Thyroid blood profile in high-yielding dairy cows with different ovarian reactions to superovulatory treatment

The reaction of cow ovaries to superovulatory treatment significantly depends on the physiological state of the animal, primarily on its endocrine status. The available information indicates that thyroid hormones can affect the processes of ovarian folliculogenesis in cattle.Objective: To study the thyroid profile in the blood of high-yielding dairy cows in relation to the response of the ovaries to superovulatory treatment.Materials and methods. Thirty four cycles of superovulation stimulation in 16 Holstein cows were studied. After synchronization of the estrous cycle and superovulatory treatment, on the first day of insemination (Day 0), the number of follicles with a diameter of more than 5 mm was recorded in each ovary using an ultrasound scanner. Furthermore, on Day 0 and on the 7th day after insemination (Day 7), the blood was taken from the cows to analyze the content of sex steroids and thyroid hormones by ELISA. The ovarian reaction was assessed by the total number of detected follicles and was divided into 3 types: I – more than 12 follicles (strong), II – 8-12 follicles (moderate), III – less than 8 follicles (weak).Results. The content of sex steroid hormones in the blood of cows on Day 0 did not depend on the type of the ovarian response. By Day 7, the concentration of progesterone increased in most animals, but was 2.7-fold higher (P <0.01) in the case of the strong reaction (type I) than in the case of the weak reaction (type III). Conversely, the serum concentration of estradiol-17β decreased 1.1 times (P <0.05) in cows with the moderate ovarian response (type II). In animals with the type I reaction, the content of thyroxine (T4) in the blood declined 1.2 times (P <0.05) one week after insemination. During the study period, there was also a reduction in the concentration of total triiodothyronine (T3) and reverse T3 (rT3) in cows with ovarian responses of types I and II (1.1-1.3 times, P <0.01-0.05). Concurrently, on Day 0, the T3 content in the blood of individuals with the type II reaction was 1.2-fold higher (P <0.05) than in individuals with the type III reaction. Totally, a positive relationship was found between the concentration of estradiol-17β and the concentration of thyroid hormones: for T4 – in the case of the type II ovarian response (r = 0.44, P <0.05), for T3 – in the case of the type I and II responses ( r = 0.57-0.64, P <0.001-0.05), for rT3 – in the case of the type III response (r = 0.52, P <0.01).Conclusions. Thus, the content of triiodothyronine in the blood of high-yielding dairy cows on the day of insemination is associated with the ovarian response to superovulatory treatment. In addition, during one week after insemination, the state of the thyroid system and its relationship with the level of estradiol-17β in the blood differ with different reactions of the ovaries to the introduction of exogenous gonadotropic hormones.

In Vitro Investigations of miR-33a Expression in Estrogen Receptor-Targeting Therapies in Breast Cancer Cells

(1) Background: Increased fatty acid synthesis leads to the aggressive phenotype of breast cancer and renders efficiency of therapeutics. Regulatory microRNAs (miRNAs) on lipid biosynthesis pathways as miR-33a have potential to clarify the exact mechanism. (2) Methods: We determined miR-33a expression levels following exposure of MCF-7 and MDA-MB-231 breast cancer cells to estrogen receptor (ER) activator (estradiol-17β, E2) or anti-estrogens (ICI 182,780, Fulvestrant, FUL) at non-cytotoxic concentrations. We related miR-33a expression levels in the cells to cellular lipid biosynthesis-related pathways through immunoblotting. (3) Results: miR-33a mimic treatment led to significantly downregulation of fatty acid synthase (FASN) in MCF-7 cells but not in MDA-MB-231 cells in the presence of estradiol-17β (E2) or Fulvestrant (FUL). In contrast to the miR-33a inhibitor effect, miR-33a mimic co-transfection with E2 or FUL led to diminished AMP-activated protein kinase α (AMPKα) activity in MCF-7 cells. E2 increases FASN levels in MDA-MB-231 cells regardless of miR-33a cellular levels. miR-33a inhibitor co-treatment suppressed E2-mediated AMPKα activity in MDA-MB-231 cells. (4) Conclusions: The cellular expression levels of miR-33a are critical to understanding differential responses which include cellular energy sensors such as AMPKα activation status in breast cancer cells.

