Diaphragm atrophy and weakness in cortisone-treated rats

Despite frequent therapeutic use, the potential of corticosteroids to produce respiratory muscle myopathy is unknown. We studied effects of chronic steroid treatment on diaphragm mass and function. Eleven Sprague-Dawley rats were treated with cortisone acetate (100 mg.kg-1.day-1 im) for 10 days. Controls (injected with vehicle) included 11 freely eating rats and 11 animals pair fed to match food intake of cortisone rats. Steroid treatment depressed body weight 30% compared with controls. Mass of diaphragm, gastrocnemius, and extensor digitorum longus showed significant atrophy (30%); heart and soleus were unaffected. Isometric contractile properties of costal diaphragm strips were studied in vitro using direct stimulation. The force-frequency relationship was markedly depressed by steroid treatment, both at low and high frequencies. However, force developed per unit cross-sectional area was similar among all three groups, as were twitch characteristics. When stimulated every minute, forces developed by control strips fell progressively, whereas the forces of cortisone-treated strips remained unchanged. When stimulated every 5 s, the fall in force was not different between groups. We conclude that cortisone weakened the diaphragm by decreasing muscle mass but made the diaphragm more resistant to one form of fatigue in vitro.

The effect of immunosuppression on resistance to Rhodococcus equi in mice

Rhodococcus equi, a natural pathogen of horses, produces lesions in mice following experimental infection. The effect of various immunosuppressing agents on the sequential development of these lesions has been assessed by measuring the growth of R. equi following intravenous or intranasal challenge and by histological examination. Cyclophosphamide treatment of mice, challenged intranasally, resulted in the development of lesions not unlike that seen in experimental and natural infection in foals. Cortisone acetate also impaired bacterial clearance from the lungs and affected the accumulation of mononuclear cells at infective foci. Most of the agents chosen to impair macrophage function failed to affect the resistance of mice to R. equi. Carbon, carrageenan and silica failed to alter significantly the growth kinetics of R. equi. Dextran sulphate depressed the rate of pulmonary clearance of organisms and affected the ability of animals to eliminate R. equi following rechallenge. Overall, these results support other evidence that cell mediated immunity is involved in host resistance to R. equi and that activated macrophages play a role in acquired immunity to this organism.

Corticosteroid sulfates in fetus plasma

The sulfates of deoxycorticosterone (DOCS), corticosterone (BS), cortisone (ES) and cortisol (FS) were radioimmunoassayed in umbilical vein blood plasma samples collected in 97 fetuses between 19 and 32 weeks of gestation after extraction and chromatography on Sephadex LH 20 columns. While DOCS and BS displayed a decreasing pattern until 27-28 weeks, FS and ES did not show important variations throughout the period considered. All sulfates, excepted BS, increased at 29-30 weeks but this rise was only significant for FS and ES. Thereafter BS significantly increased while no significant difference could be displayed for the three others. In view of the difference between the patterns of 17-deoxy- and 17-hydroxycorticosteroids, one can speculate that, during this period of pregnancy, a shift in steroid biogenesis might occur towards a more important production of cortisol. DOCS was correlated with BS and with FS but not with ES. FS was correlated with the three other sulfates and with unconjugated F. ES was correlated with BS and FS but not with DOCS or unconjugated E. The significance of these correlations are discussed according to the origin and the metabolic interrelationships of the four steroid sulfates and unconjugated F and E.

Cortisone cure of the eyelid closure defect in lidgap-Stein fetal mice: a dose-response and time-response study as a test of the hypomorph hypothesis for the lidgap alleles

The lidgap-Stein mutation is one of a series of alleles that cause the birth defect open eyes in mice. Previously it was known that cortisone administered during pregnancy prevents the defect in some lidgap-Stein fetuses. In this study, the hypothesis that lidgap-Stein is a hypomorph of effect intermediate between that of its alleles lidgap-Miller (least abnormal) and lidgap-Gates (most abnormal) was tested in a dose-response, time-response, and scanning electron microscopic study. Cortisone produced a response at doses of 20-80 mg/kg, with maximum cure of 30% in right eyes, 24% in left eyes, and 13% bilaterally. There was significantly more response in right than in left eyes. The response was slight at doses of less than 20 mg/kg and dropped to zero at the highest dose of 120 mg/kg. Treatment on days 13 or 14 gave the maximum response, with little or no response to treatment on days 10, 11, 12, 15, or 16. Severity of defect, measured as the size of gap in open eyes on day 18, was not reduced as the frequency of open eyes was reduced; most unclosed eyes remained wide open. The much lower level of maximum bilateral response to cortisone in lidgap-Stein (13%) than in lidgap-Miller (94%) is entirely compatible with the hypomorph hypothesis.

