Effect of hydrocortisone on peripheral blood phagocytic cells under beta-adrenoreceptors blockade

The effect of hydrocortisone (50 mg/kg body wt i.p.) under beta-adrenergic receptors blockade (four subcutaneous injections of propranolol in single dose of 5 mg/kg body wt with 3 h interval) on phagocytic activity and oxygen dependent microbicidal activity in NBT-test of peripheral blood phagocytic cells in male Wistar rats was investigated. It was established that hydrocortisone stimulated neutrophil phagocytic activity through 6, 24 and 48 h after hormone injection and decreased oxygen-dependent microbicidal activity of phagocytic cells in NBT-test. Hydrocortisone in vitro (500 ng/ml) decreased neutrophil phagocytic activity that indicated on realization of stimulating effect of hydrocortisone in vivo through complex of other indirect mechanisms. Administration of hydrocortisone led to depression of eosinophil phagocytosis and lesser decrease in monocyte phagocytic activity. Hydrocortisone effects were significantly modified under blockade of beta-adrenoceptors that indicated on its mediation by endogenous catecholamines through modulation of beta-adrenoceptor expression.     

Reversible depression of the reticuloendothelial system by liposomes

The effect of various doses of different types (reverse phase evaporation vesicles and small unilamellar vesicles) of intravenously injected liposomes on reticuloendothelial activity, as measured by the blood clearance rate of intravenously injected carbon, was investigated. Also the effect of pretreatment with reverse phase evaporation vesicles on blood clearance and tissue distribution of a second dose of similar vesicles was determined. For all concentrations used reverse phase evaporation vesicles caused reduction in reticuloendothelial activity at least up to 4 h after injection. 24 h after administration the rate of carbon clearance returned to the control level. On the contrary small unilamellar vesicles did not block reticuloendothelial activity. Pretreatment with reverse phase evaporation vesicles (250 μmol/kg) caused an increased blood level and a decreased hepatic uptake of a second dose of the vesicles, injected 1 h after the first dose. This seems to be due to a depression of reticuloendothelial activity and not to a depletion of opsonins. Pretreatment with small unilamellar vesicles (250 μmol/kg) had no significant influence on the tissue distribution of a second dose of vesicles. Our results clearly indicate that reverse phase evaporation vesicles cause a reversible depression of reticuloendothelial activity and this depression seems to be induced by a saturation of reticuloendothelial cells with liposomes.     

Effects of cyclophosphamide and cortisone on the virus-immune response characteristics of thymocytes and the early reconstitution profiles of P → F1 chimeras

Thymocytes from normal adult mice that have been treated 1 or 2 days previously with a low dose of cyclophosphamide (30 or 40 mg/kg), hydrocortisone acetate (2.5 mg), or hydrocortisone succinate (5.0 mg) show an enhanced potential to generate vaccinia-immune cytotoxic T lymphocytes (CTL) when stimulated for 6 days in irradiated, virus-infected recipients. However, the capacity of thymocytes (though not of spleen cells) to develop such CTL activity is lost within 8 days of treatment with the depot drug, hydrocortisone acetate. In contrast, thymocytes from mice treated 8 days previously with hydrocortisone succinate show response patterns equivalent to those found for normal adults, with the increased response characteristic of recent corticosteroid treatment being recalled by giving a second dose 2 days prior to sampling. “Cortisone resistance” is thus both a function of the form of drug given, and the time of sampling. A large dose of cyclophosphamide (150 mg/kg) completely eliminates thymocyte responder potential within 2 days of treatment. This protocol, and the administration of 2.5 mg of hydrocortisone acetate (but not hydrocortisone succinate), serves to remove the radiation-resistant host cells which initially (14 days after bone marrow reconstitution) dominate the CTL response patterns of adoptively transferred thymocytes from P1 → (P1 × P2)F1 bone marrow chimeras. A smaller dose of cyclophosphamide (100 mg/kg) delays the emergence of the radiation-resistant host component in both thymus and lymph node, and skews the emerging CTL activity toward the donor.     

Effect of the peroral use of the antitumor antibiotic, carminomycin, on the immunological reactivity of the body of animals]

Carminomycin administered orally to mice for many times in doses of 2.5 and 1.25 mg/kg induced suppression of hemagglutinine production to sheep erythrocytes and formation of immunologically competent cells in the spleen of test animals. The content of DNA and RNA in the spleen of the test animals treated with carminomycin and sheep erythrocytes was somewhat lower than that in the control mice immunized but not treated with the antibiotic. Carminomycin prolongated the life time of the skin graft by 6.5 days as compared to that of the skin homotransplant in the control animals. The oral use of carminomycin in a dose of 2.5 mg/kg induced a statistically significant decrease in the absorption capacity of the cells of the reticuloendothelial system of the animals.     

