Papers by Karina Gutierrez
Zygote, 2014
The Grb14 protein is a member of the Grb7 protein family. This protein family acts by binding to ... more The Grb14 protein is a member of the Grb7 protein family. This protein family acts by binding to tyrosine kinase receptors, promoting cell proliferation and differentiation. There is evidence of the involvement of tyrosine kinase factors in the bovine oocyte maturation process. However, Grb14 has not been studied for bovine cumulus-oocyte complexes (COCs). The aim of the present study was to characterize Grb14 mRNA expression in bovine COCs during follicular development. Furthermore, we demonstrated that the expression of Grb14 mRNA is not regulated by estradiol. mRNA expression of Grb14 was assessed in 480 COCs from follicles of different sizes (1-3, 4-6, 6-8 or >8 mm) by quantitative reverse transcription polymerase chain reaction (qRT-PCR). Grb14 mRNA expression decreased in COCs throughout follicular growth (P < 0.05). The role of estradiol in the expression of Grb14 mRNA in COCs was studied. Grb14 mRNA abundance did not differ in COCs cultured in the presence or absence of 17-estradiol or fulvestrant. In conclusion, we showed that Grb14 mRNA is downregulated in COCs during antral follicle development, a finding that suggests a role for Grb14 in oocyte competence.
Reproductive Toxicology, 2013
Hyperthyroidism may lead to a loss of sperm motility and an increase in oxidative stress (OS) in ... more Hyperthyroidism may lead to a loss of sperm motility and an increase in oxidative stress (OS) in testes and may cause male reproductive disorders. Thus, the use of compounds with antioxidant properties may be a strategy for preventing these disorders. The effect of resveratrol (RSV) on sperm motility and on variables of the antioxidant status in the testes of rats with triiodothyronine-induced hyperthyroidism (100μg/kg) was investigated. Hyperthyroid rats presented lower sperm motility, higher levels of lipid hydroperoxides and thiobarbituric reactive substances, lower catalase and glutathione peroxidase activities and higher glutathione-S-transferase activity in their testes than control animals. RSV treatment (1mg/kg and 10mg/kg) was able to prevent these effects in the hyperthyroid rats and had no effect in the control animals. In conclusion, RSV might be a strategy for therapeutic intervention to preserve sperm motility and to prevent OS in testes, preserving testicular function in those with hyperthyroidism.
Peptides, 2011
The kallikrein–kinin system (KKS) has been described as an important mediator of physiologic proc... more The kallikrein–kinin system (KKS) has been described as an important mediator of physiologic processes. Kallikreins use kininogen (KNG) as substrate to generate bradykinin, the main active peptide of the KKS that acts through two types of receptors, the B1R and the B2R. The goal of this study was to characterize some components of the KKS in different compartments of the ovary during the bovine ovulation process. The KNG, B1R and B2R mRNA expression patterns were assessed in theca and granulosa cells, as well as the bradykinin concentration and kallikrein-like activity in follicular fluid of bovine periovulatory follicles. To obtain a periovulatory follicle (≥12 mm), twenty-seven cows were submitted to estrus synchronization protocol and ovariectomized by colpotomy at 0, 3, 6, 12 or 24 h after a GnRH-analog injection (gonadorelin; 100 μg, IM). Follicular fluid was aspirated for enzymatic assays while granulosa and theca cells were harvested for mRNA analysis. The mRNA expressions in follicular cells were evaluated by real-time RT-PCR and data representation related to the cyclophilin housekeeping gene. The bradykinin concentration and kallikrein-like activity were measured in follicular fluid by enzymatic immunoassay and selective substrate cleavage, respectively. The B2R expression in theca cells and B1R expression in theca and granulosa cells showed different profiles during the periovulatory period (P < 0.05). The bradykinin concentration and kallikrein-like activity in the follicular fluid were different (P < 0.05) due to the time during the ovulation process. KNG mRNA expression was similar for both follicular cell types (P > 0.05). Taken together, these results provide an important characterization of the presence and possible KKS regulation during the bovine ovulation.► Kallikrein–kinin system is produced in the ovary during ovulation in bovine. ► Bradykinin and kallikrein have a regulation in follicular fluid during ovulation. ► The B1R expression is induced in both follicular cells. ► The B2R is constitutively expressed in granulosa cells and induced in theca cells. ► The study uses an in vivo approach to study monovulatory species.
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Papers by Karina Gutierrez