Excess body weight and risk of first-ever acute ischaemic non-embolic stroke in elderly subjects.

In a population-based case-control study we assessed the association between obesity and acute ischaemic/non-embolic stroke. A total of 163 patients aged older than 70 years (88 men and 75 women) admitted due to a first-ever-in-a-lifetime acute ischaemic/non-embolic stroke and 166 volunteers (87 men and 79 women) without a history of cardiovascular disease were included. The association of stroke with body mass index (BMI) or waist circumference (WC) was determined by multivariate logistic regression modelling after adjusting for potential confounding factors. Overweight and obesity were more prevalent amongst stroke patients compared to controls. Subjects with a BMI > or = 30 kg/m2 had 2.5-times higher odds to suffer an acute ischaemic/non-embolic stroke compared to subjects within the lowest BMI category of 18.5-20.9 kg/m2. Analysis of interaction showed that in the presence of overweight and/or obesity (classified as a BMI > or = 25 kg/m2 and/or a WC > 102 cm in men and > 88 cm in women) the inverse relationship between HDL cholesterol and ischaemic/non-embolic stroke was negated. Excess weight is associated with an increased risk of acute ischaemic/non-embolic stroke in elderly individuals independently of concurrent metabolic derangements. Moreover, in the presence of obesity, HDL cholesterol loses its protective effect against ischaemic stroke.

Diarrheic shellfish poisoning due to toxic mussel consumption: the first recorded outbreak in Greece.

During the week of 14-20 January 2000, 120 people visited the Emergency Departments of hospitals in Thessaloniki, northern Greece, complaining of acute gastrointestinal illness after eating mussels (Mytilus galloprovincialis). The symptoms indicated diarrhoeic shellfish poisoning, and the toxicity of mussels harvested from Thermaikos Gulf in Thessaloniki during the outbreak was investigated using mouse bioassays. The bioassays revealed toxicity to mice by the mussel samples; while high numbers of toxic algae Dinophysis acuminata were identified in water samples from Thermaikos Gulf. The harvesting of mussels was immediately suspended and a monitoring programme for algal blooms was established from then onwards. During a follow-up of the mussels' toxicity from January 2000 to January 2005, two more mussel samples were found positive for diarrheic shellfish poisoning: one harvested in March 2001 from the area of the outbreak (Thermaikos Gulf) and the other harvested in January 2001 from Amvrakikos Gulf in north-western Greece. However, no sporadic cases or outbreaks were reported during this period.

Serum uric acid levels and risk for acute ischaemic non-embolic stroke in elderly subjects.

BACKGROUND: Elevated serum uric acid (SUA) levels have been proposed as an independent risk factor for cardiovascular (CV) morbidity and mortality. Recent evidence suggests that treatments with a hypouricaemic action have a favourable effect on CV event prevention. OBJECTIVES: The association between SUA and acute ischaemic/non-embolic stroke was assessed in a population-based case-control study in the prefecture of Ioannina, Epirus, Greece. SUBJECTS AND METHODS: A total of 163 patients aged older than 70 years (88 men and 75 women) admitted due to a first-ever-in-a-lifetime acute ischaemic/non-embolic stroke and 166 volunteers (87 men and 79 women) without a history of CV disease were included. The association between SUA and stroke was determined by multivariate logistic regression modelling after adjusting for potential confounding factors. RESULTS: Stroke patients showed higher concentrations of SUA compared with controls (333.1+/-101.1 micromol L(-1) vs. 285.5+/-83.3 micromol L(-1); P<0.001). In univariate analysis elevated SUA levels were associated with increased risk for ischaemic stroke [odds ratio (OR) 1.42, 95% confidence interval (CI) 1.21-1.64, P<0.0001]. Compared to patients with SUA levels in the lowest quintile, those within the highest quintile had a 2.8-time increase in the odds of suffering an ischaemic stroke (OR 2.81, 95% CI 1.67-4.73, P<0.001). This association was strong even after controlling for gender, age, body mass index, the presence of hypertension and diabetes mellitus, drug treatment and lipids (OR 2.90, 95% CI 1.59-5.30, P=0.001). CONCLUSION: Elevated SUA is associated with an increased risk for acute ischaemic/non-embolic stroke in a strictly defined population of elderly individuals independently of concurrent metabolic derangements. This association may need to be considered when treating the elderly.

Serum leptin and erythropoietin during menstruation.