Hydrocortisone induces an increase of amylase content in individual zymogen granules from rat pancreas

This study was performed to evaluate the effects of different doses of hydrocortisone (1, 10 and 25 mg/kg/day) administered for 1, 3 and 8 days on pancreatic enzyme storage in rats. The enzyme content in both pancreas homogenates and in individual isolated zymogen granules (ZGs) was measured using standard biochemical assays and flow cytometry, respectively. Hydrocortisone did not alter the total amount of pancreatic DNA but increased the pancreas enzyme content in a time-dose-dependent way. Amylase activity was significantly increased after hydrocortisone administration at day +8 when 10 mg/kg/day was used, and from the first day of treatment when 25 mg/kg/day was administered. A significant increase in trypsin activity was also observed in response to 25 mg/kg/day of hydrocortisone but only from the third day of treatment onwards. As compared with control rats, chronic administration of either 1 or 10 mg/kg/day of hydrocortisone did not alter significantly either the size or the percentage of the two ZG subpopulations (Z1 and Z2) identified in the pancreas by flow cytometry; in addition, no significant changes were observed in the mean amylase content per individual granule, although its mean concentration increased in rats treated with 10 mg/kg/day for 3 and 8 days. Nevertheless, when 25 mg/kg/day of hydrocortisone were administered for 1 and 3 days, a significant increase in the proportion of Z1 ZGs was observed, which may be related to the formation of new and smaller ZGs. When a very high dose of hydrocortisone (25 mg/kg/day) was used, an overall increase in the pancreatic enzyme content related to an increase in the mean amylase content per individual ZG was observed; this effect was apparent from the first day of treatment in the Z1 subset of ZGs and from day +3 in the Z2 subpopulation. Only a high concentration of hydrocortisone was able to alter the enzyme storage process in individual zymogen granules, but they maintain a normal enzyme load at lower hydrocortisone doses.     

Changes in the ultrastructure and fibrogenic activity of rat dermal fibroblasts as affected by various doses of hydrocortisone

By means of electron microscopical morphometry and populational analysis it has been stated that hydrocortisone acetate, injected subcutaneously twice a week in dose 5 mg/kg of the body mass, produces decrease in number of intensively collagen-producing fibroblasts and increase in the part of fibroblasts and destroying cells in population of fibroblasts only in young (2-week-old) animals. The dose 10 mg/kg produces similar changes both in young and in mature (2-month-old) animals. In the young animals given hydrocortisone in dose 5 mg/kg of the body mass, the mean summational area and extension of the granular endoplasmic reticulum membranes in the fibroblast section diminishes, the summational area of the mitochondrial section decreases in the section of one cell, and the derm with less thickness, in comparison with the derm of intact animals, is formed, while in mature animals, given hydrocortisone in a small dose, all the parameters mentioned do not significantly differ from the control. Hydrocortisone in dose 20 mg/kg decreases all quantitative parameters of dermal fibroblasts both in young and mature animals. The data of the correlative analysis give evidence on the presence of a strong positive connection between inhibition of the synthetic apparatus of fibroblast development under hydrocortisone effect and decrease of the derm thickness, forming during the postnatal period of ontogenesis.     

Effect of hydrocortisone on superoxide radical production by phagocytosing spleen cells

Superoxide radical production by mouse phagocytic spleen cells was shown to be essentially increased 2 hours following intraperitoneal injection of hydrocortisone acetate at a dose of 50 mg/kg body weight. The addition of hydrocortisone to the suspension of mouse spleen cells has resulted in linear dependence of hormone concentration in the incubation medium on the maximum rate of superoxide radical production. The mechanism of hydrocortisone stimulating effect on the activity of plasma membrane-located NAD(P)H-oxidase of phagocytic cells is being discussed.     

Cytochemical and ultracytochemical studies of peroxidase activity in rabbit blood granulocytes under hydrocortisone effect

Cytochemically peroxidase activity has been examined on the light optical and ultrastructural levels in blood granulocytes of the rabbits after a single (5 mg/kg) and multiple (1 and 5 mg/kg every 24 hrs during 4 weeks) administrations of hydrocortisone. Under electron microscope peroxidase activity was detected in the blood of intact rabbits into typical primary granules (TPG) and small polymorphic granules (SPG) of neutrophils as well as into specific granules of basophils sometimes in perinuclear space and GER channels. 6 h after hydrocortisone injection peroxidase activity in neutrophils increased, the reaction product in both kinds of cytoplasmic granules was electron denser than in the controls. After multiple hydrocortisone (1 mg/kg) administrations peroxidase general activity in granulocytes has not considerably changed, but the number of TPGs and SPGs was decreased in neutrophils. Multiple administrations of a higher dose of hydrocortisone (5 mg/kg) have induced peroxidase activity decreasing in neutrophils and a decrease in the number and electron density of TPGs and SPGs in them. In basophils there was a significant accumulation of the reaction product of high electron density in perinuclear space, in specific granules and GER channels. The conclusions has been drawn that a short-term raising of hydrocortisone level stimulates and prolonged hypercorticism inhibits peroxidase activity in neutrophils and, consequently, their function.     

