Effects Of Exogenous Hormones Research Articles

Effects of cloprostenol and oxytocin on ultrasonographic changes of uterine horns in postpartum primiparous Hu sheep

This study aimed to evaluate the effects of exogenous hormones on postpartum ultrasonographic changes of uterine horn in Hu sheep. 90 nulliparous Hu sheep were divided into three groups according to the number of lambs. Each group was further randomly subdivided into three groups (n = 10), a control group (sodium chloride), a PG group (cloprostol), and a PG+OT group (cloprostol + oxytocin). The effects of different treatments on ultrasonographic changes of uterine horn and reproductive performance of ewes were determined after the treatment. Then, 90 nulliparous ewes were divided into a control group, PG group, and PG+OT group according to hormone injections received. Each group (n = 30) consisted of 10 single, 10 twin, and 10 triple ewes. Changes in the levels of hormones P4, LH, FSH, and E2 in the serum of postpartum ewes, the time of the first estrus, and the conception rate were detected. Results showed that the higher the lambing rate, the slower the rate of ultrasonographic changes of uterine horn. The rate of ultrasonographic changes of uterine horn in the PG+OT group was faster than that in respective PG and the control groups. Caruncle diameter was not affected by the number of lambs or hormone treatment. After delivery, the concentrations of P4 and LH increased rapidly and remained at a relatively high level, while the concentration of E2 increased in all ewes. The PG+OT group had lower P4 concentrations compared to the control group, but higher LH, FSH, and E2 levels. The time to first postpartum estrus was significantly shorter in the PG+OT group, but differences in pregnancy rate were not significant. Thus, PG+OT treatment can significantly accelerate postpartum ultrasonographic changes of uterine horn, which can prepare postpartum ewes for the next reproductive cycle.

Effects of Exogenous Hormones on Spawning Performances, Serum Gonadotropin and Sex Steroid Hormone in Manchurian Trout (Brachymystax lenok) during Sexual Maturation

The objective of this study was to investigate the effects of salmon gonadotropin releasing hormone analog (S-GnRH-A) and human chorionic gonadotropin (HCG) on the serum levels of gonadotropins (GtHs) and sex steroid hormones in Manchurian trout during sexual maturity. Females in the treatment group were injected with 20 µg/kg S-GnRH-A and 400 IU/kg HCG, whilst males were injected with half the amount. Blood samples were collected at 0, 5, 10, and 20 days post injection (dpi). The results showed an increase in female follicle-stimulating hormone (FSH) levels in the treatment group at 5 dpi, and from 5 dpi onwards, a difference was observed between the groups, with higher FSH levels in the treatment group compared to the control group. In males, FSH levels showed group differences at only 5 dpi (p < 0.05) and were higher in the treatment group. In females, luteinizing hormone (LH) peaked at 10 dpi in the treatment group, and there were differences between the two groups at 10 dpi and 20 dpi. In males, LH was significantly higher in the treatment group than in the control group at 5 dpi and 10 dpi (p < 0.05). In females, estradiol (E2) was significantly higher in the treatment group than in the control group at 5 dpi and 10 dpi (p < 0.05), whereas in males, the difference between the two groups was only observed at 5 dpi (p < 0.05). The female testosterone (T) level in the treatment group was significantly higher than that of the control group at 5 dpi and 10 dpi (p < 0.05), while T levels were significantly higher in the male treatment group than in the control group at 5 dpi (p < 0.05). The level of 17α–hydroxyprogesterone (17α-OHP) in the females of the treatment group was significantly higher than that of the control group at 5 dpi and 10 dpi (p < 0.05), and 17α-OHP levels were significantly higher in the male treatment group than in the control group at 10 and 20 dpi (p < 0.05). The fish were successfully spawned after S-GnRH-A and HCG injections, and brood amount, fertilization rate, and hatching rate were significantly increased (p < 0.05). This study provides a framework for a better understanding of the mechanisms of exogenous hormone-mediated control of reproduction in Manchurian trout.