OBJECTIVE: The potential influence of leptin and erythropoietin on the angiogenesis and bleeding of the endometrium during normal menstrual cycles and possible correlations between them. STUDY DESIGN: Serum concentrations of leptin and erythopoietin were measured at menstrual days 20, 1 and 3 or 4 in healthy, non-obese, normal menstruating women. RESULTS: Mean leptin and erythropoietin concentrations showed no significant alteration over time (F = 0.588, p = 0.563 and F = 0.654, p = 0.528, respectively). There was, however, a strong negative linear relationship between the concentration of the two substances on days 1 and 3 or 4 (p = 0.018 and p = 0.028, respectively). CONCLUSIONS: If the two substances affect endometrial angiogenesis, they may do this in a locally limited way, so that peripheral concentration changes cannot be observed. Their inverse correlation prompts further study with receptor determination.

Relation between leptin and cortisol values in umbilical vessels at normal vaginal delivery.

To study the role of various hormones in the control of fetal leptin secretion during labour, 33 pregnant women with normal singleton term pregnancy were recruited. At the time of spontaneous vaginal delivery, a venous blood sample was taken from the women together with a venous and an arterial cord blood sample. In all blood samples, leptin, cortisol, prolactin and progesterone were measured. Serum leptin and cortisol values were significantly higher, while those of prolactin and progesterone were significantly lower in the mother than in the two umbilical vessels (p < 0.01). Cortisol levels were significantly higher in the umbilical artery than in the umbilical vein (p < 0.01). Serum leptin values in the umbilical artery and vein correlated significantly with the corresponding values of cortisol (r = 0.523 and r = 0.580 respectively, p < 0.01), but not with those of prolactin and progesterone. A weak but significant correlation was found between leptin values in the two umbilical vessels and birth weight (r = 0.385 and r = 0.401 respectively, p < 0.05). In multiple regression analysis, cortisol values but not birth weight was the most important determinant of leptin values. Birth weight, however, correlated significantly with placental weight (r = 0.776, p < 0.001). These results demonstrate for the first time that leptin concentrations in the umbilical vessels at normal vaginal delivery correlate significantly with cortisol values, thus providing evidence that cortisol mediates a labour stimulating effect on fetal leptin secretion. It is suggested that cord blood leptin values at delivery are not a good predictor of neonatal weight.

Absence of leptin expression and secretion by human luteinized granulosa cells.

Whether leptin is secreted by the human ovary is not known. The available data on leptin gene (ob gene) expression by human granulosa cells are conflicting. The aim of the present study was first to re-examine the expression of leptin messenger RNA (mRNA) by human granulosa cells and second to investigate if these cells have the ability to secrete leptin in cultures. Human luteinized granulosa cells were obtained from normal women undergoing in vitro fertilisation treatment after ovarian stimulation and follicle aspiration. The expression of ob gene was studied by Reverse-Transcriptase Polymerase Chain Reaction (RT-PCR) both in primary granulosa cells treated immediately after oocyte recovery and in cells cultured up to 24 h under baseline and hormonally stimulated conditions (FSH: 100 ng/ml, LH: 100 ng/ml). ob mRNA transcripts were not detected in luteinized granulosa cells, while they were present in adipose tIssue cDNA. Actin gene expression was detected in all studied samples. Using a sensitive radioimmunoassay (lower limit of detection 0.05 ng/ml), leptin was undetectable in the culture media at all points during the 72 h cultures, while at the same time significant amounts of oestradiol and progesterone were produced particularly after the addition of androstendione (1 microM) to the incubation media. These results demonstrate for the first time that leptin is not secreted by human luteinized granulosa cells in cultures. From a physiological point of view, this may contribute to the development of the optimal follicular environment for oocyte maturation during the preovulatory period.

Routine differential diagnosis of proteinurias by capillary electrophoresis.

Capillary electrophoresis is a relatively new analytical technique that begins to have an impact on both routine and research in clinical laboratories. Recently, a fully automated system has become commercially available (Paragon CZE 2000, Beckman, USA) for the analysis of human serum proteins. Urine protein analysis, on the other hand, is currently accomplished by electrophoresis of concentrated urine specimens. The method is used to distinguish the glomerular from the tubular proteinuria and for the identification of Bence-Jones proteins. The procedure is labor-intensive and technically demanding. We developed a technique for the serum capillary electrophoresis instrument that can also be applied routinely to the differential diagnosis of proteinurias. Overriding the programmed dilution step of the instrument, we were able to distinguish different types of proteinurias without concentration of specimens with a total protein content of 150-200 mg/l as determined by sulfosalicylic acid. The different electrophoretic patterns obtained by the capillary electrophoresis system for various specimens correlated well with established techniques (Hydragel Proteinurie Kit, Sebia, France). The method is applicable for routine analysis of urinary proteins. It is reliable, less expensive and faster than the conventional methods (electrophoretic or immunonephelometric) used today for the differentiation of proteinurias, and it can be used as a quick screening test.

