Host response to mycobacterial infection in the alcoholic rat: male and female dimorphism.

Increased susceptibility to tuberculosis occurs in the alcoholic. One explanation for the altered susceptibility is a change in T-lymphocyte modulation. To evaluate this, 24 male and 24 female Sprague-Dawley rats were treated with either a Lieber-type liquid ethanol diet (LED) or an isocaloric control (LCD). After 2 weeks, half the subjects were infected with BCG (10(8) colony-forming units) and sacrificed after 42 days. Splenic helper (CD4) and suppressor/cytoxic (CD8) cells were quantitated by flow cytometry. By three-way analysis of variance, splenic cellularity was significantly increased by infection (p < 0.0001) but suppressed by LED (p = 0.0002). There was a marginal sexual difference (p = 0.065) with females exhibiting a 35% lower response while on alcohol. Examining lymphocyte subsets, the most significant changes were observed after infection (BCG) and alcohol treatment (LED). CD4 levels were diminished by LED (p = 0.0002) but markedly increased by infection (p < 0.0001), producing a highly significant interaction that affected both absolute number (p < 0.0001) and relative percent present (p = 0.0078). CD8 was influenced only by infection (p < 0.0001). This resulted in a infection-related increase in the CD4/CD8 ratio which was lower with LED (p = 0.0032). Splenic T-lymphocytes, predominately CD4, are involved in the host response to BCG hepatitis and are adversely influenced by LED, which may contribute to increased susceptibility.

Biphasic in vivo immune function after low- versus high-dose alcohol consumption.

A series of experiments was performed to assess the alterations in immune status in vivo that are associated with differences in the amount and duration of ethanol intake. Using a nonspecific delayed cutaneous hypersensitivity-like response to the intradermal injection of phytohemagglutinin, the area of induration (skin test response) was significantly enhanced (p = 0.008) after low-dose ethanol (0.5 g/kg) administered daily by gastric gavage for 5 days. High-dose ethanol (6.0 g/kg) significantly diminished this response (p = 0.03). Using an experimental model of Mycobacterium bovis hepatitis, the host immune response was also altered in a biphasic manner after chronic, 28-day ethanol consumption. With this model 0.43 +/- 0.03 g/kg/day (mean +/- SEM) of ethanol (low dose) was associated with a 40% improvement in the removal of the organisms from liver tissue (p = 0.002). High dose (12.1 +/- 0.5 g/kg/day) impaired removal, resulting in a 55% increase in the number of viable organisms (p = 0.001). The levels of three cytokines, MIF, TNF-alpha, and IL-2, known to be involved in the modulation of the host response to mycobacterial infections, were measured in sera after the infection. The serum levels of these cytokines in response to infection did not correlate with this biphasic response to different alcohol dose levels.

Effects of recombinant human insulin-like growth factor-1 and recombinant human growth hormone on anabolism and immunity in calorie-restricted alcoholic rats.

