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Nutrients Jun 2024Previous studies have reported that TT genotype carriers of the adenosine A2a receptor () gene rs5751876 polymorphism have better ergogenic and anti-inflammatory... (Randomized Controlled Trial)
Randomized Controlled Trial
Previous studies have reported that TT genotype carriers of the adenosine A2a receptor () gene rs5751876 polymorphism have better ergogenic and anti-inflammatory responses to caffeine intake compared to C allele carriers. The aim of the present study was twofold: (1) to investigate the association of the rs5751876 polymorphism with acute caffeine supplementation on hormonal (growth hormone and testosterone) response to resistance exercise (RE); (2) to examine the relationship between the rs5751876 polymorphism and the resting levels of growth hormone and testosterone in athletes who are light caffeine consumers. A double-blind, crossover, placebo-controlled study involving 30 resistance-trained men (age 21.7 ± 4.1) was conducted to assess the impact of caffeine supplementation on serum growth hormone (GH) and testosterone (TS) levels before, immediately after, and 15 min post-RE. One hour before engaging in resistance exercise, subjects were randomly administered 6 mg of caffeine per kg of body mass or a placebo (maltodextrin). After a 7-day washout period, the same protocol was repeated. Resting testosterone and growth hormone levels were examined in the sera of 94 elite athletes (31 females, age 21.4 ± 2.8; 63 males, age 22.9 ± 3.8). Caffeine consumption led to significantly greater increases in GH and TS in men with the TT genotype compared to C allele carriers. Furthermore, in the group of athletes, carriers of the TT genotype had significantly higher testosterone ( = 0.0125) and growth hormone ( = 0.0365) levels compared to C allele carriers. In conclusion, the gene rs5751876 polymorphism may modify the effect of caffeine intake on the hormonal response to exercise.
Topics: Humans; Caffeine; Male; Double-Blind Method; Cross-Over Studies; Resistance Training; Receptor, Adenosine A2A; Young Adult; Testosterone; Adult; Female; Dietary Supplements; Athletes; Polymorphism, Single Nucleotide; Genotype; Human Growth Hormone; Polymorphism, Genetic; Exercise
PubMed: 38931158
DOI: 10.3390/nu16121803 -
International Journal of Molecular... Jun 2024Increased fructose consumption and chronic stress, the major characteristics of modern lifestyle, impact human health; however, the consequences of their combination on...
Increased fructose consumption and chronic stress, the major characteristics of modern lifestyle, impact human health; however, the consequences of their combination on the uterus remain understudied. In this study, we investigated contractile activity, morphology, and intracellular activity of antioxidant enzymes in uteri from virgin Wistar rats subjected to liquid fructose supplementation and/or unpredictable stress over 9 weeks. Contractile activity and uterine response to oxytocin or adrenaline were examined using isolated bath chambers. Fructose supplementation, irrespective of stress, affected uterine morphology by increasing endometrium while decreasing myometrium volume density, attenuated uterine response to increasing doses of oxytocin, and increased glutathione peroxidase activity. Stress, irrespective of fructose, attenuated dose-dependent adrenaline-induced uterine relaxation. Stress, when applied solely, decreased mitochondrial superoxide dismutase activity. In the combined treatment, irregular estrous cycles and both reduced response to oxytocin and to adrenaline (as a consequence of fructose consumption and exposure to stress), along with fructose-related alteration of uterine morphology, were detected. In conclusion, fructose and stress affect uterine contractile activity, irrespective of each other, by inducing completely distinct responses in isolated uteri. In the combined treatment, the effects of both factors were evident, suggesting that the combination exerts more detrimental effects on the uterus than each factor individually.
Topics: Animals; Female; Fructose; Rats; Uterine Contraction; Rats, Wistar; Oxytocin; Uterus; Epinephrine; Stress, Physiological; Stress, Psychological; Superoxide Dismutase; Dietary Supplements; Myometrium; Antioxidants
PubMed: 38928475
DOI: 10.3390/ijms25126770 -
International Journal of Molecular... Jun 2024The neuropeptide vasopressin is known for its regulation of osmotic balance in mammals. Arginine vasotocin (AVT) is a non-mammalian homolog of this neuropeptide that is...