[Various immunologic indices in primary chronic adrenal insufficiency]

Patients with primary chronic adrenal insufficiency (PCAI) in decompensation demonstrated a decrease in the total level of blood immunoglobulins, in particular IgG, with the normal level of B-lymphocytes. A decrease in IgG and an increase in IgA content was noted in the eucorticoid state; relative and absolute lymphocytosis determined by an increase in T- and B-lymphocytes was also noted. In overdosage of cortisone acetate the total number of immunoglobulins was normal, but IgA was raised and IgG lowered. The number of B-lymphocytes was significantly elevated. The number of T-lymphocytes was within normal but an increase in the level of T-suppressors was noted.

Fungus dose-dependent primary pulmonary aspergillosis in immunosuppressed mice

We report on a model of primary pulmonary aspergillosis occurring after intranasal instillation of concentrated suspensions of conidia of Aspergillus fumigatus in immunocompromised mice. Unconcentrated suspensions of inoculum contained ca. 2 x 10(7) conidia per ml (1x). These suspensions were concentrated by centrifugation, adjusted to give ca. 2 x 10(8) (10x) or 2 x 10(9) (100x) conidia per ml, and delivered in 30-microliters droplets to the nares of anesthetized mice. Mice were untreated or injected with cortisone acetate (CA) or cyclophosphamide (CY) in various dosage regimens. It was not possible to obtain mortality of more than 50% with sublethal immunosuppressive treatment and 1x fungus. In contrast, mortality followed a fungus dose response in mice receiving sublethal immunosuppression with either CA or CY. Mortality rates of up to 100% were obtained with 100x fungus and a single dose of CY (200 mg/kg) or CA (250 mg/kg) or three alternate doses (125 mg/kg per day) of CA prior to infection. This model is applicable to the study of acute, fatal primary pulmonary aspergillosis and chemotherapy trials.

Rats stunted by high-dose glucocorticoid treatment are capable of undergoing catch-up growth after fasting

Experiments were carried out to test the hypothesis that permanent growth retardation after glucocorticoid-induced growth suppression is due to an alteration of a central set point for target size rather than an inability of peripheral tissues to carry out catch-up growth. Rats were injected subcutaneously with saline, as controls, or with cortisone acetate, 1 mg/25 g body wt/d, for 4 d, beginning at 37 d of age. The treated animals were submitted to acute fasting for 48 h, beginning at 47 d of age, after which they were allowed to feed ad libitum. Cortisone treatment significantly stunted body wt, tail length, and tibia length. During recovery after fasting, both the cortisone-treated and the saline-injected rats exhibited catch-up growth in body wt and tibial length. In other rats killed at different time intervals during recovery after cortisone treatment, only, there was no pattern of catch-up growth in tibia length. There was no difference in tibial epiphyseal width between fasted and nonfasted rats within the saline- or cortisone-treated group. The findings demonstrate that rats that are permanently stunted by high-dose glucocorticoid treatment retain the capability for catch-up growth in both soft and skeletal tissues. The data support the hypothesis that catch-up growth is regulated by a central control with a mechanism (set point) for setting target size of the body. Stunting resulting from glucocorticoid treatment may be the result of a reset of the putative set point.

Secondary adrenal insufficiency manifested as an acute febrile illness

High fever occurred in a 30-year-old woman five weeks after transsphenoidal hypophysectomy for a pituitary adenoma. Extensive investigation failed to reveal any evidence of infection, and the clinical findings suggested the fever to be a manifestation of steroid withdrawal. Either suboptimal dosage of corticosteroid replacement therapy or omission of such therapy in adrenal insufficiency must be considered in the differential diagnosis of enigmatic postoperative fever.

Decreased yield of Pneumocystis carinii from cortisonized rats

Thirty-five male Sprague-Dawley rats were divided into 3 groups, including 1 control and 2 experimental groups, in order to compare the efficacy of using cortisone acetate alone or in addition to intranasal inoculation of Pneumocystis carinii organisms for the purpose of inducing acute P. carinii pneumonia. The presence of P. carinii was monitored in nasal secretions on a weekly basis and in lungs at autopsy. Titers of IgG antibody were also monitored by enzyme-linked immunosorbent assay. No rat receiving cortisone acetate injections alone and only 2 of the rats receiving both cortisone and intranasal inoculation of P. carinii organisms showed Pneumocystis organisms in the lungs. However, Pneumocystis cysts did appear in the nasal secretions of 3 of the 5 control rats, all 8 rats receiving cortisone acetate injections only, and 12 of 18 rats receiving both cortisone acetate injections and an intranasal inoculum. IgG titers of both cortisonized groups remained less than 1:4 throughout the course of the experiment. The titer of the control group increased from negative to 13 (geometric mean).