UNLABELLED: Patients with severe alcoholic liver injury exhibit very low serum insulin-like growth factor-1 (IGF-1) concentrations, along with many of the symptoms that might occur with an IGF-1 deficiency state (including severe protein calorie malnutrition and immunosuppression). This study was performed to assess the effects of recombinant human (rh) IGF-1 and/or rh growth hormone (rhGH) on anabolism and immunity in the calorie-restricted, immunosuppressed alcoholic rat. METHODS: Undernutrition was induced by calorie restriction such that each animal consumed 40% of ad libitum-fed controls. Alcohol was administered orally in the diet such that the mean daily intake was 9.4 g/kg/day. rhIGF-1 was administered by continuous subcutaneous infusion (380 micrograms/day) using a 14-day miniosmotic pump; rhGH was given by subcutaneous injections (400 micrograms/day). Matching placebo groups were also studied. RESULTS: On this regimen, ad libitum-fed controls were well nourished and increased body weight 34%, whereas Restricted controls lost 7.7% and Restricted alcohol-fed rats lost 15.2%. Significant but incomplete reversal of undernutrition was achieved with hormone therapy. Best improvement was obtained with combined therapy: rhIGF-1 + rhGH (p < 0.005; placebo versus active treatments). Immunologic impairment was observed to be severe in both thymus and spleen. The most severe changes were seen in thymi of the calorie-restricted, alcohol-fed rats, wherein 98% of the T lymphocytes were lost. rhIGF-1 treatment, but not rhGH, produced significant improvements in thymus. This was most pronounced in control rats (p < 0.005). Splenic T lymphocytes were less impaired and were more responsive to rhIGF-1 treatment; there was a maximum loss of 71% of T cells in Restricted, alcohol-fed rats. rhIGF-1 treatment completely restored splenic cellularity, as well as each of the T lymphocytes studied: CD5, CD4, and CD8. Functional status of splenic T lymphocytes was assessed by blast transformation after concanavalin A stimulation. Calorie restriction did not impair significantly this function in controls [Lieber-DeCarli control diet (LCD)]. However, it was significantly impaired in the Restricted, alcohol-fed rats (p = 0.003). In the presence of continued calorie restriction and alcohol, this function was not restored with either hormone (rhIGF-1 and/or rhGH). Their role in facilitating functional recovery after calories is restored, and alcohol is discontinued is under investigation.

I: the effects of recombinant human insulin-like growth factor-1 on nutritional recovery in the malnourished alcoholic rat.

BACKGROUND/AIMS: Alcoholics with severe liver disease (ALD) typically demonstrate the findings of protein calorie malnutrition. Such an occurrence might be anticipated with insulin-like growth factor-1 (IGF-1) deficiency. Furthermore, serum levels of IGF-1 are frequently very low in patients with alcoholic liver disease. The present study was undertaken to evaluate in an in vivo rat model of alcoholism and malnutrition, the possibility of a therapeutic application for IGF-1. METHODS: Controlled injury was induced by 14 days of calorie restriction and alcohol feeding (phase 1), which induced a 9% loss of body mass. Changes were compared with pair-fed, calorie-restricted controls that lost 7.8% of body mass and to unrestricted control rats that gained 28% above their pretreatment body mass during the same period. Recovery was evaluated after 28 days of treatment using various combinations of: (1) high calorie intake, (2) cessation from alcohol feeding, and (3) IGF-1. RESULTS: Liver injury was minimal, but protein calorie malnutrition was moderately severe after phase 1 treatments. During recovery (phase 2), continuous consumption of alcohol--even in the presence of high calories and IGF-1 treatment--produced an incomplete nutritional recovery and, compared with normal rats, was associated with lower serum IGF-1 levels. The group treated with all three modalities (high calories, IGF-1, and abstinence from ethanol) had the most rapid and complete restoration of body weight. CONCLUSIONS: Recovery of nutritional status in the malnourished rat correlates significantly with serum IGF-1 levels. In the absence of ethanol and with sufficient caloric intake, IGF-1 treatment increased serum IGF-1 concentrations and accelerated nutritional recovery. Even with adequate calories, ethanol negated this recovery and was associated with lower serum IGF-1 concentrations. Further studies, both basic and clinical, are needed to better understand the mechanisms involved and to establish whether in patients with severe liver disease IGF-1 treatment would produce an accelerated improvement in nutritional status and improve both morbity and mortality. These animal studies suggest that this is the case.

II: the effects of recombinant human insulin-like growth factor-1 on immunological recovery in the malnourished alcoholic rat.

