Detection of Progesterone Receptor as a Method of Diagnosing Mammary Cancer in Female Dogs

Introduction: Canine mammary gland tumor is the most common type of neoplasia in non-ovariectomized bitches. Approximately 50% of tumors are malignant. Neoplasms originating from the mammary gland represent the most common neoplastic disease in canines in Veterinary Medicine. Aim: Relate the expression of the receptor to progesterone (PR) with the tumor stage of canine mammary carcinoma. Material and Methods: Analytical-cross-sectional study, samples of paraffinized tumor tissue obtained from 30 canine patients with breast cancer were used. The expression of PR was performed by immunohistochemical labeling, using murine anti-PR (anti-PR Biocare brand). A descriptive analysis was carried out with the results using the SPSS program. Results: The predominant histological subtype of breast cancer was tubular carcinoma with 12 patients, followed by papillary cystic carcinoma with 6 patients, solid carcinoma 5, carcinosarcoma 4 and comedocarcinoma 3. There was a significant trend between breast cancer subtypes, histological grade G1. Among the histopathological findings, the degree of invasion is related to the presence of tumor cells in adjacent lymph nodes, which is why it is a prognostic indicator. The expression of PR in the tumor tissue samples it was 42.8% positive versus 57.14% negative, of which 75% correspond to G1, 8.3% to G2 and 16.6% to G3. With respect to the relationship of the expression of PR vs type of tumor, it was found that 50% correspond to tubular carcinoma, 33.3% to papillary cystic carcinoma, 8.3% to solid carcinoma and 8.3% to comedocarcinoma. Conclusion: The hormone receptor was negative in more than half of the patients and histological grade is significantly associated with tumor subtypes, this study emphasizes the need to introduce receptor testing into our routine clinical practice to offer the best treatment for breast cancer.

Diagnostic efficacy of virtual organ computer-assisted analysis in measuring the volume ratio of subchorionic hematoma with serum progesterone

BACKGROUND Subchorionic hematoma(SCH)is a common complication in early pregnancy characterized by the accumulation of blood between the uterine wall and the chorionic membrane.SCH can lead to adverse pregnancy outcomes such as miscarriage,preterm birth,and other complications.Early detection and accurate assessment of SCH are crucial for appropriate management and improved pregnancy outcomes.AIM To evaluate the diagnostic efficacy of virtual organ computer-assisted analysis(VOCAL)in measuring the volume ratio of SCH to gestational sac(GS)combined with serum progesterone on early pregnancy outcomes in patients with SCH.METHODS A total of 153 patients with SCH in their first-trimester pregnancies between 6 and 11 wk were enrolled.All patients were followed up until a gestational age of 20 wk.The parameters of transvaginal two-dimensional ultrasound,including the circumference of SCH(Cs),surface area of SCH(Ss),circumference of GS(Cg),and surface area of GS(Sg),and the parameters of VOCAL with transvaginal three-dimensional ultrasound,including the three-dimensional volume of SCH(3DVs)and GS(3DVg),were recorded.The size of the SCH and its ratio to the GS size(Cs/Cg,Ss/Sg,3DVs/3DVg)were recorded and compared.RESULTS Compared with those in the normal pregnancy group,the adverse pregnancy group had higher Cs/Cg,Ss/Sg,and 3DVs/3DVg ratios(P<0.05).When 3DVs/3DVg was 0.220,the highest predictive performance predicted adverse pregnancy outcomes,resulting in an AUC of 0.767,and the sensitivity,specificity were 70.2%,75%respectively.VOCAL measuring 3DVs/3DVg combined with serum progesterone gave a diagnostic AUC of 0.824 for early pregnancy outcome in SCH patients,with a high sensitivity of 82.1%and a specificity of 72.1%,which showed a significant difference between AUC.CONCLUSION VOCAL-measured 3DVs/3DVg effectively quantifies the severity of SCH,while combined serum progesterone better predicts adverse pregnancy outcomes.

Fecal progesterone and estradiol changes during the breeding season in captive female wolf

Understanding basic reproductive physiology is crucial for the management of both captive and free-ranging wolf. In the present study, we determined hormonal changes during pregnancy and the estrous cycle in captive female wolf by measuring fecal steroids collected during the breeding season with high performance liquid chromatography （HPLC）. These biochemical analyses were validated using chemical devivatization and mass spectrometry, and interpreted along with the behavioral data. All four females undergoing estrus cycles were copulated with their partners and delivered pups successfully. We found that estradiol concen-trations were significantly higher during the estrus cycle than other stages （p0.01） and progesterone was also significantly increased throughout the pregnancy （p0.01）. These hormonal fluctuations demonstrated pregnancy-specific changes in the fecal progesterone and estradiol con-centrations. Patterns of fecal estradiol and progesterone concentrations during estrous cycles were similar to those reported for other canids.