252 Impact of Pre- and Postnatal Nutritional Extremes on Tonic Secretion of Gonadotropins and Feedback Responsiveness to Estradiol in Sexually Mature Heifers

Objectives were to test the hypotheses that nutritional extremes during prenatal development interact with postnatal nutrition during the juvenile period of heifers to impact 1) tonic secretion of gonadotropins, and 2) estradiol-17β (E2) negative and positive feedback responsiveness in adulthood. Heifers were selected from a larger population programmed nutritionally using a 3 x 2 factorial arrangement of pre- and postnatal diets. Beginning at 90 days of pregnancy, Bos indicus-influenced cows (n = 95) were fed to achieve body condition scores (BCS; 1–9 scale) of 3–3.5 (L; thin), 5.5–6 (M; moderate), or 7.5–8 (H; obese) by onset of the third trimester and maintained thereafter. Heifer offspring were weaned at 3–3.5 months of age and assigned to either a low- (L; 0.5 kg/day) or high-gain (H; 1.0 kg/day) diet until 8 mo. of age, then fed a common diet until puberty. Heifers (n = 18; 6/grp) representing HH, MH and LL combinations were ovariectomized postpubertally (17.1 mo. of age) and received E2 replacement. In Exp. 1, blood samples were collected at 10-min intervals to evaluate pulsatile secretion of LH and FSH for 5.5 hours. In Exp. 2, heifers received E2 (2.4 ug/kg I.M.), with blood sampling at 30-min to 1-h intervals for 30 h. Heifers in the MH (1.25 ± 0.11 ng/mL) group tended (P &lt; 0.09) to have greater LH pulse amplitude compared to HH (0.91 ± 0.14 ng/mL) and LL (0.96 ± 0.09 ng/mL); otherwise, frequency, amplitude, and mean concentrations of LH and FSH did not differ among groups. Exogenous E2 (Exp. 2) suppressed (P &lt; 0.0001) mean plasma concentrations of LH and FSH equally among groups, then stimulated equivalent surges of LH beginning at 14 ± 0.02 h, with only two FSH surges detected. Neither pre- nor postnatal nutrition affected E2 negative or positive feedback in this study.

Gonad development and blood plasma profile of female bada fish (Rasbora sp.) by giving a combination of the hormones estradiol and spirulina in the feed

This study aimed to evaluate the effect of the combination of estradiol-17β hormone and spirulina in feed on blood plasma biochemistry, histology, and gonad development of female bada fish (Rasbora argyrotaenia). The research method were an experimental study using a completely randomized design with four treatment combinations and four replications, namely without the addition of the estradiol-17β hormone and spirulina (P0), the addition of the estradiol-17β hormone at 7 g kg-1 feed (P1), the addition of spirulina at 30 g kg-1 feed (P2) and the addition of the estradiol-17β hormone at 7 g kg-1 feed and spirulina at 30 g kg-1 feed. Female bada fish (4.22±1.28 g) were kept in an aquarium measuring 100x50x50 cm3 with a density of seven individuals per aquarium. Fish were fed the treatment twice daily, with 3% of the biomass for six weeks. The test parameters were estradiol-17β hormone concentration, egg diameter, blood plasma glucose concentration, blood plasma total cholesterol concentration, and gonadal histology observations. The experimental results showed that the concentration of the estradiol-17β hormone in the body plasma of treatments P1 and P3 was statistically significantly different (P<0.05) compared to treatments P0 and P2. The combination of estradiol-17β hormone and spirulina added to the feed gave not significantly different results (P>0.05) on blood plasma biochemistry and egg diameter of bada fish broodstock. A combination of estradiol-17β hormone and spirulina hormones in the feed resulted in better P1 and P3 treatments with higher plasma concentrations of the estradiol-17β hormone. Observations of gonadal development from histology showed that the bada fish gonads belonged to the asynchronous type.

Central μ-opioid receptor antagonism blocks glucoprivic LH pulse suppression and gluconeogenesis/feeding in female rats