Oestradiol plus progesterone treatment increases serum leptin concentrations in normal women.

BACKGROUND: Previous studies have alluded to a role for both oestradiol and progesterone in the secretion of leptin from fat cells in the human, although direct evidence has yet to be obtained. The study aim was to assess serum leptin concentrations in normally cycling women receiving exogenous oestradiol and progesterone. METHODS: Normally cycling women were investigated in an untreated spontaneous cycle (control, n = 10), a cycle treated with oestradiol (oestradiol cycle, n = 10) and a cycle treated with oestradiol plus progesterone (oestradiol+progesterone cycle, n = 6). Oestradiol was given to the women through skin patches on cycle days 2, 3 and 4, and progesterone intravaginally on cycle days 3, 4 and 5. Serum concentrations of leptin, oestradiol, progesterone, FSH and LH were measured in daily blood samples. RESULTS: During the treatment, serum oestradiol and progesterone concentrations increased significantly. In the oestradiol cycles, leptin concentrations were not affected by treatment and did not differ from those in controls. In the oestradiol+progesterone cycles, leptin concentrations (mean +/- SEM) increased in all women from cycle day 3 (8.6 +/- 1.1 ng/ml) to days 5 (12.2 +/- 1.8 ng/ml, P < 0.01) and 6 (11.9 +/- 2.0, P < 0.05), and were at these points significantly higher than in the control cycles (P < 0.05). The mean percentage increase from day 3 to the peak concentration on days 5 or 6 was 62.6 +/- 6.8%. Leptin concentrations returned to the pretreatment value on day 7, together with the concentrations of oestradiol and progesterone. In the oestradiol+progesterone cycles, leptin concentrations correlated significantly with oestradiol and progesterone concentrations, but not with FSH and LH concentrations. CONCLUSIONS: These results show, for the first time, that leptin secretion can be stimulated in women by the administration of oestradiol plus progesterone. This may explain the increased concentrations of leptin during the luteal phase of the normal menstrual cycle.

Treatment of normal women with oestradiol plus progesterone prevents the decrease of leptin concentrations induced by ovariectomy.

To study the role of oestradiol and progesterone in the secretion of leptin, 21 normally ovulating women were recruited from those scheduled for ovariectomy plus hysterectomy performed in mid-follicular phase of the cycle. Seven of the women were used as controls and received no hormonal treatment post-operatively. Another seven women received oestradiol (oestradiol group) and the remaining seven women received oestradiol plus progesterone (oestradiol plus progesterone group). Serum leptin values showed a temporal but significant increase 24 h after the operation and were significantly correlated with the cortisol and progesterone values, which increased temporarily at 12 h. At that time a marked decline in oestradiol concentrations was seen. After the temporal increase, leptin values in the controls and the oestradiol group decreased significantly up to day 4 (P: < 0.05), while in the oestradiol plus progesterone group they increased (P: < 0.01) and were significantly higher than in the other two groups (P: < 0.05). Body mass index (BMI) was the most important variable accounting for the changes in leptin values post-operatively, but in the oestradiol plus progesterone group progesterone correlated significantly with leptin independently of BMI. These results suggest that progesterone and cortisol can stimulate leptin secretion in women regardless of oestradiol concentrations.

The effect of thyrotoxicosis on adrenocortical reserve.