Study on prevention effect of Zishen Yutai pill combined with progesterone for threatened abortion in rats

Objective:To observe preventive and therapeutic effects and the mechanism of actions on Zishen Yutai pill combined with progesterone on threatened abortion in rats.Methods:After pregnancy,50 SPF female SD rats were selected and divided into control group,model group,progesterone group,Zishen Yutai pill group,and progesterone plus Zishen Yutai pill group(combination group),with 10 rats in each group.The rats of control group and abortion model group were lavaged with 2 mL/kg normal saline on pregnancy day 1 for continuous 10 days.Rats in Zishen Yutai pill group were given 1.575 g/kg/d of Zishen Yutai pill for intragastric administration for continuous 10 days.Rats in progesterone group were given intramuscular injection treatment of 0.1 mL/d progestin,continuous for 10 days.Rats in combination group were given injection therapy of aqueous solution of Zishen Yutai pill for continuous 10 days,and other treatments were the same as previous two groups.Abortion model were established then and live births,numbers of abortion and average rate of abortion were compared between the five groups.Peripheral blood was collected to detect the estradiol(E2) and progestational hormone(P),and obtain ratio of Th1/Th2 cytokines(IL-2,INF-γ,IL-4,IL-10).Results:Significant more live births of rats were found in the control group compared with other four groups(P<0.05).The numbers of live births of the rats in abortion model group were significantly less than that of progesterone group,Zishen Yutai pill group and joint group(P<0.05).The numbers of live births of rats in joint group were significant more than that of progesterone group and Zishen Yutai pill group.The serum E2 level of P of rats in the control group,progesterone group,Zishen Yutai pill group and joint group were significant higher than that of abortion model group(P<0.05).Serum levels of E2 and P of rats in the control group,progesterone group,Zishen Yutai pill group and joint group were not significant different(P>0.05) but these levels in the control group and Zishen Yutai pill group were significant lower than that of progesterone group and joint group(P<0.05).The maternal-fetal interface IL-4/IL-2,IL-10 / IL-2 of model group were balanced deviating to Th1,while the IL-4/IL-2,IL-10/IL-2 of progesterone group,Zishen Yutai pill group and joint group were balanced deviating to Th2,and joint group' deviation was better than progesterone group and Zishen Yutai pill group(P<0.05).Conclusions:Zishen Yutai pill combined with progesterone has a significant control effect for threatened abortion,which can obviously increase contents of maternal serums E2 and P,and regulate the Thl/Th2 balance with a remarkable effect.

Inhibitory Effect of Progesterone on Inflammatory Factors After Experimental Traumatic Brain Injury

Objective Traumatic brain injury （TBI） is one of the leading causes of morbidity and mortality in young people. Inflammatory cytokines play an important part in the pathophysiology of TBI. Recent studies demonstrate that progesterone significantly reduces cerebral edema and enhances functional recovery from TBI and stroke in several animal models. This study was designed to investigate the inhibitory effect of progesterone on inflammatory response after traumatic brain injury. Methods Progesterone was injected intraperitoneally using rats as a model of traumatic brain injury, and Western blot technique was applied to detect the expression of three inflammation-related factors： nuclear factor kappa B p65 （NFκB p65）, glial fibrillary acidic protein （GFAP）, and tumor necrosis factor-α （TNF-α）. The water content of injured brain was also examined. A neurological severity score was recorded to evaluate the effect of progesterone on neurodeficit recovery. Results NFκB p65, GFAP, and TNF-α were increased in all injured animals. In rats treated with progesterone, the expression level of NFκB p65 and TNF-α were reduced significantly in comparison with vehicle-treated rats. However, progesterone did not alter the expression of GFAP in the injured rats. Progesterone also reduced the water content of injured brain and the lesion volume. In addition, progesterone-treated injured rats showed significant improvements in the Neurological Severity Score test, compared with vehicle-treated ones. Conclusions Progesterone inhibits the inflammatory response after experimental traumatic brain injury and mitigates the severity of brain damage.