Effect of Exogenous Hormones in Combination with Dopamine Antagonists in Breeding of Indian Major Carps

Effect of intraperitoneal injection of different inducing agents viz., pituitary gland (PG) extract, PG + domperidone (DOM), PG + pimozide (PIM) (all in two split doses) and ovaprim (in single dose) on ovulation and spawning in three Indian major carps such as rohu, catla and mrigal were investigated. Injection of PG extract alone to rohu, catla and mrigal resulted in ovulation of 93.3, 90.6 and 100% individuals, respectively. The spawning success achieved was 91.6, 71.8 and 100% in rohu, catla and mrigal, respectively. PG at the same dose alongwith dopamine antagonist (DOM/PIM) resulted in ovulation in all the individuals of the three species of carp but partial spawning to complete spawning was observed in them. The present study revealed that the domperidone alongwith hormonal suspension is more effective in rohu and mrigal, while pimozide with hormonal suspension is more effective in catla.

Effects of oral contraceptives and menopausal hormone therapy on the risk of rheumatoid arthritis: a prospective cohort study.

Oral contraceptives (OC) and menopausal hormone therapy (MHT) contain exogenous sex hormones and are used by millions of women around the world. However, their effect on the development of rheumatoid arthritis (RA) is still debated and the current literature suggests that they may exert opposite effects on the risk of RA. The present study aimed to estimate the effects of exogenous hormones on the development of RA, both during the reproductive lifespan and later in life. The association between OC and RA, as well as between MHT and late-onset RA (LORA), was investigated using time-dependent Cox regression modelling in white British women from the UK Biobank (n = 236 602 and n = 102 466, respectively) and replicated in women from all ethnic groups. OC use was associated with a decreased risk of RA in ever-users [hazard ratio (HR) = 0.89; 95% CI = 0.82-0.96], as well as in current (HR = 0.81; 0.73-0.91) and former users (HR = 0.92; 0.84 -1.00), compared with never-users. In contrast, MHT use was associated with an increased risk of LORA in ever-users (HR = 1.16; 1.06-1.26) as well as in former users (HR = 1.13; 1.03-1.24) compared with never-users. OC use appears to protect against RA, while MHT may increase the risk of LORA. This study provides new insights into the possible inverse effect of exposure to different exogenous sex hormones on the risk of RA.

Effect of Exogenous Plant Growth Regulators and Rejuvenation Measures on the Endogenous Hormone and Enzyme Activity Responses of Acer mono Maxim in Cuttage Rooting.

The cuttage rooting method for Acer species is difficult to achieve a good efficacy as trees maintain good characteristics at the rejuvenation stage, thus improving the rooting of Acer species. The addition of exogenous hormones and rejuvenation can improve the rooting effect of cuttings; however, the specific regulatory mechanism is still unclear. Here, Acer mono Maxim rejuvenation and non-rejuvenation cuttings were used as test subjects, to investigate the effects of exogenous hormones on the activities of endogenous hormones and antioxidant enzymes in the rooting process of young cuttings. The results showed that exogenous growth-regulating substances significantly improved the rooting rate of A. mono. Exogenous hormones naphthylacetic acid (NAA) + indolebutyric acid (IBA) increased the initial levels of the endogenous hormones, indoleacetic acid (IAA) and abscisic acid (ABA), and the enzyme activities of peroxidase (POD) and polyphenol oxidase (PPO). Rejuvenation treatment prolonged the time of increase in ABA content and indoleacetic acid oxidase (IAAO) activity at the root primordium induction stage, while increasing trans-zeatin riboside (ZR) content and decreasing POD enzyme activity in cuttings. These results demonstrate that A. mono cuttings can achieve the purpose of improving the rooting rate by adding the exogenous hormone (NAA + IBA), which is closely related to the changes of endogenous hormone content and enzyme activity, and these changes of A. mono rejuvenation cuttings are different from non-rejuvenation cuttings.