Growth hormone deficiency in patients with idiopathic adrenocorticotropin deficiency resolves during glucocorticoid replacement

Glucocorticoids (GC) have stimulatory effects on GH secretion in vitro and suppressive effects when administered in pharmacological amounts in vivo. We studied six patients with ACTH deficiency and severely impaired serum GH responses to insulin tolerance tests and arginine infusion tests. All patients underwent the same tests during GC replacement while receiving cortisone acetate in doses ranging from 12.5-25 mg/day. The three patients with idiopathic ACTH deficiency and no evidence of pituitary mass lesions had impaired GH secretion, which returned to normal during GC replacement. In contrast, the three patients with ACTH deficiency and hypothalamo-pituitary mass lesions detected by a computed tomography scan had impaired GH secretion during GC replacement therapy. Our data indicate that in patients with idiopathic ACTH deficiency, an impaired GH response to stimuli reversible during GC replacement therapy may be the functional consequence of the low levels of circulating cortisol. We conclude that physiological serum cortisol levels are necessary for normal serum GH responses to provocative stimuli in man.

Effects of hypercortisolemia and diabetes on skeletal muscle insulin receptor function in vitro and in vivo

Activation of skeletal muscle insulin receptor tyrosine kinase in vitro and in vivo was studied in two rat models of insulin resistance: insulinopenic diabetes and hypercortisolemia. In control rats, intravenous insulin administration resulted in dose-dependent in vivo activation of the muscle insulin receptor kinase towards histone H2b. Half-maximal and maximal activation were observed 5 min after injecting 0.1 and 0.5 U insulin/100 g, respectively. Diabetes (7 days) induced with streptozotocin did not affect insulin binding affinity of solubilized muscle receptors but depressed receptor kinase activation in vivo by 52 or 40% after intravenous insulin administration (0.1 or 2 U/100 g, respectively). Cortisone treatment (5 days) resulting in weight loss, hyperglycemia, and hyperinsulinemia did not affect the number, insulin binding affinity, or kinase activity of solubilized receptors activated with insulin in vitro or in vivo. It is concluded that impaired insulin receptor tyrosine kinase activation was demonstrated in vivo in rats with insulinopenic diabetes and that glucocorticoid-induced insulin resistance probably reflects postreceptor defect(s) in muscle.

Corticosteroids suppress cyclooxygenase messenger RNA levels and prostanoid synthesis in cultured vascular cells

Prostacyclin synthesis by cultured vascular smooth muscle cells was inactivated by aspirin. Recovery required serum factors replaceable by EGF plus TGF-beta and was blocked by cycloheximide but not by actinomycin D. Recovery of cyclooxygenase activity was prevented by preincubation with dexamethasone (0.1 to 2 microM), which also suppressed basal enzyme activity by up to 70%. A full length 2.8 Kb cDNA hybridization probe for human cyclooxygenase identified a cyclooxygenase messenger RNA of approximately 2.8 Kb in these cells. Cyclooxygenase mRNA levels were enhanced by EGF/TGF-beta, but suppressed completely by corticosteroids. It is concluded that inhibition of prostanoid synthesis by corticosteroids is mediated by suppressing cyclooxygenase messenger RNA. These observations provide a new molecular mechanism for the anti-inflammatory activity of the corticosteroids.

Determination of apolipoprotein A-I synthesis in intestinal explants from fetal and neonatal rats

The ability of rat intestine and liver to synthesize the main constitutive apoproteins of HDL (apolipoproteins (apo) A-I, A-IV and E) was studied by incorporation of [3H]leucine in vitro at different stages of perinatal life. In both organs, apoprotein synthesis was barely detectable at day 18 of gestation; it was initiated 2 days before the end of gestation. Apo A-I synthesis leveled off at birth in the intestine but kept increasing in the liver during suckling. Intestinal apo A-IV and hepatic apo E synthesis became stable 5 days after birth. Hormonal determination of apo A-I synthesis was examined at different ages in jejunum cultured for 48 h in vitro in the presence of effectors. The addition of dexamethasone to the culture medium was without effect on intestine explanted either at day 18 of gestation or at different postnatal ages (0, 2 and 5 days), but induced the specific stimulation of apo A-I synthesis at day 20 of gestation. At this stage, triiodothyronine alone was ineffective, whereas it enhanced the dexamethasone-induced stimulation. Apo A-I synthesis remained unaffected by insulin alone or combined with the glucocorticoid. Administration of cortisone acetate to pregnant rats from day 14 of gestation onwards resulted in a stimulation of apo A-I synthesis only when it was prolonged after the 20th day of gestation. No effect of dietary substrates could be obtained in vitro. It is concluded that glucocorticoids specifically potentiate prenatal apo A-I synthesis in the rat intestine but that their action is limited to the days immediately preceding birth. They cannot induce early maturation nor stimulate existing synthesis.

