Yesim Ozarda Ilcol

Leptin concentration in breast milk and its relationship to duration of lactation and hormonal status

BackgroundLeptin, a hormone present in breast milk, is involved in energy regulation and metabolism. The objectives of this study were to assess leptin concentrations in breast milk during the first 180 days postpartum, and to determine the relationship between the concentrations of milk leptin and circulating hormone levels in lactating women.MethodsBetween April 2005 and January 2006, blood and breast milk samples were collected from 160 breastfeeding women enrolled either in the first three days (n = 37; colostrum), days 4–14 (n = 27; transitional milk), days 15–30 (n = 16; early mature milk), days 31–90 (n = 37; mature milk) or days 91–180 (n = 43; late mature milk) postpartum. Milk and serum leptin levels were measured by immunoradiometric assay. Cortisol was measured by radioimmunoassay method. Serum insulin, estradiol, prolactin and thyroxine were measured by chemiluminescent immunometric method.ResultsLeptin concentrations in breast milk were highest (3.28 ± 0.41 ng/ml) in colostrum, decreased during the first 180 days of lactation, showing a significant inverse relation (r = -0.694, p < 0.001) with the days of lactation. Colostrum leptin concentrations correlated with maternal serum leptin (r = 0.425, p < 0.01), cortisol (r = 0.549, p < 0.01) and thyroxine (r = -0.530, p < 0.01). Mature milk leptin concentrations correlated with maternal serum leptin (r = 0.547, p < 0.001), insulin (r = 0.331, p < 0.05) and thyroxine (r = -0.329, p < 0.01). Serum leptin concentrations correlated with serum insulin (r = 0.648, p < 0.001), estradiol (r = 0.639, p < 0.001), prolactin (r = 0.530, p < 0.001) and thyroxine (r = -0.327, p < 0.05) concentrations during days 1–3 postpartum. During 15–180 postpartum days, serum leptin concentrations correlated with serum insulin (r = 0.271, p < 0.01), and thyroxine (r = -0.345, p < 0.001).ConclusionLeptin concentrations in breast milk decrease with time during lactation and show significant relationships with other maternal hormones.

Active and total ghrelin concentrations increase in breast milk during lactation.

Aim: To assess ghrelin status in breast milk and maternal serum for up to 180 days during lactation and to determine relationships between the concentrations of ghrelin in mothers milk and in serum of breastfed infants.

Endotoxin increases plasma leptin and ghrelin levels in dogs.

Objective:Evaluations of plasma leptin and ghrelin levels and their relations with circulating levels of proinflammatory mediators, stress hormones, and biochemical markers of hepatorenal injury during experimental endotoxemia in dogs. Setting:Uludag University. Design:Placebo-controlled animal study. Animals:Adult mongrel dogs (n = 16). Interventions:Intravenous injection of endotoxin (1 mg/kg) and blood sample withdrawal before and at 0.5–48 hrs posttreatment. Measurements and Main Results:Mean baseline plasma leptin and ghrelin levels were 2.4 ± 0.1 ng/mL and 867 ± 58 pg/mL, respectively. Plasma leptin and ghrelin increased significantly by 16% (p < .05) and 72% (p < .001) at 0.5 hr, and they remained elevated by 33–41% (p < .001) and 59–74% (p < .001) at 48 hrs after administration of endotoxin, respectively. There was positive correlation (r = .844; p < .001) between plasma leptin and ghrelin levels in endotoxin-treated dogs. Endotoxemia was associated with several-fold elevations in circulating levels of stress hormones, proinflammatory mediators, and hepatorenal injury markers. Plasma leptin and ghrelin levels in endotoxin-treated dogs were correlated with serum nitric oxide (r = .955 and r = .890; p < .001), procalcitonin (r = .825 and r = .716; p < .001), cortisol (r = .823 and r = .786; p < .001), and hepatorenal injury markers (r = .580 to .745 and r = .393 to .574; p < .05 to .01). Conclusions:Circulating leptin and ghrelin levels increase during endotoxemia, and these increases are associated with elevated levels of proinflammatory mediators, stress hormones, and serum biochemical markers for hepatorenal dysfunction.