The neuropeptide vasopressin is known for its regulation of osmotic balance in mammals. Arginine vasotocin (AVT) is a non-mammalian homolog of this neuropeptide that is present in fish. Limited information suggested that vasopressin and its homologs may also influence reproductive function. In the present study, we investigated the direct effect of AVT on spermatogenesis, using zebrafish as a model organism. Results demonstrate that AVT and its receptors (, , , and ) are expressed in the zebrafish brain and testes. The direct action of AVT on spermatogenesis was investigated using an ex vivo culture of mature zebrafish testes for 7 days. Using histological, morphometric, and biochemical approaches, we observed direct actions of AVT on zebrafish testicular function. AVT treatment directly increased the number of spermatozoa in an androgen-dependent manner, while reducing mitotic cells and the proliferation activity of type B spermatogonia. The observed stimulatory action of AVT on spermiogenesis was blocked by flutamide, an androgen receptor antagonist. The present results support the novel hypothesis that AVT stimulates short-term androgen-dependent spermiogenesis. However, its prolonged presence may lead to diminished spermatogenesis by reducing the proliferation of spermatogonia B, resulting in a diminished turnover of spermatogonia, spermatids, and spermatozoa. The overall findings offer an insight into the physiological significance of vasopressin and its homologs in vertebrates as a contributing factor in the multifactorial regulation of male reproduction.
Topics: Animals; Zebrafish; Male; Spermatogenesis; Vasotocin; Testis; Receptors, Vasopressin; Zebrafish Proteins; Spermatozoa; Cell Proliferation; Spermatogonia
PubMed: 38928267
DOI: 10.3390/ijms25126564 -
International Journal of Molecular... Jun 2024The physiology of reproduction has been of interest to researchers for centuries. The purpose of this work is to review the development of our knowledge on the... (Review)
Review
The physiology of reproduction has been of interest to researchers for centuries. The purpose of this work is to review the development of our knowledge on the neuroendocrine background of the regulation of ovulation. We first describe the development of the pituitary gland, the structure of the median eminence (ME), the connection between the hypothalamus and the pituitary gland, the ovarian and pituitary hormones involved in ovulation, and the pituitary cell composition. We recall the pioneer physiological and morphological investigations that drove development forward. The description of the supraoptic-paraventricular magnocellular and tuberoinfundibular parvocellular systems and recognizing the role of the hypophysiotropic area were major milestones in understanding the anatomical and physiological basis of reproduction. The discovery of releasing and inhibiting hormones, the significance of pulse and surge generators, the pulsatile secretion of the gonadotropin-releasing hormone (GnRH), and the subsequent pulsatility of luteinizing (LH) and follicle-stimulating hormones (FSH) in the human reproductive physiology were truly transformative. The roles of three critical neuropeptides, kisspeptin (KP), neurokinin B (NKB), and dynorphin (Dy), were also identified. This review also touches on the endocrine background of human infertility and assisted fertilization.
Topics: Humans; Ovulation; Female; Neurosecretory Systems; Animals; Pituitary Gland; Kisspeptins; Neurokinin B; Luteinizing Hormone; Gonadotropin-Releasing Hormone; Dynorphins; Hypothalamus
PubMed: 38928237
DOI: 10.3390/ijms25126531 -
International Journal of Molecular... Jun 2024We examined whether the administration of growth hormone (GH) improves insulin resistance in females of a non-obese hyperglycemic mouse model after birth with low birth...
We examined whether the administration of growth hormone (GH) improves insulin resistance in females of a non-obese hyperglycemic mouse model after birth with low birth weight (LBW), given that GH is known to increase muscle mass. The intrauterine Ischemia group underwent uterine artery occlusion for 15 min on day 16.5 of gestation. At 4 weeks of age, female mice in the Ischemia group were divided into the GH-treated (Ischemia-GH) and non-GH-treated (Ischemia) groups. At 8 weeks of age, the glucose metabolism, muscle pathology, and metabolome of liver were assessed. The insulin resistance index improved in the Ischemia-GH group compared with the Ischemia group ( = 0.034). The percentage of type 1 muscle fibers was higher in the Ischemia-GH group than the Ischemia group ( < 0.001); the muscle fiber type was altered by GH. In the liver, oxidative stress factors were reduced, and ATP production was increased in the Ischemia-GH group compared to the Ischemia group ( = 0.014), indicating the improved mitochondrial function of liver. GH administration is effective in improving insulin resistance by increasing the content of type 1 muscle fibers and improving mitochondrial function of liver in our non-obese hyperglycemic mouse model after birth with LBW.