Complete estrogen blockade with buserelin and aminoglutethimide for advanced breast cancer: a phase I-II study with long-term hormonal correlations

We treated 21 patients with advanced breast cancer with buserelin, aminoglutethimide and cortisone acetate in an attempt to obtain a complete estrogen blockade both in premenopausal and postmenopausal patients. Ten patients (47%) obtained an objective response without any relevant side-effects. Dealing with hormonal data, it must be outlined that serum testosterone levels decreased significantly in postmenopausal patients, suggesting a possible explanation for the activity of luteinizing hormone-releasing hormone analogue in this group of patients.

Hepatic Na,K-ATPase development in the rat

The development of the enzyme Na,K-ATPase was studied in hepatic tissue from Sprague-Dawley rats at 18-20 days of gestation, 1, 3, 5, 7, 14, 21, and 30 days, and young adulthood (45 days). A developmental pattern was demonstrated for total and membrane-associated Na,K-ATPase activity. The activity in tissue homogenate, expressed per gram tissue, increased from late fetal life, 43.4 +/- 1.3 mumol Pi g liver-1 h-1, until 21 days of age, when an adult level of 187.3 +/- 19.6 mumol Pi g liver-1 h-1 was attained. A less pronounced ontogenic pattern was observed when enzyme levels were expressed as specific activity per milligram protein. The activity profile in a crude membrane preparation was similar. The potential for stimulation of enzyme activity by glucocorticoids was studied in 11-day-old animals injected with cortisone acetate (10 mg 100 g body weight-1) for 3 days. Enzyme specific activity was inducible: Specific activity was greater in cortisone-treated animals, 1.794 +/- .043 mumol Pi mg protein-1 h-1, versus controls, 1.258 +/- 0.043 mumol Pi mg protein-1 h-1 (p less than 0.01). We postulate that this developmental pattern for hepatic Na,K-ATPase activity may be a reflection of, or a contributing factor in, the ontogeny of sodium-dependent hepatic transport, such as that for bile salts.

Control of IGF-II mRNA levels by glucocorticoids in the neonatal rat

Insulin-like growth factor-II (IGF-II) is thought to be a major growth factor during fetal and neonatal development. Levels of IGF-II mRNA fall dramatically in the liver - the major site of endocrine production - between 18 and 20 days post-natally. No information concerning the control of gene expression post-natally has hitherto been available. Using Northern blotting and in-situ hybridization, we show here that cortisone acetate rapidly extinguishes IGF-II mRNA expression in the neonatal rat liver. The effect at putative autocrine/paracrine locations such as skeletal muscle and choroid plexus is much less marked or absent. The repression by cortisone acetate is discussed in the light of the available IGF-II gene sequence.

The sulfated polysaccharide-peptidoglycan complex potently inhibits embryonic angiogenesis and tumor growth in the presence of cortisone acetate

In combination with cortisone acteate, the sulfated polysaccharide (SP)-peptidoglycan (PG) complex produced by an Arthrobacter species was found to inhibit both embryonic angiogenesis of chick chorioallantoic membrane (CAM) and growth of solid Sarcoma 180 tumor in mice. Three fractions obtained from the SP-PG complex by gel filtration showed a great difference in the inhibitory effect on angiogenesis of the CAM, whereas in ex vivo study such a difference was reduced. Of the three fractions, SP-PG-L having the lowest molecular weight and peptidoglycan content exhibited the highest antiangiogenic and antitumor activities, even higher than those of heparin. Neither desulfation nor sulfation of the SP-PG complex greatly affected the antiangiogenic activity, and dextran sulfates and mannoglucan sulfates were lacking the activity. This suggested that glycosyl sequences of sulfated polysaccharides are more important for the activity, rather than content or intramolecular distribution of sulfate groups.