OBJECTIVE: Variations in thyroid function are known to be associated with changes in adrenocortical activity. Previous studies in animals have suggested that long-standing hyperthyroidism may be associated with diminished adrenal functional reserve despite a continuing hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis. In humans, there has been no direct assessment of adrenal secretory reserve in clinical thyrotoxicosis. This study aimed to assess adrenocortical reserve in response to low-dose ACTH, following dexamethasone suppression, in patients with severe thyrotoxicosis. DESIGN AND METHODS: Ten patients (four men and six women, 30-45 years) with severe long-standing thyrotoxicosis due to Graves' disease (n=6) or toxic nodular goitre (n=4) were studied at diagnosis and again when in a stable euthyroid state following drug therapy for 8-12 months. All patients underwent ACTH stimulation tests at 0800h with ACTH(1-24) (Cortrosyn; 0.1microg/kg body weight, i.v.) following overnight suppression of the HPA axis with dexamethasone (1mg per os at 2300h). Serum cortisol was assayed at -15, 0, 15, 30, 60 and 90min after the administration of ACTH. RESULTS: The mean (+/-s.d.) peak and delta cortisol responses to ACTH (634.5+/-164nmol/l and 618+/- 196nmol/l respectively), as well as the net area under the response curve (36769+/-12188nmol/lx min) in the hyperthyroid patients were significantly lower compared with the values when the same patients were euthyroid (911+/-157nmol/l, 905+/-160nmol/l and 57652+/-10128nmol/lxmin respectively; P<0.005). Subnormal peak cortisol responses (<500nmol/l) were observed in two severely toxic patients. The findings were independent of the cause of thyrotoxicosis. CONCLUSION: In patients with severe thyrotoxicosis, cortisol secretion in response to low-dose ACTH stimulation, following dexamethasone suppression, is lower in the hyperthyroid than in the euthyroid state. It appears that thyrotoxicosis is associated with subtle impairment of adrenocortical reserve.

Growth hormone response to thyrotrophin releasing hormone in women with polycystic ovarian syndrome.

Recent clinical studies have suggested that women with polycystic ovarian syndrome (PCOS) may have disturbances of growth hormone (GH) kinetics and the GH/insulin-like growth factor (IGF)-I system. The knowledge that in various metabolic abnormalities there is a paradoxical sensitivity of pituitary somatotrophs to thyrotrophin releasing hormone (TRH) administration led to this investigation of the GH secretory response to TRH in women with PCOS. Twenty-four women with PCOS and 18 control women were studied. TRH was given as a single i.v. injection (time 0) and blood samples for GH measurements were obtained at -15, 0, 15, 30, 60 and 90 min. The GH responses were expressed as the area under the curve (AUC) or the differences from the basal value (Deltamax). The GH response to TRH (mean +/- SEM) was greater in women with PCOS (Deltamax 2.47 +/- 1. 73 versus 0.47 +/- 0.06 ng/ml, P < 0.05 and GH AUC 8.05 +/- 2.10 versus 2.58 +/- 0.18 ng/ml/90 min, P < 0.05). According to GH response to TRH, two PCOS subgroups were identified: (i) normal responders (n = 14) who showed Deltamax GH response (0.36 +/- 0.06 ng/ml)and GH AUC (1.93 +/- 0.64 ng/ml/90 min) similar to that in the controls and (ii) over-responders (n +/- 10) who showed a paradoxical increase in GH concentrations in response to TRH (Deltamax GH response 5.43 +/- 1.27 ng/ml and GH AUC 16.62 +/- 3.51 ng/ml per 90 min) that was significantly higher than in normally responding PCOS patients (P < 0.0001) or in controls (P < 0.0001). These data demonstrate an enhanced GH response to TRH administration in a subgroup of women with PCOS.

Role of cytokines in the pathogenesis of anemia of chronic disease in rheumatoid arthritis.

The aim of our study was to evaluate the role of proinflammatory cytokines: tumor necrosis factor alpha (TNFalpha), interleukin-1beta (IL-1beta), and interleukin-6 (IL-6), as well as the possible contribution of interleukin-10 (IL-10) in anemia of chronic disease (ACD) of rheumatoid arthritis (RA) patients. We measured the serum levels of TNFalpha, IL-1beta, and IL-6 in 105 anemic and 127 nonanemic RA patients. We also investigated the effects of the above cytokines on the development of burst-forming units-erythroid (BFUe) and colony-forming units-erythroid (CFUe) in bone marrow cultures. Anemic patients had significantly higher serum levels of TNFalpha, IL-1beta, and IL-6 compared to nonanemics. Serum IL-10 levels were low and there was no significant difference in IL-10 concentrations between anemic and nonanemic patients. Proinflammatory cytokines inhibited proliferation of BFUe and CFUe. IL-10 did not decrease the erythroid colony growth. Proinflammatory cytokines may play a role in the pathogenesis of ACD in RA patients. Low levels of IL-10 possibly contribute to the development of ACD.

Study of growth hormone secretion and action in growth-retarded children with juvenile chronic arthritis (JCA).