Energetic status often affects reproductive function, glucose homeostasis and feeding in mammals. Malnutrition suppresses pulsatile release of the gonadotropin-releasing hormone (GnRH)/luteinizing hormone (LH) and increases gluconeogenesis and feeding. The present study aims to examine whether β-endorphin-μ-opioid receptor (MOR) signaling mediates the suppression of pulsatile GnRH/LH release, and an increase in gluconeogenesis/feeding induced by malnutrition. Ovariectomized female rats treated with a negative feedback level of estradiol-17β (OVX + low E2) receiving 2-deoxy-D-glucose (2DG), an inhibitor of glucose utilization, intravenously (iv), were used as a malnutrition model. An administration of D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP), a selective MOR antagonist, into the 3 rd ventricle blocked the suppression of the LH pulse and increase in gluconeogenesis/feeding induced by iv 2DG administration. Histological analysis revealed that arcuate Kiss1 (kisspeptin gene)-expressing cells and preoptic Gnrh1 (GnRH gene)-expressing cells co-expressed little Oprm1, while around 10% of arcuate Slc17a6 (glutamatergic marker gene)-expressing cells co-expressed Oprm1. Further, the CTOP treatment decreased the number of fos-positive cells in the paraventricular nucleus (PVN) in OVX + low E2 rats treated with iv 2DG, but failed to affect the number of arcuate fos-expressing Slc17a6-positive cells. Taken together, these results suggest that the central β-endorphin-MOR signaling mediates the suppression of pulsatile LH release and that the β-endorphin may indirectly suppress the arcuate kisspeptin neurons, a master regulator for GnRH/LH pulses during malnutrition. Furthermore, the current study suggests that central β-endorphin-MOR signaling is also involved in gluconeogenesis and an increase in food intake by directly or indirectly acting on the PVN neurons during malnutrition in female rats.

Controlling the cannibalism of African catfish juvenile by 17β‒estradiol hormone administration and the stocking density determination

An effort to increase the production of juvenile catfish is limited by the high mortality rate, especially caused by cannibalism. The hormonal treatment has been conducted as an effort to control cannibalism. This study used completely randomized factorial design, consisted of six treatments and three replications. There were two factors examined in this study, the first factor was different doses of 17β‒estradiol hormone (0, 30, and 60 mg estradiol‒17β/kg) incorporated in the feed, and the second factor was stocking density (150 and 300 fish/m2). Juvenile catfish with the size of 4.0 ± 0.1 cm were reared for 30 days in the 84 L aquarium. The results showed that hormone treatment could reduce cannibalism rate, type-I and II cannibalism compared to control (P<0.05). The results showed that the lowest of mortality was obtained in the treatment B (17β‒estradiol administration of 30 mg/kg, at stocking density of 150 fish/m2; P<0.05). The lowest cortisol level was found in treatment F, and the highest estradiol level was found in treatment F (17β‒estradiol administration of 60 mg/kg, at stocking density of 300 fish/m2; P<0.05). The lowest of blood glucose level was found in treatment B (P<0.05). The highest specific weight growth was found in the stocking density of 150 fish/m2 (P<0.05). The results of this study indicated that administration of 17β‒estradiol in feed could reduce the level of cannibalism in African catfish juvenile. Keywords: cannibalism, Juvenile, catfish, estradiol‒17β, cortisol ABSTRAK Upaya untuk meningkatkan produksi benih ikan lele dibatasi oleh tingginya angka kematian, terutama yang disebabkan oleh kanibalisme. Pendekatan hormonal telah dilakukan sebagai upaya pengendalian kanibalisme. Penelitian ini menggunakan rancangan acak lengkap faktorial, terdiri dari enam perlakuan dan tiga ulangan. Ada dua faktor yang diteliti dalam penelitian ini, faktor pertama adalah dosis hormon 17β‒estradiol yang berbeda (0, 30, dan 60 mg/kg) yang diberikan melalui pakan, dan faktor kedua adalah padat tebar (150 dan 300 ekor/m2). Benih ikan lele berukuran 4.0 ± 0.1 cm dipelihara selama 30 hari di akuarium (84 L). Hasil penelitian menunjukkan bahwa perlakuan hormon dapat menurunkan tingkat kanibalisme tipe‒I dan II dibandingkan kontrol (P<0.05). Hasil penelitian menunjukkan bahwa mortalitas terendah diperoleh pada perlakuan B (pemberian 17β‒estradiol 30 mg/kg, pada padat tebar 150 ekor/m2; P<0.05). Kadar kortisol terendah ditemukan pada perlakuan F, dan kadar estradiol tertinggi ditemukan pada perlakuan F (pemberian 17β‒estradiol 60 mg/kg, pada padat tebar 300 ekor/m2; P<0.05). Kadar glukosa darah terendah ditemukan pada perlakuan B (P<0.05). Pertumbuhan bobot spesifik tertinggi ditemukan pada padat tebar 150 ekor/m2 (P<0.05). Hasil penelitian ini menunjukkan bahwa pemberian hormon 17β‒estradiol dengan dosis 30 mg/kg pakan, dan padat tebar 150 ekor/m2 dapat menurunkan tingkat kanibalisme pada benih ikan lele di Afrika. Kata kunci: kanibalisme, juvenil, lele, 17β‒estradiol, kortisol