We previously showed that short-term hypo- and hyperthyroidism induce changes in neuropeptide glutamic-acid-isoleucine-amide (NEI) concentrations in discrete brain areas in male rats. To investigate the possible effects of hypo- and hyperthyroidism on NEI concentrations mainly in hypothalamic areas related to reproduction and behavior, female rats were sacrificed at different days of the estrous cycle. Circulating luteinizing hormone (LH), estradiol and progesterone concentrations were measured in control, hypothyroid (hypoT, treated with PTU during 7-9 days) and hyperthyroid (hyperT, l-T4 during 4-7 days) animals. Both treatments blunted the LH surge. Hypo- and hyperthyroidism increased estradiol concentrations during proestrus afternoon (P-PM), although hypoT rats showed lower values compared to control during proestrus morning (P-AM). Progesterone levels were higher in all groups at P-PM and in the hyperT during diestrus morning (D2). NEI concentrations were lower in hypoT rats during the estrous cycle except in estrus (E) in the peduncular part of the lateral hypothalamus (PLH). They were also reduced by both treatments in the perifornical part of the lateral hypothalamus (PeFLH) during P-PM. Hypothyroidism led to higher NEI concentrations during P-PM in the organum vasculosum of the lamina terminalis and anteroventral periventricular nucleus (OVLT+AVPV). The present results indicate that NEI concentration is regulated in a complex manner by hypo- and hyperthyroidism in the different areas studied, suggesting a correlation between NEI values and the variations of gonadal steroid levels during estrous cycle. These changes could be, in part, responsible for the alterations observed in the hypothalamic-pituitary-gonadal axis in these pathologies.
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http://dx.doi.org/10.1016/j.peptides.2013.08.016 | DOI Listing |
BMC Vet Res
January 2025
Theriogenology Department, Faculty of Veterinary Medicine, New-Valley University, New Valley, 725211, Egypt.
Background: Saidi sheep are one of the most important farm animals in Upper Egypt, particularly in the Assiut governorate. Since they can provide meat, milk, fiber, and skins from low-quality roughages, sheep are among the most economically valuable animals bred for food in Egypt. Regarding breeding, relatively little is known about the Saidi breed.
View Article and Find Full Text PDFSleep Biol Rhythms
January 2025
Laboratory of Animal Physiology, School of Agriculture, Meiji University, 1-1-1 Higashimita, Tama-Ku, Kawasaki, Kanagawa 214-8571 Japan.
The ovarian steroid hormones, estrogen and progesterone, the levels of which fluctuate dynamically with the estrous cycle, alter circadian behavioral rhythms in mammals. However, it remains unclear whether the sleep-wake rhythm fluctuates with the menstrual cycle in humans. To ascertain the relationship between the menstrual cycle and sleep-wake rhythms, we evaluated the objective and long-term sleep-wake rhythms of ten healthy women using a recently developed wearable device.
View Article and Find Full Text PDFActa Physiol (Oxf)
February 2025
Laboratory of Biological Rhythms, Institute of Physiology of the Czech Academy of Sciences, Prague, Czech Republic.
Aim: Exposure to light at night and meal time misaligned with the light/dark (LD) cycle-typical features of daily life in modern 24/7 society-are associated with negative effects on health. To understand the mechanism, we developed a novel protocol of complex chronodisruption (CD) in which we exposed female rats to four weekly cycles consisting of 5-day intervals of constant light and 2-day intervals of food access restricted to the light phase of the 12:12 LD cycle.
Methods: We examined the effects of CD on behavior, estrous cycle, sleep patterns, glucose homeostasis and profiles of clock- and metabolism-related gene expression (using RT qPCR) and liver metabolome and lipidome (using untargeted metabolomic and lipidomic profiling).
Reprod Toxicol
January 2025
Department of Morphology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil. Electronic address:
Saturated fat has been linked to cardiovascular diseases, leading to an increase in polyunsaturated fat consumption. The aim of the present study was to investigate the effects of three fat sources (coconut oil, lard and soybean oil) on metabolic and reproductive parameters in heterogenic mice. Female Swiss mice (5-6 weeks old; n=9/group) were divided into four experimental groups: control (CC), coconut oil (CO), lard (LA), and soybean oil (SO), and were orally given 0.
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