Syndrome of apparent mineralocorticoid excess. A defect in the cortisol-cortisone shuttle

The first adult case of 11 beta-hydroxysteroid dehydrogenase (11 beta-OHSD) deficiency is described. The impaired conversion of cortisol to cortisone (indicated by urinary cortisol and cortisone metabolites and failure to metabolize 11 alpha-[3H]cortisol to [3H]H2O), was associated with hypertension, hypokalemia, and suppression of the renin-angiotensin-aldosterone system. When established on a fixed Na+/K+ intake, dexamethasone, given orally, produced a natriuresis and potassium retention. Plasma renin activity became detectable. When hydrocortisone (10 mg daily s.c. for 4 d) was added, there was marked Na+ retention, a kaliuresis (urinary Na+/K+ falling from 1.2 to 0.15), with suppression of plasma renin activity and an increase in blood pressure. These changes were also seen with the subject on no treatment. Conversion of cortisone to cortisol was not affected. These results suggest that cortisol acts as a potent mineralocorticoid in 11 beta-OHSD deficiency. The major site for the oxidation of cortisol to cortisone is the kidney. In this patient congenital deficiency of 11 beta-OHSD results in high intrarenal cortisol levels which then act on renal type I mineralocorticoid receptors. This condition can be treated with dexamethasone, which suppresses cortisol secretion and binds to the type II glucocorticoid receptor. We suggest that 11 beta-OHSD exerts a critical paracrine role in determining the specificity of the type I receptor. In the normal state cortisol is converted by 11 beta-OHSD to cortisone which thus allows aldosterone to bind preferentially to the type I receptors in the kidney and gut. In this patient deficiency of 11 beta-OHSD results in high intrarenal cortisol concentrations that then bind to the type I receptor.

Effect of immunosuppression on survival and growth of cartilage produced by transplanted allogeneic epiphyseal chondrocytes

Strong short-term immunosuppression improved survival of cartilage formed by transplanted allogeneic epiphyseal chondrocytes in mice. The agents tested were cortisone acetate (CA), cyclophosphamide (CY), procarbazine (PCH), and antithymocyte serum (ATS). Their effect on syngeneic grafts was examined morphologically and histomorphometrically. In untreated recipients, chondrocytes formed cartilage nodules that underwent endochondral ossification. Except for high repetitive doses of CY, none of the other agents interfered with normal cartilage formation. However, all agents affected endochondral ossification. In the allogeneic system, the effect of immunosuppression was examined morphologically and by evaluation of specific humoral and cellular antigraft immunity. Allogeneic chondrocytes evoked a strong immune response in untreated mice, and cartilage was gradually destroyed by infiltrating cells. Endochondral ossification did not occur in this system. Neither agent given alone exerted a marked, long-lasting protective effect upon the graft. However, combined treatment with ATS and PCH inhibited immune response and completely prevented infiltrate formation and allowed endochondral ossification similar to that in the syngeneic control. Although some weak signs of antigraft immunity were seen after six weeks, it is possible that they were due to secondary exposure of antigen-bearing chondrocytes in the course of endochondral ossification.

An alternative protocol for the medical management of canine pituitary-dependent hyperadrenocorticism

As an alternative to the o,p'-DDD treatment aimed at the selective destruction of the adrenal cortices, the authors have introduced a protocol aimed at the complete destruction of the adrenal cortices. It consists of a longer period of daily treatment with o,p'-DDD and lifelong substitution for primary hypoadrenocorticism. The results obtained in 41 dogs, with a minimum follow-up period of one year, indicate that this approach has advantages over lifelong maintenance therapy with o,p'-DDD.

Reverse-phase liquid chromatographic determination of dexamethasone acetate and cortisone acetate in bulk drug substance and dosage forms: collaborative study

A reverse-phase liquid chromatographic method for determination of dexamethasone acetate and of cortisone acetate was subjected to an interlaboratory study by 8 collaborators for each steroid acetate. Bulk drug substance, suspensions, and tablets were assayed. Bulk drug or dosage form is dissolved in an acetonitrile-buffer mixture and analyzed by an external standard method. The steroid acetate is resolved from extraneous components by reverse-phase chromatography and detected at 254 nm. The sample solutions are stable for at least 72 h. For dexamethasone acetate, coefficients of variation were 0.9 and less than or equal to 3.1% for the bulk drug substance and the suspensions, respectively. For cortisone acetate, coefficients of variation were 0.7% for bulk material, less than or equal to 2.0% for suspensions, and less than or equal to 2.5% for tablets. All dosage forms were commercial formulations. The 2 methods have been adopted official first action.