BACKGROUND/AIMS: Immunological abnormalities are frequently observed in alcoholics with severe liver disease and are typically in association with immune abnormalities. Concomitantly, serum levels of insulin-like growth factor-1 (IGF-1) are frequently very low in these patients. Because IGF-1 is known to modulate both nutrition and immune status, the present study was undertaken to evaluate an in vivo rat model of alcoholism and malnutrition, the possibility of a therapeutic application for IGF-1. METHODS: Controlled injury was induced by 14 days of calorie restriction and alcohol feeding that resulted in a 9% loss of body mass. Changes were compared with normal unrestricted control rats that gained 28% above their pretreatment body mass during the same period. Immunological impairment was assessed using thymus and spleen mass, cellularity and spleen T-lymphocyte function. Recovery was evaluated after 28 days of treatment using various combinations of: (1) high calorie intake, (2) cessation from alcohol feeding, and (3) IGF-1. RESULTS: The thymus was most severely affected, losing 52.3% of its mass and 55.7% of its cellularity. The spleen was diminished, losing 31.2% of its mass and 41.9% of its cellularity. All of the spleen T-lymphocyte subsets were diminished, with CD5 affected the least (37.1 %) and CD8 affected the most severely (51.7%). During recovery, only the group treated with high calorie intake, no alcohol intake, and IGF-1 (group 8) had complete restoration of all immunological parameters, including a recovery of T-lymphocyte function. Continuous consumption of alcohol, even in the presence of high calories and IGF-1, produced an incomplete recovery. CONCLUSIONS: Cessation of alcohol coupled with high calorie nutrition and IGF-1 treatment produced an accelerated improvement in host immunity. These animal studies suggest that IGF-1 is efficacious for this condition and supports the need for additional clinical studies.

Human hepatocyte growth factor in alcoholic liver disease: a comparison with change in alpha-fetoprotein. Department of Veterans Affairs Cooperative Study Group 275.

To evaluate the hepatic regenerative response in patients with alcoholic liver disease, sera from 263 patients with severe alcoholic hepatitis and/or cirrhosis were analyzed for hepatocyte growth factor (HGF) and alpha-fetoprotein (AFP). HGF concentration was elevated above healthy controls in 95% of the patients (median level = 2.4 ng/ml), whereas AFP tended to be depressed below controls (median level = 4.1 ng/ml). Correlations with parameters of liver injury (i.e., ascites, encephalopathy, AST bilirubin, and protime) all showed a more significant correlation with HGF concentrations than those of AFP. Patients with HGF levels below the mean (4 ng/ml) exhibited significantly better survival (median survival = 35 months vs. 8.5 months for those with HGF > or = 4 ng/ml; p = 0.007). Serum HGF levels were associated with various specific histologic features of alcoholic hepatitis that included, but were not exclusively related to, necrosis.

Effects of electromagnetic fields and gender on neurotransmitters and amino acids in rats.

Epidemiological studies have linked electromagnetic field (EMF) exposure to certain forms of cancer, however only limited laboratory evidence supports a connection between EMF and biological effects. In the present study we exposed male and female rats to low level, 1000 milli-Gauss (mGs), direct current EMF generated with Helmholtz coils for 1 mo or 4 mo. The effects of these EMF exposures on regional brain neurotransmitter metabolism and circulating amino acid concentrations were determined. After 1 mo of EMF exposure the concentration of serotonin was elevated in the hypothalamus of male rats. Levels of the dopamine metabolite, 3-methoxytyramine, were increased in the corpus striatum of male and female rats that were exposed to EMF for 1 mo. Hypothalamic concentration of norepinephrine was elevated in both groups of male rats, as compared to respective female groups, but was not affected by EMF. Similarly, levels of tyrosine were increased in hypothalamus, corpus striatum and nucleus accumbens of male rats, but were not affected by EMF exposure. Following 4 mo of EMF exposure, no significant effect of EMF was observed. Significant sex differences in plasma amino acid concentrations were observed in both studies, with female rats exhibiting decreases in a majority of the amino acids measured. These results are suggestive that short-term exposure may cause small alterations in neurotransmitter metabolism and in circulating amino acids, which dissipate when exposure duration is increased.

Inhibition of constitutive and inducible cyclooxygenase activity in human platelets and mononuclear cells by NSAIDs and Cox 2 inhibitors.

