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Heroin intake decreases during the proestrus phase of the estrous cycle in female, Long-Evans rats. The purpose of this study was to (1) determine if proestrus-associated decreases in heroin intake extend across rat strains and (2) determine if proestrus-associated decreases in responding extend to a nondrug reinforcer. Female rats were implanted with intravenous catheters and trained to self-administer heroin. Estrous cycle was tracked daily for the duration of the study. During testing, Lewis, Sprague Dawley, and Long-Evans rats self-administered low (0.0025 mg/kg) and high (0.0075 mg /kg) doses of heroin and then self-administered sugar on fixed ratio (FR1) schedules of reinforcement. Heroin intake decreased significantly during proestrus in all three rat strains under at least one dose condition; however, sugar intake did not decrease during proestrus in any strain. These data suggest that responding maintained by heroin, but not a nondrug reinforcer, significantly decreases during proestrus in female rats and that these effects are consistent across rat strain.
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http://dx.doi.org/10.1016/j.bbr.2021.113329 | DOI Listing |
Front Pharmacol
August 2025
The First Clinical Medical College, Nanjing University of Chinese Medicine, Nanjing, Jiangsu, China.
In recent years, the potential application of Hook f. (TWHF) in the treatment of rheumatoid arthritis (RA) has garnered increasing attention in both academic research and clinical practice. However, the effective use of is limited in clinical practice by its severe toxic side effects.
View Article and Find Full Text PDFFood Chem Toxicol
September 2025
Public Health and Integrated Toxicology Division, Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Research Triangle Park, NC. Electronic address:
Background: Evaluation of the combined effects of endocrine-disrupting chemicals and dietary factors provides critical information for cumulative health risk assessment. Herein, we investigated the effects of cadmium (Cd) exposure and high fructose (HFr) diet on metabolic and reproductive health in female mice.
Methods: Female CD-1 mice were exposed to cadmium chloride (CdCl) (0.
Biomed Pharmacother
September 2025
Department of Embryology, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran. Electronic address:
Cyclophosphamide (CTX) is a chemotherapy alkylating agent that causes many side effects, including the occurrence of Premature ovarian failure (POF). The present study aims to investigate the effects of coumarin (COU), as an antioxidant, on apoptosis and oxidative stress in the CTX-induced POF mouse model. NMRI female mice were randomly divided into four groups: 1- The control group received 200 mg/kg normal saline every two days for 6 days.
View Article and Find Full Text PDFBiology (Basel)
July 2025
Academy of Romanian Scientists, Ilfov 3, 050044 Bucharest, Romania.
Modern life, characterized by constant exposure to artificial light from electronic devices, such as light-emitting diodes (LEDs), disrupts the natural circadian rhythm and induces important metabolic changes. The impact of blue light exposure on male and female rat's onset of puberty, hormonal and biochemical parameters was assessed by comparison between the four study groups: the control group (CTRL) maintained under normal light conditions, the group exposed to blue light from a mobile phone (MP), the group subjected to blue light from a computer screen (PC), and the group exposed to blue light from an LED lamp (LED). Both female and male rats exposed to PC and LED failed to thrive, with a significantly lower body weight intake than the CTRL group.
View Article and Find Full Text PDFBiol Reprod
September 2025
Clinic of Ruminants, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Sonnenstr. 16, Oberschleißheim 85764, Germany.
The oviductal fluid (OF) provides essential nutritional, mechanical, and physical support during the first four days of embryonic development. Among its physical properties, viscosity has been largely overlooked in embryo in vitro culture (IVC) media due to limited available data. In this study, we measured the viscosity of bovine OF from ex vivo samples and mimicked it during in vitro embryo culture.
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