Melatonin in Th17/Treg differentiation: the contribution of the hormone's own production by T lymphocytes

The hormone melatonin is involved in regulation of functioning of almost all organs and systems of the organism. In the immune system, T lymphocytes are an important target of melatonin: they express specific melatonin receptors with different affinities – membrane MT1 and MT2 and nuclear RORa, as well as intracellular molecules that nonspecifically bind melatonin at high concentrations. Moreover, many in vitro studies reveal their own production of melatonin by T lymphocytes in response to polyclonal activation and its involvement as autocrine or paracrine factor in the induction of IL-2 and IL-2 receptor (IL-2R) synthesis by T cells, with melatonin receptors involvement in implementation of these effects. Since IL-2/IL-2R-dependent signal is a key event in T lymphocytes proliferative response induction, intrinsic melatonin seems to be directly involved at least in the clonal expansion of these cells. In this work, we investigated the contribution of T cells’ melatonin to regulation of the next stage of T lymphocyte activation, namely, the differentiation of T helper populations Th17 and Treg. It was shown that blockade of both membrane and nuclear melatonin receptors did not cause statistically significant changes in Th17 differentiation, although the trend was fixed for a decrease. Simultaneously, CD4+FoxP3+Т cells level decreased under the nonselective blockade of membrane hormone receptors, and Treg-associated cytokine TGF-b concentration in activated cultures supernatants decreased both in case of MT1/MT2 nonselective blockade and MT2 selective blockade. The data indicate that melatonin produced by T lymphocytes in culture can contribute to the control of naive CD4+T cell differentiation into Treg in vitro, and the hormone effects are mediated by membrane melatonin receptors. The presence of a large number targets with different affinities for melatonin in T lymphocytes determines the key role of the hormone concentration in its effects on these cells. And when interpreting data on melatonin-dependent regulation of Treg, it is important to take into account the hormone’s own production by lymphocytes, since T cells’ melatonin can mask the exogenous hormone effects or interfere with its action due to competitive binding to hormone receptors.

Effect of exogenous hormones in the expression level of OXTRs gene in cows using Rt PCR

We aimed in the current study to investigate the effect of oxytocin and prostaglandin on the expression level of the oxytocin receptor gene (OXTRs) in local Iraqi cows at postpartum period. A total of 30 local Iraqi cows were divided randomly into three groups; the first group was considered a control group. The second group was injected with oxytocin 100 IU/IM twice weekly for four weeks postpartum. The third group was injected with PGF2α at a dose of 500 µg/I.M. twice weekly for four weeks postpartum. The blood was collected twice weekly for four weeks from the jugular vein for DNA extraction and to measure the OXTRs receptor gene by real-time PCR. The current study showed that the OXTRs gene expression level was insignificant in the first week between the three groups. In the second, third, and fourth weeks, the oxytocin group showed the highest significant OXTRs expression level, followed by the progesterone group compared to the control group. In conclusion, this study provides evidence that OXTRs expression in bovine blood plasma regulates by oxytocin and prostaglandin hormones during the postpartum period.

Study on the Regulation of Exogenous Hormones on the Absorption of Elements and the Accumulation of Secondary Metabolites in the Medicinal Plant Artemisia argyi Leaves.

As an important medicinal plant, we still do not know the effect of exogenous hormones on absorption of elements and accumulation of secondary metabolites in Artemisia argyi leaves. In this work, we analyzed the difference in 21 elements absorbed by A. argyi leaves under three exogenous hormone (MeJA, SA and ABA) treatments, and also clarified the correlation between 21 elements and eight bioactive components. Different hormone treatments changed the absorption and enrichment of elements, and the composition also changed significantly. The contents of eight bioactive components changed significantly under different hormone treatments. When A. argyi was stimulated by exogenous hormones, the content of secondary metabolites was adjusted in the leaves through changes in the absorption and enrichment of elements. The widely untargeted metabolomic analysis further confirmed that ABA changes the metabolic direction of secondary metabolites in A. argyi leaves and stimulates the biosynthesis of multiple secondary metabolites including phenylpropanoids, flavonoids, terpenoids, alkaloids and others. These results provide a new perspective for the changes in element absorption and the mechanism of secondary metabolic components in A. argyi leaves under exogenous hormone treatments, and also deepen people’s understanding of the interaction mechanism between medicinal plants and hormones.