A range of NSAIDs and reported Cox 2 selective compounds were tested in human freshly isolated platelets and LPS-stimulated mononuclear cells to determine their potency and selectivity as inhibitors of constitutive (presumably Cox 1) and inducible (presumably Cox 2) cyclooxygenase respectively. All compounds tested were either equipotent at inhibiting constitutive and inducible cyclooxygenase or were selective for the inducible form. The most selective compound was Dup697 and the least selective, ketoprofen. Several compounds only produced a partial inhibition of constitutive cyclooxygenase as the maximum inhibitor concentration achievable in the assay was limited to 1 mM. With the exception of paracetamol, all compounds were able to produce full inhibition curves against the inducible form. Potency estimates against constitutive Cox compare closely with published data but most compounds were consistently more potent against the inducible isoform than in published data for human cloned, microsomal Cox 2. These data suggest that human mononuclear cells are either exquisitely sensitive to some NSAIDs or they may contain another Cox isoform as yet indistinguishable from Cox 2.

GR113808: a novel, selective antagonist with high affinity at the 5-HT4 receptor.

1. The 5-HT4 receptor has only recently been identified but has yet to be cloned. This paper describes the pharmacology of a potent and selective 5-HT4 receptor antagonist, GR113808, which will be useful in the further characterization of this receptor. 2. On the guinea-pig ascending colon, GR113808 (1 nM-0.1 microM) behaved as an antagonist of 5-hydroxytryptamine (5-HT)-induced contraction, producing rightward displacements of the concentration-effect curve to 5-HT and a concentration-related depression of the maximum effect. However, the compound had no effect on cholecystokinin (CCK-8)-induced contraction in concentrations up to 1 microM. 3. In the guinea-pig colon preparation, onset and offset of the antagonism by GR113808 of 5-HT-induced contraction was examined. Incubation of the tissues for either 15 min, 30 min or 60 min produced similar rightward displacements of the concentration-effect curves to 5-HT, with no increase in the degree of depression of the maxima with increasing time of incubation. Experiments examining offset of antagonism (0.01 microM) demonstrated that washout for 30 min was required to reverse fully the effects of the antagonist. 4. Potency estimates in the colon for GR113808 were made by determining approximate pA2 values (30 min) using the Gaddum equation. The values obtained were 9.2, 9.7 and 9.2 when tested against the agonists 5-HT, 5-methoxytryptamine and R,S-zacopride respectively. 5. On the carbachol-contracted tunica muscularis mucosae preparation of the rat thoracic oesophagus, GR113808 behaved as an antagonist of 5-HT-induced relaxation, producing no reduction in maximum response. Analysis of these data yielded a pA2 of 9.3. GR1 13808 also antagonised the relaxant effects of 5-methoxytryptamine (pA2 = 9.0) and R,S-zacopride (pA2 = 9.4). The compound had no effect on isoprenaline-induced relaxation of the carbachol-contracted oesophagus at a concentration of 1 MicroM.6. In tests of selectivity, GR113808 had only low affinity for 5-HT3 receptors (pKi = 6.0) and had no functional activity at either 5-HT2 or 5-HT1-like receptors on vascular smooth muscle preparations. In a range of binding assays, GRi 13808 was shown to have no appreciable affinity for any other receptor type investigated.7. In the anaesthetized piglet, GRI13808 was a potent antagonist of 5-methoxytryptamine-induced tachycardia (mean DRo = 97.2 microg kg-1 h-1). The compound was ineffective against isoprenaline-induced tachycardia.8. The present results are discussed in comparison with those for existing antagonists at the 5-HT4receptor. The results of this study indicate that GRI13808 will be a valuable antagonist for studying 5-HT4 receptor mechanisms in vitro and in vivo and validate its use as a radioligand for determining 5-HT4 receptor distribution.

The impact of age on alcohol toxicity in the rat.