Progesterone promotes neuronal differentiation of human umbilical cord mesenchymal stem cells in culture conditions that mimic the brain microenvironment

In this study, human umbilical cord mesenchymal stem cells from full-term neonates born by vagina delivery were cultured in medium containing 150 mg/mL of brain tissue extracts from Sprague-Dawley rats （to mimic the brain microenvironment）. Immunocytochemical analysis demonstrated that the cells differentiated into neuron-like cells. To evaluate the effects of progesterone as a neurosteroid on the neuronal differentiation of human umbilical cord mesenchymal stem cells, we cultured the cells in medium containing progesterone （0.1, 1, 10 pM） in addition to brain tissue extracts. Reverse transcription-PCR and flow cytometric analysis of neuron specific enolase-positive cells revealed that the percentages of these cells increased significantly following progesterone treatment, with the optimal progesterone concentration for neuron-like differentiation being 1 tJM. These results suggest that progesterone can enhance the neuronal differentiation of human umbilical cord mesenchymal stem cells in culture medium containing brain tissue extracts to mimic the brain microenvironment.

Progesterone receptor membrane component 1 as a potential prognostic biomarker for hepatocellular carcinoma

AIM To investigate the clinicopathological significance of progesterone receptor membrane component 1(PGRMC1) and PGRMC2 in hepatocellular carcinoma(HCC). METHODS We performed immunohistochemical staining to evaluate the estrogen receptor(ER), progesterone receptor(PR), PGRMC1, and PGRMC2 in a clinical cohort consisting of 89 paired HCC and non-tumor liver samples. We also analyzed HCC data(n = 373) from The Cancer Genome Atlas(TCGA). We correlated the expression status of PGRMC1 and PGRMC2 with clinicopathological indicators and the clinical outcomes of the HCC patients. We knocked down or overexpressed PGRMC1 in HCC cell lines to evaluate its biological significance in HCC cell proliferation, differentiation, migration, and invasion. RESULTS We found that few HCC cases expressed ER(5.6%) and PR(4.5%). In contrast, most HCC cases expressed PGRMC1(89.9%) and PGRMC2(100%). PGRMC1 and PGRMC2 exhibited significantly lower expression in tumor tissue than in non-tumor tissue(P < 0.001). Lower PGRMC1 expression in HCC was significantly associated with higher serum alpha-fetoprotein expression(P = 0.004), poorer tumor differentiation(P = 0.045) and liver capsule penetration(P = 0.038). Low PGRMC1 expression was an independent predictor for worse disease-free survival(P = 0.002, HR = 2.384,CI: 1.377-4.128) in our cases, as well as in the TCGA cohort(P < 0.001, HR = 2.857, CI: 1.781-4.584). The expression of PGRMC2 did not relate to patient outcome. PGRMC1 knockdown promoted a poorly differentiated phenotype and proliferation of HCC cells in vitro, while PGRMC1 overexpression caused the opposite effects.CONCLUSION PGRMC1 is a non-classical hormonal receptor that negatively regulates hepatocarcinogenesis. PGRMC1 down-regulation is associated with progression of HCC and is a poor prognostic indicator.

Does progesterone show neuroprotective effects on traumatic brain injury through increasing phosphorylation of Akt in the hippocampus?

There are currently no federally approved neuroprotective agents to treat traumatic brain injury. Progesterone, a hydrophobic steroid hormone, has been shown in recent studies to exhibit neu-roprotective effects in controlled cortical impact rat models. Akt is a protein kinase known to play a role in cell signaling pathways that reduce edema, inlfammation, apoptosis, and promote cell growth in the brain. This study aims to determine if progesterone modulates the phosphor-ylation of Aktvia its threonine 308 phosphorylation site. Phosphorylation at the threonine 308 site is one of several sites responsible for activating Akt and enabling the protein kinase to carry out its neuroprotective effects. To assess the effects of progesterone on Akt phosphorylation, C57BL/6 mice were treated with progesterone （8 mg/kg） at 1 （intraperitonally）, 6, 24, and 48 hours （subcutaneously） post closed-skull traumatic brain injury. The hippocampus was harvest-ed at 72 hours post injury and prepared for western blot analysis. Traumatic brain injury caused a signiifcant decrease in Akt phosphorylation compared to sham operation. However, mice treat-ed with progesterone following traumatic brain injury had an increase in phosphorylation of Akt compared to traumatic brain injury vehicle. Our ifndings suggest that progesterone is a viable treatment option for activating neuroprotective pathways after traumatic brain injury.