The stimulated and spontaneous growth hormone (GH) secretion and the response to GH action were assessed in growth-retarded children with juvenile chronic arthritis (JCA), in order to determine the underlying mechanisms of growth retardation in such children. Six children (4 boys and 2 girls aged 10.7-13.8 years) with active JCA of systemic onset were included in the study which involved: (1) anthropometric measurements; (2) assessment of GH responses to insulin-induced hypoglycaemia and clonidine stimulation; (3) assessment of the nocturnal pulsatile GH secretion by measuring GH in blood samples obtained every 20 min from 20.00 to 08.00 h; and (4) the IGF-I generation test. As a control, the latter test was also performed in eight aged-matched children with physiological delay in puberty. Biosynthetic hGH (0.1 IU/kg BW) was administered s. c. for 4 days and blood samples were taken at baseline and the morning after the last GH injection for measurement of IGF-I and IGFBP-3. All six children with JCA were prepubertal and their growth velocity was <3 cm/year. The GH responses to both stimulation tests were normal (peak GH >20 mU/l). Analysis of the pulsatile GH secretion during the night revealed three-to-four GH pulses of normal amplitude (>20 mU/l). IGF-I (26.7+/-4.6 nmol/l, mean+/-SD) and IGFBP-3 (2.1+/-0.2 mg/l) levels were lower in the patients compared with the controls (43.0+/-3.7 nmol/l and 2.8+/-0.2 mg/l, respectively, P<0.01). Following stimulation with exogenous hGH, there was a significant increase in IGF-I and IGFBP-3 levels in the control group (85 and 73%, respectively), but only a small increase in the patients (31 and 14%). It appears that stimulated and spontaneous GH secretion is normal in children with active systemic JCA, but the response to endogenous and exogenous GH with regard to IGF-I and IGFBP-3 production is impaired, indicating a degree of GH insensitivity in such children.

Purification of a candidate gonadotrophin surge attenuating factor from human follicular fluid.

Gonadotrophin surge attenuating factor (GnSAF) is a new non-steroidal ovarian substance, different from inhibin, which attenuates the pre-ovulatory luteinizing hormone (LH) surge in superovulated women. Human follicular fluid (FF) was used as a source for the isolation of GnSAF, the activity of which was monitored in an in-vitro pituitary bioassay. Primary rat pituitary cells were incubated with test substances for 48 h and subsequently washed and incubated with 0.1 micromol/l gonadotrophin releasing hormone (GnRH) plus test substances for 4 h. GnSAF activity was expressed as the reduction of GnRH-induced LH secretion in the 4 h incubation. GnSAF was purified from 250 ml of FF which was heat-treated at 80 degrees C for 5 min. Heparin-sepharose chromatography, Con-A sepharose chromatography, reversed-phase high-performance liquid chromatography (HPLC) and preparative native gel electrophoresis were used for GnSAF fractionation. Using these purification steps, we have obtained an apparently homogeneous preparation that stains as a single band on sodium dodecyl sulphate (SDS)-polyacrylamide gel electrophoresis. GnSAF has an apparent molecular weight of 12.5 kDa and was identified by amino acid sequence (mass spectrometry) to be the C-terminal fragment of human serum albumin.

Leptin concentrations in normal women following bilateral ovariectomy.

To study the relationships between gonadal steroids and leptin, 20 women with normal cycles were investigated during the postoperative period following a laparotomy. Fourteen women underwent bilateral ovariectomy plus total hysterectomy either in the mid- to late follicular phase (n = 7, group 1) or in the early to midluteal phase (n = 7, group 2). The remaining six of the 20 women underwent cholocystectomy in the early to midfollicular phase of the cycle and were used as controls (group 3). In all three groups, serum leptin values decreased rapidly up to post-operative day 4. Then, leptin values increased significantly only in group 3 (P < 0.05). Leptin values before and after the operation showed significant positive correlations with body mass index (BMI), oestradiol and progesterone. However, with multiple regression analysis, BMI was the only parameter significantly correlated with leptin in group 3 (days 0 and 4-7), whereas in groups 1 and 2 progesterone and BMI showed independent significant correlations with leptin (days 0 and 8, r = 0.601 and r = 0.602 respectively). These results demonstrate for the first time a significant reduction in leptin concentrations in normal women following bilateral ovariectomy. Although BMI seems to be the predominant factor, it is also suggested that oestradiol and progesterone may participate in the control of leptin production during the human menstrual cycle.

Thyroid autoimmunity is associated with higher urinary iodine concentrations in an iodine-deficient area of Northwestern Greece.