This study was performed to determine whether the severity of chronic alcohol toxicity is altered by age and duration of drinking. Alcohol as 35% of calorie intake (ED treatment) was administered to Sprague-Dawley rats at predetermined ages beginning at 1, 6, 12, 18, 24 and 27 months for a duration of treatment varying from 1 to 3 months. The degree of injury was compared to controls (CD treatment) of comparable age and duration of treatment. ED was associated with significantly higher serum levels of AST, total bilirubin and alkaline phosphatase (P < 0.0001 for each test) without detectable differences due to age and duration of treatment. Liver triglycerides (as a measure of alcoholic fatty steatosis) were significantly increased by ED (P < 0.0001) and influenced by both age and duration of treatment. The greatest toxicity was observed in young animals. ED treatment beginning at 1 month of age was associated with an AST level 69% above CD and liver triglycerides 463% above CD; beginning at 18 months of age, ED produced an increase of 24% in AST and 175% in liver triglycerides. The hepatic regenerative capacity, as measured by 3H-thymidine uptake into nuclear DNA, was similarly affected by both ED and age. Regeneration was significantly higher in youth. ED produced a 62% increase above CD at 1 month compared to an 11% increase beginning at 18 months of age. These observations suggest that juveniles develop more severe injury from alcohol but that a greater regenerative capacity exists in youth. This may explain the observed clinical relationship between age and prognosis seen in patients with severe alcoholic liver injury.

Sex differences and the effects of alcohol on immune response in male and female rats.

Although it is clear that both alcohol and sex hormones impact immune function, very little information is available on the effects of alcohol on immune response in males versus females. We decided to determine if the alterations in immune response resulting from alcohol feeding might be expressed differently in males and females. To accomplish this we utilized pair-fed male and female Sprague-Dawley rats. Animals were fed a liquid diet for 60 days containing 30% of their calories as ethanol, and after 1 week this concentration was increased to 45% ethanol. Controls received liquid control diet of the same caloric and nutritional composition, and immune status was monitored with in vivo and in vitro techniques. Ethanol feeding significantly reduced the phytohemagglutinin skin response in males (p = 0.020) and females (p = 0.012). The concanavalin A blastogenic response of spleen cells prepared from female rats fed ethanol was significantly depressed with respect to spleen cells prepared from female rats fed the control diet (p = 0.0071). Alcohol also appeared to depress spleen cell blastogenic response in males, but this trend did not quite reach significance (p = 0.071). Spleen cells from groups of ethanol and control male and female rats were labeled with fluorescent monoclonal antibodies and run on a Fluorescent-Activated Cell Sorter. Ethanol significantly increased the percentage population of CD4 (T-helper cell) in males (p = 0.017), but not in females, and promoted an apparent, although nonsignificant, increase in the CD4/CD8 ratio in both sexes. An ELISA was used to measure IgM and IgG antibody elaborated by pokeweed mitogen-stimulated spleen cells in cultures.(ABSTRACT TRUNCATED AT 250 WORDS)

Impact of chronic alcoholism on the aging rat: changes in nutrition, liver composition, and mortality.

The adverse effects of chronic alcohol consumption (mean 6.68 g/kg/d) were assessed in 150 male Sprague-Dawley rats over their life span (25 months). Evaluations were performed at 2, 3, 8, 13, 19, and 25 months of age for changes in nutrition status, biochemical tests for liver injury, compositional changes in liver, and hepatic regenerative capacity. In spite of nearly identical caloric intake, alcohol treatment was associated with nutritional levels 10-30% lower than controls. Maximal changes were observed at the two extremes of ages (2-3 months and 19-25 months). Hence, a nutritional contribution to other adverse changes could not be excluded. Fatty compositional increases (triglycerides) occurred early (5-fold increases after 1 month of treatment) then declined to levels only slightly above controls. Biochemical tests on sera for liver injury (AST and total bilirubin) were consistently higher with alcohol treatment. Regenerative capacity measured by [3H]thymidine uptake after partial hepatectomy was initially elevated in the alcoholic then rapidly declined beyond 7 months of age. In control animals, an age-related decline was also observed but occurred later beyond 12 months of age. Consistent with these adverse effects, ethanol diet survival was poorer than the pair-fed control groups by 15% (median survival for alcoholics, 17 months vs. 20 months in controls.

Development of a radioligand binding assay for 5-HT4 receptors in guinea-pig and rat brain.