P-333 The influence of hormonal stimulation on uterine peristalsis measured by ultrasound speckle tracking in women with IVF/ICSI treatment compared to normal ovulating women

Abstract Study question To investigate possible effects of ovarian stimulation during IVF/ICSI on uterine peristalsis features using ultrasound speckle tracking compared to normal ovulating women. Summary answer Patients with a normal uterus treated with exogenous hormones during IVF/ICSI treatment show significantly increased contraction amplitude and power parameters compared to normal ovulating women. What is known already Uterine peristalsis plays a role in procreation. Subjective visual inspection of uterine peristalsis is extensively researched throughout the menstrual cycle. Studies on uterine peristalsis in IVF/ICSI patients show higher frequency of uterine contractions during the periovulatory phase. Recently, a new automated quantitative method was validated to objectively analyse uterine strain using speckle tracking. Besides objective insight in frequency, also information on amplitude, power and coordination of motion is available. The effect of exogenous hormones on uterine contraction features has not objectively been studied using this new method. Study design, size, duration This multicentre prospective observational cohort study was performed between 2020 and 2022 in the Catharina Hospital in Eindhoven, the Netherlands, Embryolab Fertility Centre in Thessaloniki, Greece and University of Naples, Federico II in Naples, Italy. 30 normal ovulating patients served as controls. The primary outcomes were the contraction features frequency, amplitude, direction, velocity, power and coordination in women undergoing IVF/ICSI on the day of follicle aspiration compared to controls on cycle day 9 – 14. Participants/materials, setting, methods 19 women undergoing IVF/ICSI were included regardless of the treatment cycle number and stimulation protocol. Indication for IVF/ICSI treatment was male subfertility (n = 8), idiopathic subfertility (n = 5), tubal factor (n = 2), primary ovarian insufficiency (n = 2) or combined (n = 2), all women had normal uteri on transvaginal ultrasound. The control group consisted of 30 healthy pre-menopausal women with normal uteri on ultrasound and spontaneous regular cycles. Main results and the role of chance Each patient underwent a 2.5 – 4 minute transvaginal ultrasound of the uterus in mid-sagittal plane. The various contraction features were extracted using a quantitative dedicated speckle tracking algorithm analysis studying motion of the subendometrial junctional zone. Mean age of IVF/ICSI patients was 32.7 years and mean BMI was 25.6. Mean age of healthy controls was 33.8 years, BMI was 23.4, and cycle length was 27.44 days. Characteristics of IVF/ICSI patients and healthy volunteers showed no statistically significant differences. Both groups predominantly consisted of nulliparous women. In IVF/ICSI patients the contraction amplitude was significantly higher compared to controls (0.062 vs 0.040; p < 0.001). The contraction power (combination of amplitude and frequency) appeared to be significantly higher in IVF/ICSI patients compared to controls (1528.18 vs 683.44; p < 0.001). No significant differences were found in contraction frequency and coordination. Even though the mean coordination did not show statistically significant differences, the values were less scattered in IVF/ICSI patients, with a much smaller range of coordination values (1.04 – 3.06) compared to healthy volunteers (1.02 – 50.33). Limitations, reasons for caution The reported difference between IVF/ICSI patients and controls in contraction amplitude and power may not solely be attributed to the administration of exogenous hormones. The difference may also be due to an underlying cause for infertility in these patients. Another limitation of this study is the small sample size. Wider implications of the findings Future research should explore which uterine contraction profile is associated with viable pregnancy: during the natural menstrual cycle, or when treated with hormones. The question arises whether it is preferred to transfer the embryo in the stimulated cycle or implement a freeze-all policy and transfer during the natural menstrual cycle. Trial registration number NCT02310802

Ewe breed differences in the cervical transcriptome at the follicular phase of a synchronised oestrous cycle