Topics: Animals; Female; Mice; Insulin Resistance; Disease Models, Animal; Hyperglycemia; Liver; Human Growth Hormone; Humans; Pregnancy; Recombinant Proteins; Oxidative Stress; Infant, Low Birth Weight
PubMed: 38928001
DOI: 10.3390/ijms25126294 -
Genes Jun 2024is a LIM-homeodomain transcription factor that affects body size in mammals by regulating the secretion of pituitary hormones. Akita, Shiba Inu, and Mame Shiba Inu dogs...
is a LIM-homeodomain transcription factor that affects body size in mammals by regulating the secretion of pituitary hormones. Akita, Shiba Inu, and Mame Shiba Inu dogs are Japanese native dog breeds that have different body sizes. To determine whether plays a role in the differing body sizes of these three dog breeds, we sequenced the gene in the three breeds, which led to the identification of an SNP in codon 280 (S280N) associated with body size. The allele frequency at this SNP differed significantly between the large Akita and the two kinds of smaller Shiba dogs. To validate the function of this SNP on body size, we introduced this change into the gene of mice. Homozygous mutant mice (S279N) were found to have significantly increased body lengths and weights compared to heterozygous mutant (S279N) and wild-type (S279N) mice several weeks after weaning. These results demonstrate that a nonsynonymous substitution in plays an important role in regulating body size in mammals.
Topics: Animals; LIM-Homeodomain Proteins; Transcription Factors; Mice; Body Size; Dogs; Polymorphism, Single Nucleotide; Gene Frequency; Male; Female
PubMed: 38927675
DOI: 10.3390/genes15060739 -
Biomedicines Jun 2024Hypothyroidism is a frequently diagnosed endocrine disorder. Common signs and symptoms include fatigue, cold intolerance, hoarseness, dry skin, constipation, a slow...
Hypothyroidism is a frequently diagnosed endocrine disorder. Common signs and symptoms include fatigue, cold intolerance, hoarseness, dry skin, constipation, a slow relaxation phase of deep tendon reflexes, and bradycardia. However, some patients may exhibit atypical signs and symptoms, which can result in diagnostic confusion. Pituitary hyperplasia resulting from longstanding primary hypothyroidism was first described by Niepce in 1851. It is usually asymptomatic, but sometimes, in addition to symptoms of overt hypothyroidism, patients may complain of headaches, hypopituitarism, visual field impairment, and hyperprolactinemia. Furthermore, on imaging, pituitary hyperplasia can be mistaken for a pituitary adenoma. Distinguishing between the two is crucial, as their management differs; the former often responds to thyroid hormone replacement therapy, while the latter might need treatment with surgery and/or radiotherapy. Here we describe a patient who developed pituitary hyperplasia in the setting of longstanding uncompensated primary hypothyroidism due to a lack of compliance with levothyroxine replacement therapy. We also review the clinical, laboratory, and radiologic findings of the case reports available in the literature up to now in order to improve the knowledge and the care of the disease.
PubMed: 38927575
DOI: 10.3390/biomedicines12061368 -
Biomolecules Jun 2024The increasing utilization of Glucagon-like Peptide-1 receptor agonists (GLP-1 RAs) in managing type 2 diabetes mellitus has raised interest regarding their impact on... (Review)
Review
The increasing utilization of Glucagon-like Peptide-1 receptor agonists (GLP-1 RAs) in managing type 2 diabetes mellitus has raised interest regarding their impact on thyroid function. In fact, while these agents are well known for their efficacy in glycemic control and weight management, their association with thyroid disorders requires clarification due to the complex interplay between thyroid hormones and metabolic pathways. Thyroid dysfunction commonly co-occurs with metabolic conditions such as diabetes and obesity, suggesting a profound interconnection between these systems. This review aims to contribute to a deeper understanding of the interaction between GLP-1 RAs and thyroid dysfunction and to clarify the safety of GLP-1 RAs in diabetic patients with thyroid disorders. By synthesizing existing evidence, this review highlights that, despite various studies exploring this topic, current evidence is inconclusive, with conflicting results. It is important to note that these drugs are relatively recent, and longer-term studies with larger sample sizes are likely needed to draw clearer conclusions. Currently, no existing guidelines provide definitive directions on this clinical issue; however, it is advisable to include thyroid function tests in the routine screening of diabetic patients, particularly those treated with GLP-1 Ras, with the goal of optimizing patient care and management.
