,"journal":{"name":"Journal of the American Association for Laboratory Animal Science : JAALAS","volume":" ","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13249317/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147944437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Demographic History of a Prairie Vole (Microtus ochrogaster) Breeding Colony (2004-2020).","authors":"Adele M H Seelke, Christina L Hung, Sabrina L Mederos, Sophia Rogers, Tiffany Lam, Lauren A Meckler, Karen L Bales","doi":"10.30802/AALAS-JAALAS-26-030","DOIUrl":"10.30802/AALAS-JAALAS-26-030","url":null,"abstract":"<p><p>Prairie voles (Microtus ochrogaster) are highly social rodents that have become a valuable animal model for studying social attachment, pair bonding, parental care, and the neurobiological mechanisms underlying social behavior. In recent years, due in part to the publication of the prairie vole genome and deeper mechanistic understanding of their social behavior, prairie voles have become a more popular research model, especially for translational research. However, generating reliable and reproducible findings requires effective colony management, including thoughtful breeding strategies, consistent husbandry practices, and clear documentation. In this paper, we describe the demographic history of, and husbandry techniques employed for, our prairie vole breeding colony at the University of California, Davis from 2004 to 2020. Well-organized and transparent colony management allows for the preservation of informative behavioral traits in prairie voles and strengthens the impact of the prairie vole model across behavioral and biomedical science.</p>","PeriodicalId":94111,"journal":{"name":"Journal of the American Association for Laboratory Animal Science : JAALAS","volume":" ","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13446391/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148019287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Weight Loss and Constipation in a Rhesus Macaque (Macaca mulatta).","authors":"Diego Celdran-Bonafonte, Kathryn A O'Connell, Emily G Franklin, David G Besselsen, Cynthia J Doanne","doi":"10.30802/AALAS-JAALAS-26-053","DOIUrl":"10.30802/AALAS-JAALAS-26-053","url":null,"abstract":"","PeriodicalId":94111,"journal":{"name":"Journal of the American Association for Laboratory Animal Science : JAALAS","volume":" ","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13446398/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147944435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reproductive Complication in Rhesus Macaques (Macaca mulatta): Prevalence, Risk Factors, and Successful Surgical Resolution of Vaginal Prolapse Postpartum.","authors":"Kalie F Beckers, Katherine Johnson, Joseph W Greely, Kathrine P Falkenstein, Kasi E Russell-Lodrigue","doi":"10.30802/AALAS-JAALAS-26-040","DOIUrl":"10.30802/AALAS-JAALAS-26-040","url":null,"abstract":"<p><p>Pelvic organ prolapse (POP), including vaginal prolapse, is a prevalent reproductive condition in human and veterinary medicine, yet spontaneous cases are underreported in rhesus macaques (Macaca mulatta). This case study describes the clinical progression and successful surgical intervention of severe, recurrent vaginal prolapse in 2 pregnant, multiparous rhesus macaques at the Tulane National Biomedical Research Center (TNBRC). Over a multiweek period, one of the females experienced multiple prolapse episodes, including postpartum recurrence and failure of conservative management (manual reduction, suture retention techniques, and supportive care). The other female experienced multiple episodes during late gestation that continued despite conservative management. Definitive treatment was achieved through a novel abdominal approach involving uterine and cervical fixation to the rectus abdominis fascia, which resulted in anatomic correction and postoperative stability. A retrospective review of TNBRC records from 2005 to 2024 revealed 21 cases of vaginal prolapse with varied outcomes ranging from spontaneous resolution to euthanasia. Over this 20-year period, the prevalence was 4.71 per 1,000 females, with the most severe cases occurring in obese, multiparous individuals. This report demonstrates a practical and effective surgical alternative for managing severe or recurrent prolapse in rhesus macaques, particularly in reproductive-aged females where preservation of fertility and welfare is prioritized. The findings support the need for a species-specific prolapse grading system and highlight key risk factors such as parity, gestational age, infant size, and pelvic tissue integrity. These cases underline the importance of early detection, comprehensive supportive care, and individualized surgical planning in nonhuman primates, while providing a translational model for POP in women.