BackgroundCervical artificial insemination (AI) with frozen-thawed semen results in unacceptably low pregnancy rates internationally. The exception is in Norway, where vaginal deposition of frozen-thawed semen to a natural oestrous routinely yields pregnancy rates in excess of 70%. Previous studies by our group has demonstrated that this is due to differences in cervical sperm transport. However, a potentially important contributory factor is that ewes are inseminated to a natural oestrous in Norway but to a synchronised oestrous across most of the rest of the world. In this study, we interrogated the gene expression of the sheep cervix of four ewe breeds with known differences in pregnancy rates following cervical AI using frozen-thawed semen under the effect of exogenous hormones to synchronise the oestrous cycle. These four ewe breeds (n = 8 to 11 ewes per breed) are from two countries: Ireland (Belclare and Suffolk; medium and low fertility, respectively) and Norway (Norwegian White Sheep (NWS) and Fur; both with high fertility compared to the Irish ewe breeds).ResultsRNA extracted from cervical biopsies collected from these breeds was analysed by RNA-sequencing and differential gene expression analysis. Using the low-fertility Suffolk breed as a reference level; 27, 1827 and 2641 genes were differentially expressed in Belclare, Fur and NWS ewes, respectively (P < 0.05 and FC > 1.5). Gene ontology (GO) analysis revealed that Fur and NWS had an up-regulation of enriched pathways involved in muscle contraction and development compared to Suffolk. However, there was a down-regulation of the immune response pathway in NWS compared to Suffolk. In addition, GO analysis showed similar expression patterns involved in muscle contraction, extracellular matrix (ECM) development and cell-cell junction in both Norwegian ewe breeds, which differed to the Irish ewe breeds.ConclusionsThis novel study has identified a number of conserved and breed-specific biological processes under the effect of oestrous synchronisation that may impact cervical sperm transport during the follicular phase of the reproductive cycle.

Effects of soaking seeds with MT and EBR on germination and seedling growth in buckwheat under salt stress

<p id="C3">Soil salinization is an important limiting factor affecting seed germination, emergence, and growth of crop seeds. It is of great significance to explore the relieving effect of exogenous hormones on buckwheat seed germination and seedling growth under salt stress. This experiment was conducted to study the effects of melatonin (MT) and 2,4-epbrassinolide (EBR) on seed germination, seedling growth, antioxidant enzyme activity, and osmotic regulation substances of buckwheat varieties Xinong 9976 under different salt concentration stress using petri dish germination and pot germination. The results showed that salt stress increased the malondialdehyde (MDA) content, soluble sugar content, and antioxidant enzyme (SOD, POD, CAT) activities of buckwheat seeds and seedling leaves, decreased the germination potential, germination rate, and seedling rate of buckwheat seeds, and significantly decreased the germ length, radicle length, and seedling height of buckwheat seeds. MT and EBR soaking buckwheat seeds could effectively alleviate the harm of salt stress. Compared with the control, the germination potential, germination rate, and seedling formation rate of buckwheat seeds were increased by 14.9%-33.3%, 11.5%-27.3%, and 20.0%-46.2%, respectively. It significantly increased the radicle length, embryo length, embryo fresh weight, dry weight, seedling height, seedling fresh weight, and dry weight of buckwheat seeds, and significantly increased the soluble sugar content and the activities of SOD, POD, and CAT in buckwheat seeds and seedling leaves, and decreased MDA content. In conclusion, MT and EBR soaking can promote the germination and seedling growth of buckwheat seeds under salt stress, and improve the salt resistance of buckwheat by improving the protective enzyme activity of buckwheat seeds, reducing the accumulation of reactive oxygen species, and increasing the content of osmotic regulation substances.

Auxin-Cytokinin Balance Shapes Maize Root Architecture by Controlling Primary Root Elongation and Lateral Root Development.

The root system is responsible for water and nutrients uptake from the soil, and therefore, its extension is basic for an efficient acquisition. The maize root system is formed by different types of roots, and the lateral root branching substantially increases the surface for nutrient uptake. Therefore, the regulation of lateral root formation is fundamental in the development of root functions. Root architecture is basically controlled by auxin and cytokinins, which antagonize in the formation of lateral roots (LR) along the primary root axis, with auxin, a stimulator, and cytokinins inhibitors of LR development. This interaction has been analyzed in several zones along the primary root where LRs in different developmental stages were located. The root has been divided into several zones, such as meristem, elongation zone, and mature zone, according to the developmental processes occurring in each one. As Arabidopsis root elongated more slowly than maize root, these zones are shorter, and its delimitation is more difficult. However, these zones have previously been delimitated clearly in maize, and therefore, they analyze the effect of exogenous hormones in several LR developmental stages. The inhibitory effect of cytokinin on lateral root formation was observed in already elongated primary root zones in which initial events to form new lateral roots are taking place. Contrarily, auxin increased LR formation in the primary root segments elongated in the presence of the hormone. The inhibitory effect of cytokinin was reversed by auxin in a concentration-dependent manner when both hormones were combined. However, auxin is unable to recover LR development in primary root zones that have been previously elongated only in the presence of cytokinin. This antagonistic auxin-cytokinin effect on LR development depended on the balance between both hormones, which controls the root system architecture and determines the formation of LR during the process of initiation.