1. The 5-HT4 receptor antagonist, GR113808, has been radiolabelled to a high specific activity with tritium. 2. Characterization of specific [3H]-GR113808 binding in homogenates of guinea-pig striatum and hippocampus revealed a single site of high affinity (Kd values 0.20 and 0.13 nM respectively). 3. [3H]-GR113808 binding was reversible and displayed rapid kinetics such that association and dissociation were complete within 3 min. 4. Specific [3H]-GR113808 binding was potently and stereoselectively inhibited by agonists and antagonists acting at the 5-HT4 receptor but not by compounds selective for other 5-HT receptors or other neurotransmitter receptors. 5. Autoradiographic analysis revealed a discrete localization in both guinea-pig and rat brain with high concentrations of binding in brain areas such as the striatum, substantia nigra and olfactory tubercle. 6. [3H]-GR113808 binding to homogenates of guinea-pig striatum meets the criteria for labelling of the 5-HT4 receptor and, as such, represents the first characterization of this receptor in a radioligand binding assay.

Antibodies to hepatitis B virus and hepatitis C virus in alcoholic hepatitis and cirrhosis: their prevalence and clinical relevance. The VA Cooperative Study Group (No. 119)

Patients with overt alcoholic liver disease who had participated in a multicenter therapeutic trial and subgroups of controls (i.e., alcoholic patients without liver disease and patients with neither alcoholism nor liver disease) were tested for hepatitis B virus and hepatitis C virus antibodies to determine the prevalence of these antibodies to determine the prevalence of these antibodies and any clinical association in the progression and outcome of alcoholic liver disease. Antibodies to hepatitis B (anti-HBs and/or anti-HBc) were found in 29.2% of patients with alcoholic liver disease, in 26.1% of hospitalized alcoholic patients without liver disease and in 24.2% of hospitalized nonalcoholic patients without liver disease; frequencies were not significantly different from one another. HBsAg was not evaluated because HBsAg+ patients had been excluded from the original trial. The presence of these antibody markers correlated with ethnic origin of and immunoglobulin levels in the patients. In contrast, antibody to hepatitis C, as detected by enzyme immunoassay, was positive in 27.1%, 4.8% and 3.0% of the three groups, respectively, the first differing significantly from the other two. Antibody to hepatitis C virus positivity correlated significantly with clinical severity of the disease and with the presence of histological features that imply chronic viral infection (periportal inflammation, cirrhosis), despite the fact that the supplementary assay for antibody to hepatitis C virus, using recombinant immunoblot assay, reduced the positive rate by 79%.(ABSTRACT TRUNCATED AT 250 WORDS)

Alpha-fetoprotein alterations in alcoholics with liver disease. V.A. Cooperative Study Groups.

Sera on 409 male alcoholics with liver injury were assayed for alpha-fetoprotein (AFP) as part of a VA co-operative study on the natural history and therapy of alcoholic liver disease. In 78% of the patients values below normal were observed and 42% had undetectable levels. Clinically the lowest AFP concentrations were observed in the more severely ill patients with the poorest 1 year survival. Furthermore, improvement in AFP was associated with improved survival. Correlation analysis showed a relationship of AFP to (1) visceral protein concentrations (i.e. albumin, transferrin, retinal binding protein); (2) variables related to hepatic fibrogenesis (i.e. Ito cell activity, quantitative estimates of fibrosis and Kupffer cell abnormalities); and (3) changes in immunoglobulin levels particularly IgG. These findings suggest that AFP is a good index of disease prognosis.

Sex steroid regulation of autoimmunity.

The immune response of males and females is not identical but instead has been shown to be dimorphic in its nature, with females generally demonstrating a greater overall response than males. This dimorphism extends to both the humoral and cell mediated systems and appears to be mechanistically based on the differences in type and concentration of sex steroids in males vs females. Furthermore, growth hormone and prolactin secretions which are different in males and females may also be partly responsible for the observed dimorphism. Because autoimmune disease results from a pathological perturbation of normal immune function, it follows that expression of these diseases will also demonstrate a dimorphic pattern. Examples of this autoimmune dimorphism include (but are not limited to) lupus, rheumatoid arthritis and multiple sclerosis with the two former more prevalent in females than males and the latter more severe during pregnancy. To explain autoimmune dimorphism it therefore becomes necessary firstly to describe the cellular and hormonal interactions found in normal immune regulation and thereafter extrapolate these to autoimmune phenomena.