Endotoxin alters serum-free choline and phospholipid-bound choline concentrations, and choline administration attenuates endotoxin-induced organ injury in dogs.

This study in dogs was performed to assess circulating choline status during endotoxemia and to determine whether choline administration can protect dogs from endotoxin-induced tissue injuries. Baseline serum-free and phospholipid-bound choline concentrations were 19.2 ± 0.6 μmol/L and 3700 ± 70 μmol/L, respectively. After intravenous endotoxin infusion, serum-free choline concentrations decreased by 14% to 49% (P < 0.05-0.001) at 2 to 6 h after 0.02 mg/kg endotoxin, and increased by 23% to 98% (P < 0.05-0.001) at 1 to 48 h after 1 mg/kg endotoxin. Serum phospholipid-bound choline concentrations increased by 19% to 27% (P < 0.05) at 12 to 24 h or by 18% to 53% (P < 0.05-0.001) at 1 to 48 h after 0.02 or 1 mg/kg endotoxin, respectively. The changes in serum-free and -bound choline levels in response to endotoxin were accompanied by dose- and time-related elevations in serum cortisol and biochemical markers for tissue injury and/or organ dysfunction. Intravenous administration of choline (20 mg/kg) 5 min before, and 4 and 8 h after endotoxin (1 mg/kg) attenuated endotoxin-induced elevations in serum alanine aminotransferase (P < 0.05-0.001), aspartate aminotransferase (P < 0.05-0.001), γ−glutamyl transferase (P < 0.05-0.001), alkaline phosphatase (P < 0.05-0.001), lactate dehydrogenase (P < 0.05-0.001), myocardial creatine kinase (P < 0.001), urea (P < 0.05-0.01), creatinine (P < 0.05), uric acid (P < 0.01-0.001), and tissue necrosis factor-α (P < 0.001). Choline also attenuated alanine aminotransferase (P < 0.05-0.01), alkaline phosphatase (P < 0.05-0.01), lactate dehydrogenase (P < 0.05-0.01), creatine kinase (P < 0.05-0.001), myocardial creatine kinase (P < 0.05-0.001), and uric acid (P < 0.05-0.01), but failed to alter the serum urea, creatinine, aspartate aminotransferase, and γ-glutamyl transferase responses to 0.02 mg/kg endotoxin. These data show that choline status is altered during endotoxemia and that choline administration diminishes endotoxin-induced tissue injury.

Resistin is present in human breast milk and it correlates with maternal hormonal status and serum level of C-reactive protein

Abstract Background: The main objectives of our study were to determine whether resistin was present in human breast milk and to assess resistin status in breast milk and serum in breastfeeding women for up to 180 days post-partum. Methods: Blood and breast milk samples were collected from 160 breastfeeding women enrolled on 1–3, 4–14, 15–30, 31–90 or 91–180 post-partum days. Blood samples were collected from 48 breast-fed infants at 8–24 days after birth. Milk and serum resistin levels were measured by ELISA. Results: Serum and breast milk resistin concentrations were highest (5800±1100 and 1710±68 pg/mL, respectively) at 1–3 post-partum days and decreased to 1645±210 and 1130±115 pg/mL, 1600±105 and 710±25 pg/mL, 1980±155 and 595±20 pg/mL and to 2060±300 and 670±18 pg/mL at 4–14, 15–30, 31–90 and 91–180 post-partum days, respectively. Serum resistin concentrations were correlated with those of milk (r=0.822, p<0.001). Both milk and serum resistin concentrations were correlated positively with maternal serum estradiol, progesterone, prolactin, thyroxine, triiodothyronine, cortisol, leptin and C-reactive protein concentrations. Serum resistin concentration in breast-fed infants (4915±340 pg/mL) was higher than that observed in their consumed breast milk (1745±70 pg/mL, p<0.001) or in serum of their breastfeeding mothers (3760±360 pg/mL, p<0.05). Conclusions: Resistin is present in human breast milk and its concentration in breast milk decreases with time during lactation. Its concentrations in breast milk and serum are correlated with circulating levels of various reproductive and metabolic hormones and with those of the general inflammatory marker, C-reactive protein. Clin Chem Lab Med 2008;46:118–24.

