Identification of corticosteroid-binding globulin in human milk: measurement with a filter disk assay

Elevated maternal corticosterone during lactation hinders the neonatal adaptive immune response to herpes simplex virus (HSV) infection

The neonate's immune system is relatively immature. For short-term protection against pathogens the neonate is reliant primarily on maternally derived antibodies delivered via the mother's milk. However, neonates soon acquire the ability to generate adaptive immune responses for long-term protection. Products of the nervous and endocrine systems that are elicited by psychological stress are known to modulate a variety of immune responses. Additionally, psychological stressors are well recognized for their ability to increase corticosterone levels. The studies described herein examined the effects of increases in maternally derived corticosterone on the neonatal cell-mediated immune response to, and pathogenicity of, herpes simplex virus (HSV) infection. Water containing corticosterone was made available to nursing mothers for a period of 6 consecutive days beginning on either the day of or 6 days post-delivery. At 12 days of age, neonates were infected with HSV-1 in the rear footpads. These neonates exhibited a decrease in the proliferative ability of splenic-derived cells due to the reduction of IL-2 production and IL-2 receptor alpha subunit (IL-2R alpha) expression by these cells. These neonates also exhibited a decrease in the number and function of popliteal lymph node-resident HSV-1 gB(498-505) peptide-specific CD8(+) T cells as measured by tetramer analysis, CTL lytic activity, expression of CD107a, cytokine production, and proliferation. Additionally, these HSV-infected neonates exhibited increased morbidity and mortality. Together, these studies indicate that exposure of neonates to maternally derived corticosterone via the milk hinders their ability to generate an adaptive cell-mediated immune response to a viral infection and illustrate the potential importance of maternal stress in neonatal resistance to infectious pathogens.

Multicentred clinical study of the metabolic effect of the monthly injectable contraceptive containing dihydroxyprogesterone acetophenide 150 mg + estradiol enanthate 10 mg

The metabolic effect of the monthly injectable contraceptive containing dihydroxyprogesterone acetophenide (DHPA) 150 mg + estradiol enanthate (EEn) 10 mg was compared to that of other regularly used contraceptive methods (pills containing: ethinylestradiol (EE) 0.050 mg + levonorgestrel (LNG) 0.250 mg, EE 0.030 mg + LNG 0.150 mg; EE 0.030/0.040/0.030 mg + LNG 0.050/0.075/0.0125 mg; norethisterone enanthate (NEE) 200 mg i.m.; non-hormonal methods). Serum triglycerides, HDL/LDL-cholesterol, copper, ceruloplasmin, total and free cortisol, CBG, total and free testosterone and SHBG in chronic users were determined. A total of 237 women took part in this study. Taking users of non-hormonal methods as control, triglyceride levels were higher, and total and free testosterone levels were lower in women using DHPA 150 mg + EEn 10 mg and in those taking contraceptive pills (p less than 0.05 - 0.01). Such modifications were slightly less in the group using the injectable. The effects of DHPA 150 mg + EEn 10 mg on HDL/LDL-cholesterol copper, ceruloplasmin, CBG, total and free cortisol and SHBG were rare or non-existent. Nevertheless, the contraceptive pills (even the low-dose formulations) correlate with modifications of all those variables, which were highly significant in comparison with the injectable (p less than 0.01) and with non-hormonal methods (p less than 0.01); there were no differences between the last two methods. The results suggest that the metabolic effect of DHPA 150 mg + EEn 10 mg is not higher than that of the commonly used oral contraceptives. On the other hand, they do not suggest that the dose contained in this injectable is exaggerated. There is no evidence that it produces accumulation of effects in the organism. These findings should be taken into account when referring to the long-term safety of this injectable.

Induction of adenylate cyclase in a mammary carcinoma cell line by human corticosteroid-binding globulin

Corticosteroid-Binding globulin (CBG) is a plasma protein that binds certain steroid hormones, mainly cortisol and progesterone. It has been demonstrated recently that specific binding sites for this protein exist on cell membranes. In this communication we establish that binding to these sites results in the induction of adenylate cyclase activity and the accumulation of cAMP in MCF-7 cells. These events are critically dependent upon a steroid being bound to CBG. These data are consistent with the hypothesis that CBG is a prohormone which is activated when cortisol is bound to it.

Identification and quantitation of free and conjugated steroids in milk from lactating women

A method for analysis of metabolic profiles of free and conjugated steroids in milk has been developed. Milk is diluted with aqueous triethylamine sulphate and liquid-solid extraction is achieved on a Sep-Pak C18 cartridge at 60-64 degrees C. Steroids are purified by chromatography on small columns of Lipidex 5000 and sulphohydroxypropyl Sephadex LH-20 [H+] prior to separation into neutral and phenolic compounds, glucuronide, mono- and disulphate conjugate groups on the lipophilic strong anion exchanger triethylaminohydroxypropyl Sephadex LH-20 (TEAP-LH-20). Conjugated steroids are released by enzymatic or solvolytic procedures and separated into a neutral and a phenolic fraction on TEAP-LH-20. The O-methyloxime and trimethylsilyl ether derivatives of the steroids are analyzed by capillary column gas chromatography-mass spectrometry. Fifty steroids were identified in milk collected from women a few days after delivery. Quantitatively about 80% were present as sulphates, 15% as glucuronides and only 5% were unconjugated steroids. The steroid pattern was similar to that in late pregnancy plasma with pregnanolone, pregnanediol and pregnanetriol isomers and dehydroepiandrosterone being predominant. About 10% of the steroid content consisted of estrogens. The total concentration of steroids 2 days after delivery was 20-116 ng/ml, i.e. about 1-5% of the concentration was about 10 ng/ml 1 month after delivery. In one milk sample, collected 2 days after delivery, the steroid concentration (3.6 micrograms/ml) was similar to that in plasma.