Host response to mycobacterial infection in the alcoholic rat.

Animals, chronically treated with alcohol, were inoculated with mycobacteria (bacillus Calmette-Guérin, 10.2 x 10(6) organisms) into the spleen to produce a granulomatous hepatitis. Before infection, chronic alcohol ingestion was associated with a depressed skin test response to phytohemagglutinin, 71.7% of baseline (P = 0.009). Mycobacterial (bacillus Calmette-Guérin) infection stimulated phytohemagglutinin skin test response to 417% of baseline in controls and 299% in alcoholics (P less than 0.001). The hepatic granuloma response was altered with smaller but more numerous granulomas (mean +/- SEM, 81.2 +/- 1.5 microns2 of area with a frequency of 1.8 granulomas per field in alcoholics vs. 129.8 +/- 5.71 microns2 and 1.2 granulomas per field in controls; P less than 0.001). These changes were associated with a 10-fold increase in colony-forming units per gram of liver (54.5 +/- 18.2 in alcoholics vs. 5.6 +/- 1.83 in controls; P = 0.0006). This model offers precise parameters for host response to infection and indicates that alcohol significantly impairs the clearing capacity for mycobacteria from the liver.

Anabolic steroid effects on immune function: differences between analogues.

As an untoward effect of chronic anabolic steroid use, immunologic alterations may be induced. To evaluate this possibility five commercially available steroids with various types of structural differences were studied in male Sprague-Dawley rats. Animals were divided into five groups and treated with testosterone (Group 1), testosterone propionate (Group 2), testolactone (Group 3), oxandrolone (Group 4), and stanozolol (Group 5). Androgenic anabolic steroids were administered daily, subcutaneously dissolved in oil, at a dose of 1.1 mg/kg. Immune alterations were assessed by skin-test responses to phytohemagglutinin. After five days of treatment (1.1 mg/kg/day) a significant immuno-suppression was observed with all groups. However, by day 10, groups 3, 4, and 5 showed an immuno-stimulation. Using oxandrolone as the model stimulant, serum testosterone levels were significantly suppressed, while castration abolished the stimulatory effect. These observations indicate that immune alterations do occur with anabolic steroids which are immuno-suppressive when the steroid nucleus is intact and immuno-stimulatory with nuclear alterations. It appears that these changes are associated with altered gonadal testosterone release.

Nuclear progestin receptors in rat thymic tissue.

The thymus and its associated endothelial cells and lymphocytes act as an important immunological tissue. The endothelial cells of the thymus have been reported to synthesize cytoplasmic progestin receptor in response to estrogen priming. To measure nuclear progestin receptor, female rats were castrated and primed for 3 days with estradiol benzoate (30 micrograms/0.1 ml/d) and immediately before sacrifice injected subcutaneously with 0.2 mg of progesterone. By Scatchard plot analysis we found that specific progestin receptor (KA = 0.89 +/- 0.10 x 10(9) M-1) was present in the KCl-nuclear extract. The concentration of nuclear progestin receptor was found to be in the range of 312.6 +/- 49 fmole/g tissue (n = 9, 1 hour after progesterone injection) while the nuclear receptor was significantly reduced (approximately 44 fmol/g tissue) in the oil treated controls. This level verges on the limits of sensitivity for this assay. For cytoplasmic progestin receptor the concentration was 3.46 +/- 0.20 pmole/g tissue in oil treated controls (n = 14) and 3.36 +/- 0.20 pmole/g tissue in progesterone treated animals (n = 24). The KA of this thymic cytoplasmic progestin receptor was 1.35 +/- 0.06 x 10(9) M-1. By competition assay, the relative binding affinity of nuclear progestin receptor was: R5020 (a potent synthetic progestin) (100%), progesterone (9%), testosterone (0.56%), corticosterone (0.53%), estradiol-17 beta (0%). It is concluded that thymic reticuloepitheleal cells contain nuclear progestin receptor and this finding supports the hypothesis that progesterone, like other sex steroids may play a regulatory role in thymic cell function.