Evaluation of platelet count and its association with plateletcrit, mean platelet volume, and platelet size distribution width in a canine model of endotoxemia

BACKGROUND Platelets are of great importance in the pathogenesis of endotoxemia. Although thrombocytopenia is used as a diagnostic sign of endotoxemia, changes in values for platelet indices (plateletcrit [PCT], mean platelet volume [MPV], and platelet size distribution width [PDW]) in response to endotoxin are still unknown. OBJECTIVE The aim of this study was to evaluate platelet count and its relations with platelet indices in a canine model of endotoxemia. METHODS Twenty dogs were divided into 2 groups of 10 each, and treated intravenously with Escherichia coli endotoxin (1 mg/kg) or vehicle. Venous blood samples were collected before treatment (0 hour) and 0.5, 1, 2, 4, 6, 8, 12, and 24 hours after treatment. Platelet counts and indices were determined on a CELL-DYN hematology analyzer. RESULTS The platelet count and PCT decreased by a mean of 73% and 93%, respectively (P<.001), at 0.5 hour, and remained 70% and 85% lower than baseline values (P<.001) for 24 hours after endotoxin injection. MPV and PDW increased by a mean of 28% and 45%, respectively (P<.01), at 0.5 hour, and remained increased by 7% and 16% over baseline values for 24 hours (P<.01-.001). Platelet count correlated positively with PCT (P<.001), but correlated negatively with MPV (P<.001) and PDW (P<.01). CONCLUSIONS Changes in platelet count and its association with platelet indices may reflect changes in platelet production and reactivity. Platelet indices have potential value in the diagnosis and monitoring of dogs and humans with endotoxemia.

Intravenous administration of choline or cdp-choline improves platelet count and platelet closure times in endotoxin-treated dogs.

This study was performed to assess the effects of intravenous choline chloride and cytidine-5′-diphosphate choline (CDP-choline) treatments on circulating platelet, white blood cell, and red blood cell counts and platelet functions in response to endotoxin. Saline (0.2 mL/kg), choline chloride (20 mg/kg), or CDP-choline (70 mg/kg) were given intravenously three times at 4-h intervals, and endotoxemia was induced by endotoxin (E. coli 055:B5, 20 μg/kg) infusion, 5 min after the first treatment. Blood samples were collected before and at multiple time points after the challenge, for a panel of hematologic parameters and platelet closure times measured by PFA-100™. In saline-treated dogs, circulating platelet counts decreased by 85% (P < 0.001) at 0.5 h and remained low by 36%-80% (P < 0.5-0.001) 1-12 h after endotoxin. Circulating WBC counts decreased by 80%-90% (P < 0.001) at 0.5-2 h, and increased (P < 0.001) by 190% 12 h after the endotoxin. In response to endotoxin, RBCs increased by 10%-13% (P < 0.05) at 1-12 h. Endotoxin-induced decline in circulating platelets was attenuated at 0.5 h (P < 0.05-0.01) and reversed at 1-12 h (P < 0.05-0.001) by choline. Platelet closure times were shortened from 81 ± 10 s and 135 ± 10 s to 29 ± 5 s (P < 0.001) and 60 ± 3 s (P < 0.001) at 0.5 h, and prolonged (P < 0.001) at 1-8 h after endotoxin induction. Endotoxin-induced shortening in platelet closure times was attenuated (P < 0.05) and blocked (P < 0.01) by choline and CDP-choline, respectively. These results showed that choline and CDP-choline treatments improved circulating platelet counts and platelet function during endotoxemia in dogs.