Northwestern Greece was identified in the 1960s for its high prevalence of endemic goiter and iodine deficiency. Although iodized salt has been commercially available since then, a recent epidemiological survey of 3916 schoolchildren found that low-grade goiter is still prevalent in endemic proportions (21%). The aim of this study was to further assess the cause of goiter and the severity of iodine deficiency in children from this endemic area of Greece. Of the 800 children with clinically detectable goiter, 97 children (60 girls and 37 boys, 8-15 years) were recruited for determination of urinary iodine excretion, as well as assessment of thyroid volume and function and detection of antithyroid antibodies. The median urinary iodine concentration was 8.4 microg/dL, indicative of a mild iodine deficiency. Thyroid function was normal in all but 11 children who had subclinical hypothyroidism. Sixteen children (16.5%), including all those with subclinical hypothyroidism, were positive for antithyroid antibodies. Their median urinary iodine concentration (20.6 microg/dL) was higher compared to children who were negative for antibodies (7.4 microg/dL; p<0.001). The mean thyroid volume by ultrasonography (12.2+/-4.1 mL) was above the upper limit of normal for this age group. Thyroid volume was inversely related to the urinary iodine content in the children with negative antithyroid antibodies. Iodine deficiency is still prevalent in northwestern Greece although of mild severity and constitutes the primary cause of goiter among schoolchildren. However, it appears that autoimmune thyroiditis is emerging as a frequent cause of goiter in those children with sufficient iodine intake.

Development and application of competitive ELISA assays for rat LH and FSH.

Rat LH (rLH) and FSH (rFSH) were measured by sensitive and specific competition ELISAs. The rat LH ELISA used rLH-I-9 coated plates, an antiserum against rLH and an antibody against rabbit IgG labeled with peroxidase. Using rLH-RP-3 as a standard, rat LH was determined by binding of the anti-LH antibody to rLH-I-9 coated plates. The sensitivity of the assay was 0.8 ng/mL. Similarly, the rat FSH-ELISA used rFSH-I-8 coated plates, an antiserum against rFSH and an antibody against rabbit IgG labeled with peroxidase. Using rFSH-RP-3 as a standard, the FSH-ELISA was also determined by binding of the anti-FSH antibody to rFSH-I-8 coated plates. The sensitivity of this assay was 1.25 ng/mL. Both rat LH and FSH ELISA assays are highly specific and provide accurate determination of gonadotrophins in buffers, sera, cell culture media, and anterior pituitary extracts. These assays were used for monitoring the gonadotrophin surge-attenuating factor (GnSAF) and inhibin activities present in human follicular fluid (hFF). The 2 new ELISA procedures have practical advantages (safety, convenience, economy) over the RIA methods, and they perform as well as the RIA techniques at the same range of concentrations.

Effect of monensin and progesterone priming on ram-induced reproductive performance of boutsiko mountain breed ewes.

The effects of monensin and progesterone priming on reproductive performance (estrous response, lambing rate and prolificacy) of grazing Boutsiko mountain breed adult and 18-mo.-old ewes at the end of seasonal anestrus were investigated. In Experiment 1 the feed supplement with or without monensin was offered for 21 d after introduction of vasectomized rams (Day 0). Progesterone was administered to the ewes in the respective groups as a single injection at Day -3. Ewes of both age groups were assigned randomly to 1 of 4 treatments: C, C+P, C+M and C+M+P. In Experiment 2 the supplement C or M was offered from Day -26 to Day 21. The treatments consisted of C, C+P and C+M+P. Blood samples were taken 50 h after ram introduction for determination of plasma concentrations of P and insulin-like growth factor-I (IGF-I). There was a greater increase in estrous response at Days 17 to 19 and at Days 0 to 19 when supplementation was offered before rather than after ram introduction in both age groups. In the adult group ewes synchronization of estrus at Days 17 to 19 was significantly increased by administration of monensin (P<0.05) and progesterone (P<0.01) compared with the control group in the first but not the second experiment. The incidence of estrus at Days 17 to 19 or at Days 0 to 19 was highest in the adult groups treated with monensin and progesterone in both experiments. In 18-mo.-old ewes progesterone was effective in synchronizing estrus only in Experiment 2. Mean plasma IGF-I concentrations were increased by monensin treatment (P<0.05) in adult ewes that were at the periovulatory stage at blood sampling time. Correlation coefficients between IGF-I and progesterone concentrations in monensin plus progesterone group adults were -0.715 (P<0.02) and -0.516 (P<0.01), respectively across all treatments. The results suggest that monensin and progesterone priming improved reproductive performance, and the monensin-induced increase in plasma IGF-I levels at the periovulatory stage may be causally related to the ability of ovulatory follicles to develop into functional corpora lutea (CL).