Effect of Exogenous Hormones and Reproductive Factors in Female Melanoma: A Meta-Analysis [Response to Letter

Effect of Exogenous Hormones and Reproductive Factors in Female Melanoma: A Meta-Analysis [Response to Letter

Effect of Exogenous Hormones and Reproductive Factors in Female Melanoma: A Meta-Analysis [Letter

Effect of Exogenous Hormones and Reproductive Factors in Female Melanoma: A Meta-Analysis [Letter

Effects of exogenous hormones and broodstock age on the spawning response of captive silver therapon Leiopotherapon plumbeus

Effects of exogenous hormones and broodstock age on the spawning response of captive silver therapon <i>Leiopotherapon plumbeus</i>

Sperm parameters following hormonal induction of spermiation in an endangered frog [the alpine tree frog] (Litoria verreauxii alpina).

With global amphibian biodiversity rapidly declining, improving reproductive technology outcomes has become essential. Captive breeding programs have struggled because amphibian breeding physiology often requires specific environmental cues that reproductive technologies can circumvent. This study tests the efficiency of hormonal induction by evaluating sperm quality in the endangered Litoria verreauxii alpina . We assessed the effects of exogenous hormones - gonadotrophin-releasing hormone agonist (GnRH-a, Lucrin), and human chorionic gonadotrophin (hCG, Chorulon) - on sperm quality. Hormone induction with hCG showed high efficacy while GnRH-a yielded a low response in producing sperm. Sperm quantity was affected by time post injection, with the greatest quantity at 1h post injection. Sperm quality was also affected by time, where the sperm head size decreased by 11% at 7h post injection. Based on the results from this study, we recommend that that sperm be collected soon after induction, and not more than 4h post induction in L. v. alpina . More work needs to be completed before recommending an optimal hormone induction method and dose, but 120IU of hCG per male was successful for inducing spermiation. This study represents a useful starting point for developing assisted reproductive techniques for non-model organisms.

Oral contraceptive use is not related to gender self-concept

Oral contraceptive (OC) use is a valuable and underutilized natural experiment for examining exogenous hormone effects on aspects of cognition and behavior, especially aspects that show sex or gender differences. OC use, however, is not randomly assigned; women who use OCs may systematically differ from non-users for gender-linked reasons that potentially confound investigations of the pharmacokinetic effects of OCs. Thus, the primary aim of this study was to investigate whether OC users and non-users differ in gender self-concepts, as sociocultural factors might influence who uses OCs and why. A secondary aim was to examine whether OC users of different pill formulations differ in gender self-concept. Multivariate analyses of covariance (controlling for age) on a large sample of 395 young adult women revealed no significant differences between OC users (n = 247) and non-users (n = 148) in four aspects of gender self-concept (expressivity, instrumentality, femininity, and masculinity), with univariate effect sizes averaging d = 0.07. Moreover, inferences about group differences did not change when considering sociocultural factors (i.e., reason for OC use) or pharmacokinetic properties of the pills (i.e., androgenicity). Thus, findings indicate that differences in gender self-concept do not underlie OC use and non-use, and that the androgenicity of different OC formulations does not impact gender self-concept. Taken together, findings also highlight the specificity of exogenous ovarian hormone influences, as there are documented effects on cognition but not on personal characteristics, such as gender self-concept.