Peripheral administration of CDP-choline and its cholinergic metabolites increases serum insulin: Muscarinic and nicotinic acetylcholine receptors are both involved in their actions

The present study was designed to test the effects of CDP-choline and its metabolites on serum insulin concentrations in rats and to investigate the involvements of cholinergic and adrenergic receptors in the effect. Intraperitoneal (i.p.) administration of CDP-choline (200-600 micromol/kg) increased serum insulin in a dose- and time-related manner. Equivalent doses (200-600 micromol/kg; i.p.) of phosphocholine or choline also increased serum insulin dose-dependently. Serum-free choline concentrations increased several-fold following i.p. administration of CDP-choline, phosphocholine or choline itself. In contrast, equivalent doses of cytidine monophosphate and cytidine failed to alter serum insulin concentrations. The increases in serum insulin induced by i.p. 600 micromol/kg of CDP-choline, phosphocholine or choline were abolished by pretreatment with the ganglionic nicotinic acetylcholine receptor antagonist hexamethonium (15 mg/kg; i.p.), or by the muscarinic receptor antagonist atropine methylnitrate (2 mg/kg; i.p.). Pretreatment with prazosin (0.5 mg/kg; i.p.), an alpha(1)-adrenoceptor antagonist, or yohimbine (5 mg/kg, i.p.), an alpha(2)-adrenoceptor antagonist, enhanced slightly the increases in serum insulin in response to 600 micromol/kg of CDP-choline, phosphocholine and choline. Serum insulin also increased following central administration of choline; the effect was blocked by intracerebroventricularly injected atropine, mecamylamine or hemicholinium-3 (HC-3). It is concluded that CDP-choline or its cholinergic metabolites phosphocholine and choline increases circulating insulin concentrations by increasing muscarinic and nicotinic cholinergic neurotransmission in the insulin secreting beta-cells.

The decline in serum choline concentration in humans during and after surgery is associated with the elevation of cortisol, adrenocorticotropic hormone, prolactin and β-endorphin concentrations

Serum choline concentrations decrease during and after surgery. We undertook this study to determine whether the decrease of choline is associated with an increase in stress hormones. In 16 patients undergoing abdominal surgery with general anesthesia, circulating choline cortisol, prolactin, adrenocorticotropic hormone (ACTH) and -endorphin levels were measured before, during and after surgery. Choline levels decreased by 41% (P<0.01) during surgery, remained 15-38% decreased for 48 h, and returned to preoperative values 72 h after surgery. The decrease in serum choline was associated and inversely correlated with the increase in serum cortisol (P<0.001; r = -0.642), prolactin (P<0.001; r = -0.756), -endorphin (P<0.001; r = -0.726) and ACTH (P<0.01; r = -0.458). In conclusion, we found that abdominal surgery induces a decline in serum choline associated with an increase in circulating cortisol, prolactin, ACTH and -endorphin.

Choline Or Cdp-choline Alters Serum Lipid Responses To Endotoxin In Dogs And Rats: Involvement Of The Peripheral Nicotinic Acetylcholine Receptors

We showed previously that choline administration protects dogs from endotoxin-induced multiple organ injury and platelet dysfunctions. Because sepsis/endotoxemia is associated with alterations in lipid metabolism, we have investigated whether choline or cytidine-5&vprime;-diphosphate choline, a choline donor, alters serum lipid responses to endotoxin in dogs and rats. In response to endotoxin, serum concentrations of triglycerides, choline-containing phospholipids, total cholesterol, and high-density lipoprotein cholesterol increased in a dose- and time-related manner. Administration of choline (20 mg/kg i.v. in dogs or 90 mg/kg i.p. in rats) or cytidine-5&vprime;-diphosphate choline (70 mg/kg i.v. in dogs) 5 min before and 4 and 8 h after endotoxin blocked or attenuated the increases in serum triglycerides, total cholesterol, and nonesterified fatty acids. Endotoxin-induced elevations in serum phospholipid levels did not change in rats and were enhanced in dogs by choline. In rats, serum lipid response to endotoxin was accompanied by severalfold elevations in serum levels of hepatorenal injury markers; their elevations were also blocked by choline. Pretreatment with hexamethonium blocked cholines effects on serum lipids and hepatorenal injury markers. Pretreatment with atropine blocked endotoxin-induced elevations in serum lipid and hepatorenal injury markers, but failed to alter cholines actions on these parameters. Choline treatment improved survival rate of rats in lethal endotoxin shock. In conclusion, these data show that choline treatment alters serum lipid responses to endotoxin and prevents hepatorenal injury during endotoxemia through a nicotinic acetylcholine receptor-mediated mechanism. Hence, choline and choline-containing compounds may have a therapeutic potential in the treatment of endotoxemia/sepsis.