Distribution and Accumulation of Neodymium and Its Effect on Secretion of Progesterone in Mice

Distribution and accumulation of Nd, and its effect on secretion of progesterone in mice were studied using radioisotope tracer ((()^(147)Nd)) technique. Following single intraperitoneal administration of neodymium traced with (()^(147)Nd) at a dose of 200 mg·kg^(-1), uneven distribution of the radioactive Nd occurred in various tissues and organs. Much amount of (()^(147)Nd) accumulates in the bone, and the residue increases with the lapse of time. Some amount of radioactivity was also detected in eyes, blood and brain, but the accumulation decreased with the time due to excretion and re-distribution in mice. In comparison with controls, concentration of progesterone is found to be significantly lower in the serum of administered mice, indicating a significantly inhibitory effect of Nd on secretion of progesterone.

Human sperm pattern of movement during chemotactic ＇e-orientation towards a progesterone source

Human spermatozoa may chemotactically find out the egg by following an increasing gradient of attractant molecules. Although human spermatozoa have been observed to show several of the physiological characteristics of chemotaxis, the chemotactic pattern of movement has not been easy to describe. However, it is apparent that chemotactic cells may be identified while returning to the attractant source. This study characterizes the pattern of movement of human spermatozoa during chemotactic re-orientation towards a progesterone source, which is a physiological attractant candidate. By means of videomicroscopy and image analysis, a chemotactic pattern of movement was identified as the spermatozoon returned towards the source of a chemotactic concentration of progesterone （10 pmol I^-1）. First, as a continuation of its original path, the spermatozoon swims away from the progesterone source with linear movement and then turns back with a transitional movement that can be characterized by an increased velocity and decreased linearity. This sperm behaviour may help the spermatozoon to re-orient itself towards a progesterone source and may be used to identify the few cells that are undergoing chemotaxis at a given time.

The Nongenomic Effects of Progesterone in Repressing iNOS Activation through P38MAPK Pathways in Gonococci-Infected Polymorphonuclear Leukocytes and the Clinical Significance

Progesterone has nongenomic effects on inducible nitric oxide synthase(iNOS),which is mediated by mitogen activated protein kinase(MAPK)pathways.This effect is supposed to have some potential association with asymptomatic gonococcal infections in women by immunological depression.In this study,polymorphonuclear leukocytes(PMNs)challenged by gonococci were used to study the nongenomic effects of progesterone.The activation of iNOS was assessed by measuring [3H] L-arginine converses to [3H] L-citrulline,and t...

Effects of estradiol and progesterone on the proinflammatory cytokine production by mononuclear cells from patients with chronic hepatitis C

AIM:To investigate the effects of estradiol (E2) and progesterone on the unstimulated and oxidative stressstimulated production of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-8, and macrophage chemotactic protein (MCP)-1 by peripheral blood mononuclear cells (PBMCs) from patients with chronic hepatitis C and healthy controls. METHODS:The PBMCs were separated from agematched 72 males and 71 females with and without chronic hepatitis C, who were divided into two groups based on a mean menopausal age of 50 years. Oxidative stress was induced by hydrogen peroxide in the cells incubated in serum-free media. Cytokines in the culture supernatant were measured by an enzyme-linked immunosorbent assay. RESULTS:The highest levels of the spontaneous production of TNF-α, IL-1β, IL-8, and MCP-1 by the unstimulated PBMCs were in the older male patients with chronic hepatitis C and the lowest levels were in the premenopausal female healthy controls. E2 inhibited the cytokine production by the unstimulated PBMCs from the older male and post-menopausal female patients, which was further stimulated by progesterone. The exposure to hydrogen peroxide in the PBMCs from the younger male and pre-menopausal female healthy subjects induced the production of cytokines. The change rates of the hydrogen peroxide-stimulated cytokine production were suppressed by E2 and enhanced by progesterone. CONCLUSION:These findings suggest that E2 may play a favorable role in the course of persistent liver injury by preventing the accumulation of monocytes-macrophages and by inhibiting proinflammatory cytokine production, whereas progesterone may counteract the favorable E2 effects.

Progesterone effects on the oligodendrocyte linage: all roads lead to the progesterone receptor

A new role has emerged for progesterone after discovering its potent actions away from reproduction in both the central and the peripheral nervous system. The aim of the present report is to discuss progesterone’s mechanisms of action involved in myelination, remyelination and neuroinflammation. The pivotal role of the classic progesterone receptor is described and evidence is compiled about progesterone’s direct effects on oligodendrocyte linage and its indirect effects on oligodendrocyte precursor cell differentiation by decreasing the neuroinflammatory environment.