</p>","PeriodicalId":94111,"journal":{"name":"Journal of the American Association for Laboratory Animal Science : JAALAS","volume":" ","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2026-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13446404/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148059297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of Short-Term Stall Size Housing on the Behavior and Welfare of Domestic Horses (Equus caballus).","authors":"Meryem Outouil, Erin K Daugherity, Lorin D Warnick, Pamela J Perry","doi":"10.30802/AALAS-JAALAS-25-152","DOIUrl":"10.30802/AALAS-JAALAS-25-152","url":null,"abstract":"<p><p>Single-stall housing is a common system used for horses in various settings, including racing stables, riding schools, teaching and research facilities. Adequate stall space is necessary for horses to lie down and make postural adjustments, both of which are essential for equine rest and welfare. The Guide for the Care and Use of Laboratory Animals recommends a stall size of 144 ft2. However, not all stalls meet this size requirement, and there is limited literature supporting its use in terms of animal welfare. This study used a crossover design to compare behavioral and physiologic variables indicative of welfare of horses housed in the standard recommended 144-ft2 stall compared with a smaller stall (136 ft2) to determine whether the smaller stalls affected horses' welfare and behavior. Eight horses (1,380-1,640 lb) were paired with preferred associates resulting in 4 pairs. One horse from each pair was randomly assigned to be housed in either the standard stall (144 ft2) or the smaller stall (136 ft2) for 4 days (from Monday morning through Friday morning), while the paired horse was housed in the opposite-sized stall. After this initial stall period, all horses were turned out to pasture for 9 days before being housed in the alternate-sized stall for an additional 4 days. Hay consumption, fecal output, and serum cortisol were quantified daily. Movement and duration of recumbency were measured with an accelerometer, and continuous video recordings of all horses were obtained while housed in the stalls (total of ∼96 hours per horse per stall condition). Behavioral variables (resting, locomotion, standing, consummatory, elimination, and stereotypic behavior) were scored every 5 minutes from the recordings and compared between stall conditions. Although several measures changed across days in both stall conditions, stall size did not affect the horses' hay consumption, fecal output, or cortisol concentrations, nor the duration of sternal or lateral recumbency as determined by accelerometer data. However, the duration of walking recorded by the accelerometer different between the 2 stall sizes with horses spending more time walking in the smaller stall (136 ft2). Analysis of video recordings also found no difference in percentage of time spent in sternal or lateral recumbency, rolling, standing, stand resting, walking, eating, or drinking. In conclusion, time budgets, food intake, fecal output, and cortisol concentrations were similar in horses housed in the standard-sized stall (144 ft2) compared with the smaller stall (136 ft2), suggesting that the reduced stall size did not result in observable changes in equine behavior or physiologic welfare indicators compared with the standard-sized stall.</p>","PeriodicalId":94111,"journal":{"name":"Journal of the American Association for Laboratory Animal Science : JAALAS","volume":" ","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13446403/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147793423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Onset of Analgesia in Rats (Rattus norvegicus) for Three Buprenorphine Formulations.","authors":"Eden D Alamaw, Kenzie E Schwartz, Mingyun Zhang, Benjamin D Franco, Katechan Jampachaisri, Monika K Huss, Cholawat Pacharinsak","doi":"10.30802/AALAS-JAALAS-26-003","DOIUrl":"10.30802/AALAS-JAALAS-26-003","url":null,"abstract":"<p><p>Extended-release buprenorphine has been extensively used in laboratory animal medicine, yet its onset of analgesia in rats remains largely unexplored. This study aimed to investigate the analgesic onset of 3 different extended-release buprenorphine formulations in rats. Our hypothesis was that the onset of all 3 buprenorphine formulations are comparable and are detectable as early as 5 minutes after administration in rats. Sprague-Dawley rats (both male and female, n = 40) were randomly assigned to 4 treatment groups: (1) saline (1 mL/0.1 kg SC, once); (2) Bup-ER (1.2 mg/kg SC, once); (3) Ethiqa-XR (0.65 mg/kg SC, once); and (4) LAT-Bup (Zorbium, 10 mg/kg transdermal, once). Thermal sensitivity (using a hot plate test) was assessed at time points of 5, 15, 30, 45, 60, 120, 180, and 240 minutes following drug administration. Results were as follows: (1) compared with the saline group, Bup-ER's thermal latency significantly increased at 45 (11.05 ± 1.13), 60 (12.5 ± 1.16), 120 (13.7 ± 1.24), 180 (12.48 ± 0.81), and 240 (11.64 ± 0.7) minutes; (2) Ethiqa-XR's thermal latency significantly increased at 180 (12.01 ± 0.6) and 240 (11.76 ± 0.81) minutes; and (3) LAT-Bup's thermal latency significantly increased at 120 (11.27 ± 1.16), 180 (13.97 ± 1.35), and 240 (14.8 ± 1.26) minutes. There were no differences between sexes. LAT-Bup and Bup-ER provided buprenorphine plasma levels exceeding the purported therapeutic threshold of 1 ng/mL by 5 minutes, while Ethiqa-XR exceeded the threshold at 45 minutes. We concluded that these 3 buprenorphine extended-release formulations did not exhibit a time to onset of analgesia within 5 minutes. This study demonstrates that despite all 3 extended-release formulations reaching a purported plasma therapeutic threshold earlier, the clinical onset of analgesia for the hot plate test was shortest for Bup-ER (45 minutes), followed by LAT-Bup (120 minutes) and Ethiqa-XR (180 minutes) in Sprague-Dawley rats.</p>","PeriodicalId":94111,"journal":{"name":"Journal of the American Association for Laboratory Animal Science : JAALAS","volume":" ","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2026-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13249297/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147725246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}