Topics: Humans; Glucagon-Like Peptide-1 Receptor; Thyroid Gland; Diabetes Mellitus, Type 2; Thyrotropin; Hypoglycemic Agents; Neoplasms; Thyroid Neoplasms
PubMed: 38927090
DOI: 10.3390/biom14060687 -
BMC Endocrine Disorders Jun 2024Advanced maternal age may affect the intrauterine environment and increase the risk of neurodevelopmental disorders in offspring. Thyroid hormones are critical for fetal...
BACKGROUND
Advanced maternal age may affect the intrauterine environment and increase the risk of neurodevelopmental disorders in offspring. Thyroid hormones are critical for fetal neurological development but whether maternal age influences fetal thyroid hormone levels in euthyroid mothers is unknown.
OBJECTIVE
This study evaluated the association between cord blood thyroid hormones and maternal age, fetal sex, maternal thyroid function, and other perinatal factors.
METHODS
The study population consisted of 203 healthy women with term singleton pregnancies who underwent elective cesarean section. Maternal levels of free T3 (fT3), free T4 (fT4) and TSH before delivery, and cord levels of fT3, fT4 and TSH were measured. Spearman's correlation coefficient and multiple linear regression analyses were performed to determine the correlation between cord thyroid hormone parameters and maternal characteristics.
RESULTS
There were no significant differences in maternal serum or cord blood thyroid hormone levels between male and female births. In multivariate linear regression analysis, maternal age and maternal TSH values were negatively associated with the cord blood levels of fT3 in all births, after adjusting for confounding factors. Maternal age was more closely associated with the cord blood levels of fT3 in female than in male births.
CONCLUSION
The inverse association between maternal age and cord blood levels of fT3 in euthyroid pregnant women suggested an impact of maternal aging on offspring thyroid function.
Topics: Humans; Female; Maternal Age; Adult; Male; Pregnancy; Fetal Blood; Infant, Newborn; Triiodothyronine; Sex Factors; Thyroid Function Tests; Thyrotropin
PubMed: 38926806
DOI: 10.1186/s12902-024-01631-3 -
Scientific Reports Jun 2024Previously, we demonstrated the expression of visfatin in porcine reproductive tissues and its effect on pituitary endocrinology. The objective of this study was to...
Previously, we demonstrated the expression of visfatin in porcine reproductive tissues and its effect on pituitary endocrinology. The objective of this study was to examine the visfatin effect on the secretion of steroid (P, E) and prostaglandin (PGE, PGF), the mRNA and protein abundance of steroidogenic markers (STAR, CYP11A1, HSD3B, CYP19A1), prostaglandin receptors (PTGER2, PTGFR), insulin receptor (INSR), and activity of kinases (MAPK/ERK1/2, AKT, AMPK) in the porcine corpus luteum. We noted that the visfatin effect strongly depends on the phase of the estrous cycle: on days 2-3 and 14-16 it reduced P, while on days 10-12 it stimulated P. Visfatin increased secretion of E on days 2-3, PGE on days 2-3 and 10-12, reduced PGF release on days 14-16, as well as stimulated the expression of steroidogenic markers on days 10-12 of the estrous cycle. Moreover, visfatin elevated PTGER mRNA expression and decreased its protein level, while we noted the opposite changes for PTGFR. Additionally, visfatin activated ERK1/2, AKT, and AMPK, while reduced INSR phosphorylation. Interestingly, after inhibition of INSR and signalling pathways visfatin action was abolished. These findings suggest a regulatory role of visfatin in the porcine corpus luteum.
Topics: Animals; Corpus Luteum; Female; Swine; Nicotinamide Phosphoribosyltransferase; Estrous Cycle; Receptor, Insulin; Progesterone; Receptors, Prostaglandin; Dinoprost
PubMed: 38926439
DOI: 10.1038/s41598-024-65102-4