Routine Progesterone Supplementation in Threatened Abortion: Is It a Sound Practice?

Aim: To evaluate the benefits and hazards of routine progesterone supplementation in threatened abortion and whether it is a sound practice or not. Materials and Methods: This study was conducted at Obstetrics and Gynecology Department, Tanta University in the period from January 2018 to December 2018. Eligible patients (n = 190) were randomly allocated into 2 groups: study group who will receive progesterone supplementation (prog. group) and control group who will receive no treatment (place. group). Results: No significant differences were found between both groups regarding all demographic data and pregnancy characteristics. Abortions were higher in place. group 17 (23.94%) than in prog. group 12 (16.44%) with no significant difference p value = 0.263. The incidence of preterm labour was also higher in the place. group 22 (30.99%) in comparison to the prog. group 17 (23.29%) with no significant difference p value = 0.300. Conclusion: Progesterone supplementation in threatened abortion was not beneficial although it reduced abortion and preterm labour rates.

The Effect of GnRHa Induced Superovulation on Endometrial Morphology and Estrogen Receptor and Progesterone Receptor in Mouse

To evaluate the effect of GnRHa induced superovulation protocol on endometrial morphology and function. Material & Methods Forty ICR mice were randomly allocated into 4 groups, among them, 2 experimental groups were injected with GnRHa+HMG+hCG, another 2 groups were given saline of same volume as control group. The uterine tissues were investigated at 24 h and 48 h after administration (experimental group) or ovulation (control group).The endometrial thickness, the size of gland and glandular lumen, the total area of glandular cells, the average height of glandular epithelium were measured from routine histological slides using computerized image analysis. The SP immunohistochemistry techniques with monoclonal antibodies were employed to semi quantitatively analize the estrogen receptor (ER) and progesterone receptor (PR) in glandular cells. Results The endometrial thickness was not significantly different between experimental groups and control groups at 24 h and 48 h (P>0.05).The average area, perimeter, maximal diameter of single gland and glandular lumen, the total area, average height of glandular epithelium in experimental groups were significantly smaller than those of in control groups at equivalent time stages (all P<0.01). The asynchronous development of gland epithelium and stroma cells, namely, pesudostratified glandular epithelium and predecidual changes of stroma cells were seen at same time in experimental groups. The positive percentage (%) and expression intense of ER and PR in glandular epithelium cells were significantly lower in experimental groups than in control groups (P<0.05). Conclusion The protocol with GnRHa had a negative effect on endometrial histological structure and down regulated the express of ER and PR, suggesting that this protocol effect on the endometrial morphology and function and could not facilitate the formation of a physiologic endometrium completely, which may be one of the causes of low pregnancy rates.

Give progesterone a chance

There is currently no standard pharmacological treatment for spinal cord injury. Here, we suggest that progesterone, a steroid hormone, may be a promising therapeutical candidate as it is already for traumatic brain injury, where it has reached phase II clinical trials. We rely on previous works showing anti-inflammatory, neuroprotective and promyelinating roles for progesterone after spinal cord injury and in our recent paper, in which we demonstrate that progesterone diminishes lesion, preserves white matter integrity and improves locomotor recovery in a clinically relevant model of spinal cord lesion.

Effect of vitamin D3 on production of progesterone in porcine granulosa cells by regulation of steroidogenic enzymes

1,25-dihydroxyvitamin D3 （VD3）, an active form of Vitamin D, is photosynthesized in the skin of vertebrates in response to solar ultraviolet B radiation （UV-B）. VD3 deficiency can cause health problems such as immune disease, metabolic disease, and bone disorders. It has also been demonstrated that VD3 is involved in reproductive functions. Female sex hormones such as estrogen and progesterone are biosynthesized mainly in ovarian granulosa cells as the ovarian follicle develops. The functions of sex hormones include regulation of the estrus cycle and puberty as well as maintenance of pregnancy in females. In this study, we isolated granulosa cells from porcine ovaries and cultured them for experiments. To examine the effects of VD3 on ovarian granulosa cells, the mRNA and protein levels of genes were analyzed by Real-time PCR and Western blotting assay. Production of progesterone from granulosa cells was also measured by ELISA assay. As a result, transcriptional and translational regulation of progesterone biosynthesis-related genes in granulosa cells was significantly altered by VD3. Furthermore, progesterone concen- trations in porcine granulosa cell-cultured media decreased in response to VD3. These results show that VD3 was a strong regulator of sex steroid hormone production in porcine granulosa cells, suggesting that vitamin D deficiency may result in inappropriate sexual development of industrial animals and eventually economic loss.