Comparison of total and free cortisol in bovine serum and milk or colostrum

Total (free plus protein-bound) and free cortisol concentrations in paired samples of serum and skim milk or colostrum were determined by specific radioimmunoassay after extraction or ultrafiltration. For 11 cows in established lactation mean total cortisol concentrations +/- SE in serum and milk were 4.5 +/- .7 ng/ml and .35 +/- .06 ng/ml, respectively. Concentrations of free cortisol in serum and milk were about .3 ng/ml, which is at the lower limit of the present assay. Following 200 IU Synacthen injection to 5 cows, total cortisol in serum and milk rose to 67 +/- 6.0 ng/ml and 11.4 +/- 1.5 ng/ml by 8 h postinjection, while free concentrations increased to 4.3 +/- .7 ng/ml and 6.5 +/- .8 ng/ml in serum and milk, respectively. Eight additional cows were sampled at 1 to 2 d after parturition, and total cortisol in serum and colostrum was 16.6 +/- 1.6 ng/ml and 4.4 +/- 1.3 ng/ml, and free cortisol was 2.4 +/- .4 ng/ml and 1.8 +/- .5 ng/ml, respectively. Free cortisol concentrations in colostrum or in milk from cows in established lactation, before or after adrenal stimulation, are directly related to free cortisol concentrations in the blood, while the bound cortisol in milk is more related to these two stages of lactation rather than the bound hormone in the blood. Measurement of free cortisol in milk should allow the monitoring of changes in plasma free cortisol in studies of stress in dairy cows.

Evidence for a transcortin-like component in human breast cyst fluid

The occurrence of a specific glucocorticoid binding activity was investigated in breast cyst fluid (BCF) samples aspirated from 481 women under treatment for breast cystic disease. [3H]cortisol was incubated with BCF at 4 degrees C with and without 100-fold molar excess of non-radioactive steroid in order to account for non-specific binding. Corticosterone, progesterone and dexamethasone-binding activities were also investigated in about 50% of the specimens. Consistent amounts of a specific cortisol-, corticosterone- and progesterone-binding component were observed in about 30% of samples. Apparent binding values ranged from 4.31 to 80.78 nmol/l for cortisol, from 3.94 to 75.72 nmol/l for corticosterone, and from 1.18 to 16.45 nmol/l for progesterone. No specific binding for dexamethasone was detected. Scatchard analyses for [3H]cortisol and [3H]progesterone were made in pools of 'positive' BCF, human serum and whey of human milk, respectively. The mean values of the apparent equilibrium association constant (Ka) were compatible with the existence of high affinity protein-hormone interactions in each considered medium. Data obtained in ligand competition experiments for different steroid molecules suggest the similarity of the glucocorticoid- and progesterone-binding component found in 30% of BCF samples examined with the plasma corticosteroid-binding globulin (CBG, transcortin) and especially with the transcortin-like component detected in the whey of the human milk. It is suggested that the transcortin-like component may play an important role in controlling kinetics of transport and in regulating the effective levels of cortisol and progesterone in numerous breast cyst fluids.

Cortisol and its possible role in regulation of sodium and potassium in human milk

Cortisol (F), Na, and K were measured in human milk samples taken every 4 h during 28 24-h cycles in 19 subjects. F in milk, measured by radioimmunoassay of unchromatographed extracts, demonstrated a circadian variation similar to that of plasma F and was dexamethasone-suppressible. Values ranged from 220 +/- 41 (SE) ng/dl at 2300 h to 1,214 +/- 210 at 0700 h. When milk extracts were chromatographed, a similar circadian variation was seen, and F ranged from 87 +/- 27 (SE) ng/dl at 2300 h to 784 +/- 164 at 700 h. The morning values of F exceeded previous estimates of corticosteroid binding capacity in milk, indicating the possibility of significant levels of unbound F. The subjects were divided into three groups according to time postpartum: I, 3.5-6 wk; II, 8-18 wk, and III, 20-32 wk. In milk, normalized values of F (unchromatographed) and electrolytes (x/means) were compared, with x the value at time t and means the mean value for a 24-h cycle. A significant circadian variation was seen in milk for (x/means)Na, (x/means)K, (x/means)Na/K, and x/means)F. Correlation of (x/means)F with (x/means)Na 4 h later was negative in all three groups (r = -0.36 to -0.56, P less than 0.10-0.001) as was (x/means)F vs. (x/means)Na/K (r = -0.33 to -0.61, P less than 0.10-0.001); (x/means)F vs. (x/means)K 4 h later was positive (r = 0.38 to 0.52, P less than 0.05-0.001). Dexamethasone administration caused a significant decrease in milk means Na and an increase in meansK in all five subjects (P less than 0.01). Thus, milk Na and K concentrations appeared regulated by adrenal corticosteroids.

Nuclear glucocorticoid binding in chronic lymphatic leukemia lymphocytes

A reliable procedure is described for isolating 3H-triamcinolone acetonide (3H-TA) receptor complexes from purified chronic lymphatic leukemia (CLL) lymphocyte nuclei, based on the use of carbobenzoxy-L-phenylalanine (CBZ-L-phe) to prevent breakdown of hormone-receptor complexes during extraction of nuclei with 0.6M KCl. Using this method, specific nuclear glucocorticoid binding was demonstrated in 14/14 patients with untreated CLL. No correlation was found between levels of nuclear-associated 3H-TA and peripheral white blood cell count or rosetting ability of circulating lymphocytes.