Effect of exogenous salicylic acid or indole acetic acid on their endogenous levels, germination, and growth in maize

BackgroundExogenous hormone applications modify the plant growth and development by inducing changes in their endogenous contents. However, it is not clear whether the effects of exogenous hormones on growth are direct or related with changes induced in endogenous hormones. Laboratory and greenhouse experiments were conducted to study the effect of exogenous salicylic acid (SA) or indole acetic acid (IAA) on endogenous levels in soaked seeds, 5-day-old seedlings, and in vegetative growth of foliar-sprayed plants. The effects of different concentrations of two hormones on germination and growth of maize were also studied.ResultsThe effect of presoaking maize seeds in solutions of SA or IAA (0, 0.25, 0.5, 1, and 2 mM) on their endogenous contents in soaked seeds or in 5-day-old seedlings. Soaked seeds absorbed more SA than IAA. In young seedlings, the majority of two hormones which absorbed during seed soaking remained in the residual seeds. Presoaking seeds in SA or IAA solutions suppressed the growth of 5-day-old seedlings. In the greenhouse experiment, endogenous SA and IAA increased after spraying two compounds at 0.25–2 mM, peaking 2 days after treatment then decreased on. However, plants treated with SA at 1 mM or 2 mM continued to pose higher levels of endogenous SA, 8 days later. At 20 days after treatments, all tested concentrations of two hormones significantly increased the fresh and dry weights of the whole plant. These inducing effects disappeared 40 days after spraying.ConclusionThe obtained results demonstrated the changes in endogenous SA and IAA in soaked seeds, seedling, and foliar-sprayed plants due to their exogenous application. However, concentrations of two hormones did not produce any permanent enhancement effects on germination and plant growth.

Effects of exogenous plant hormones on sugar accumulation and related enzyme activities during the development of longan (Dimocarpus Longan Lour.) fruits

ABSTRACTExogenous hormone treatment is a widely used and effective method to promote fruit ripening. To our knowledge, the effects of exogenous hormones on the sugar accumulation and related enzyme activities during the development of longan fruits have not yet been elucidated. In this study, the contents of sucrose, glucose and fructose, activities and transcriptional levels of sucrose phosphate synthase (SPS), sucrose synthase (SS), acid invertase (AI) and neutral invertase (NI) were detected during fruit development of exogenous hormone-treated and non-treated longan. The results indicated that exogenous hormones (IAA, ABA, GA3) could not alter the sugar contents when fruits were ripe but accelerate the sugar accumulation. IAA and ABA increased the gene transcriptional levels and enzyme activities of SS and SPS, and also showed the tendency of increasing the transcriptional levels and enzyme activity of AI. However, GA3 decreased the gene transcriptional levels of SS and SPS, and increased the gene transcriptional level of AI. Interestingly, GA3 also increased the enzyme activity of SPS which indicated GA3 may regulate the SPS activity at post-translational levels. Our results suggested that IAA, ABA and GA3 may regulate sugar accumulation during fruit development of longan.

Hormones in Food as a Potential Risk for Human Reproductive and Health Disorders

Abstract In the last 60 years, milk, meat, and egg worldwide consumption per capita increased 2-, 3-, and 5-fold, respectively. In the same period, several studies have reported a drop of semen quality and an increased incidence of cryptorchidism, hypospadias, and some hormone-related cancers (testicular, prostate, breast, endometrial cancer) in humans. A possible reason for these disruptions is increased exposure to exogenous hormones in food of animal origin. Hormones in food are considered to affect the endocrine system and cell signaling and thus disrupt homeostasis in the consumers. Since food safety assurance is a part of the veterinary service, the risk assessment of hormones in food as potential disruptive compounds is a significant challenge. Numerous cohort and epidemiologic studies and meta-analyses have been performed with respect to find an association between the consumption of food of animal origin and particular health disorders. Additionally, several studies in animal models have been performed to explain the mechanisms of disruptive effects of exogenous hormones. Since contradictory results have been reported, there is no general conclusion about the disruptive effects of exogenous hormones. Further experiments on animals in which long-term treatment with exogenous hormones is performed and further comprehensive endocrinological, toxicological, and human epidemiological studies are needed to confirm or deny the role of exogenous hormones in human health disorders. Moreover, long-term exposure to a combination of several exogenous compounds, such as environmental pollutants and dietary hormones and their additive effects, are also not well known and should be a topic for further studies.