Effects of coriaria lactone-activated,astrocyte-conditioned medium on estrogen receptor and progesterone receptor expression in rat cortical and hippocampal neurons

BACKGROUND： Coriaria lactone-activated astrocytes released bioactive substances that eventually caused epilepsy. OBJECTIVE： It has been suggested that activated astrocytes alter the expression of the estrogen receptor and progesterone receptor by releasing bioactive substances during epilepsy, thereby affecting neuronal activity in the brain. This study was designed to observe the expression of the estrogen receptor and the progesterone receptor in rat brain following lateral ventricle injection of coriaria lactone-activated, astrocyte-conditioned medium. DESIGN AND SETTING： This immunohistochemical, randomized, controlled, animal study was conducted at the Department of Pathology, Hospital Affiliated to Binzhou Medical College, China. MATERIAL： Coriaria lactone was provided by Huaxi Pharmaceutical Factory, China. METHODS： Forty adult, healthy, male, Sprague Dawley rats were randomly assigned into two groups. Astrocyte-conditioned medium （10 μ L） was injected into rat lateral ventricle in the control group （n = 8）. Coriaria lactone-activated, astrocyte-conditioned medium （10 μL） was infused into the rat lateral ventricle in the coriaria lactone group （n = 32）. At 2, 4, 8 and 12 hours following injection, rats were sacrificed and subjected to immunohistochemistry. Eight rats were studied at each time point. MAIN OUTCOME MEASURES： Behavioral changes were observed in rats of both groups. Expression of the estrogen receptor and the progesterone receptor in rat cortical and hippocampal neurons was measured using immunohistochemistry. RESULTS： Four hours after injection, estrogen receptor levels in rat cortical and hippocampal neurons were significantly higher in the coriaria lactone group than in the control group （P 〈 0.05）. Progesterone receptor levels were significantly lower in the coriaria lactone group than in the control group （P 〈 0.05）. Seizures were not observed in the control group. In the coriaria lactone group, convulsions appeared 30 minutes after injection; seizures reached grade Ⅲ at 45 minutes rat behavior was nearly normal at 2 hours. CONCLUSION： Activated astrocytes can induce seizures in the rat by enhancing estrogen receptor expression and decreasing progesterone receptor expression in cerebral cortical and hippocampal neurons.

Selective Expression of Progesterone Receptor in Malignant Melanoma Was Inversely Correlated with PCNA

To investigate the role of progesterone receptor （PR） expression in malignant melanoma （MM）, PR and proliferative cell nuclear antigen （PCNA） expression were immunohistochemistrically evaluated in a series of 35 specimens of MM, and the correlation between the immunohistochemistrical findings and clinicopathological data was also analyzed. PR expression was detected in 25.7% （9/35） of the patients with MM. No PR expression was observed in nevi. PR expression was inversely correlated with PCNA expression （r=-0.353, P=-0.026）. PR expression was slightly increased in females, subjects aged under 55 y, those with ulceration, non-acral subtype and diagnosis delay longer than 1 y, but the difference was not statistically significant. Selective expression of progesterone receptor in malignant melanoma might be correlated with inhibited tumor growth.

Establishment and Optimization of HPLC-MS/MS for Detection of Progesterone Residue in Raw Milk

In order to establish an HPLC-MS/MS method for detecting progesterone in raw milk,raw milk was extracted with methanol,and then determined by HPLC-MS/MS after the purification with a C18 solid phase extraction column. Qualitative determination was performed according to retention time and selective ion abundance ratio,and quantification was performed by external standard method. The results showed that progesterone had a good linear relation in the range of0. 1-5. 0 ng/ml,with a correlation coefficient of 0. 999 9. The detection limit of the established method was 0. 02 μg/kg,and the quantification limit was0. 04 μg/kg. In the standard addition range of 0. 1-5. 0 ng/ml,the recovery ranged from 79. 6% to 105. 1%,with relative standard deviation≤8. 9%. Compared with the industry standard,the detection limit and the quantification limit of the established method are significantly reduced,and the sensitivity of the method is enhanced,so this method is suitable for the detection of progesterone residue in fresh milk in pastures.