Plasma immunoassayable ACTH levels during and after hydrocortisone infusion in patients with Cushing's disease.

The plasma ACTH responses to hydrocortisone infusion were compared in patients with Cushing's disease and primary adrenocortical insufficiency. In 4 patients with primary adrenocortical insufficiency, plasma ACTH levels were suppressed exponentially after administration of a relatively large dose of hydrocortisone (1.0 mg/kg/1.5 hr-3.0 mg/kg/2 hr). In patients with post-adrenalectomized Cushing's disease (4, bilateral; 1, unilateral), plasma ACTH suppression was delayed. Plasma ACTH levels, expressed as a percentage of the basal concentrations, were significantly less suppressed in patients with Cushing's disease than in patients with primary adrenocortical insufficiency 90 (p less than 0.05) and 120 (p less than 0.05) min after the beginning of infusion. When 0.5 mg/kg hydrocortisone was infused over a period of 1.5 hr, suppression was also delayed in Cushing's disease, and plasma ACTH levels were less suppressed in 4 patients with Cushing's disease than in 4 patients with primary adrenocortical insufficiency at 30 (p greater than 0.05), 45 (p greater than 0.05) 60 (p less than 0.05) min.     

Metallothionein in male reproductive organs of adrenalectomized and hydrocortisone-treated Wistar rats

Adrenalectomy resulted in an increase in metallothionein (MT) levels in testes, caput and cauda epididymis and prostate of rats but not in seminal vesicles where its levels decreased significantly. Inspite of administration of hydrocortisone, MT in testes, prostate (1.2 mg), caput (0.3 mg days 2, 8; 0.6 mg and 1.2 mg) and seminal vesicles (0.3 mg day 2, 4; 0.6 mg and 1.2 mg) remained increased. Thus adrenal insufficiency/hydrocortisone has no direct influence on MT levels. However, the increased levels of MT can be related to its ability to protect the cells from free radical damage caused by atrophy of reproductive tissues in adrenalectomised rats. Exogenously administered hydrocortisone to ADX rats resulted in return to ADX state as hydrocortisone metabolizes (half-life < 12 hr) and hence MT levels remained increased. The observations could provide a clue for the physiological functioning of the male reproductive tissue in a state of adrenal deprivation and hormonal supplementation.     

Changes in rabbit thymus lymphoid tissue after administration of pyrogenal and hydrocortisone]

After a single administration of pyrogenal (0.2 and 5 mkg/kg) and hydrocortisone (100 mg/kg) histological changes in the rabbit thymus have been studied and compared with the level of 11-oxycorticosteroids (11-OCS) in blood of the animals under investigation. Hydrocortisone, while producing a considerable rise in the level of 11-OCS, increases the number of degenerating cells, inhibits mitotic activity and decreases the amount of lymphocytes per stipulated area unit in the cortical substance. Changes produced in the thymus after pyrogenal administration are similar to those produced by hydrocortisone administration but are pronounce much weaker, that is connected with concentration of corticosteroids circulating in blood.     

Studies on L-arginase in developing rat small intestine, brain, and kidney. II. Effect of hydrocortisone and thyroxine

The influences of hydrocortisone and thyroxine on the developmental changes of arginase activity in intestine, kidney, and brain of suckling rats were studied. A single injection of hydrocortisone (50 mg/kg) into rats aged 9 days evoked premature increase of jejunal arginase activity due to precocious formation of arginase A4. Arginase A4 can be detected about 48 hr after hydrocortisone injection, whereas in intact rats the enzyme appears in the intestinal mucosa on the 19th-21st days of postnatal life. After hydrocortisone administration to rats aged 6 days, a similar pattern of arginase activity in jejunum was observed. Under the same conditions, the influence of hydrocortisone on kidney arginase was weaker. The hormone did not have any influence on the activity of brain arginase. Daily injection of thyroxine (2 mg/kg) to 6-day-old rats (for 6 consecutive days) caused a precocious increase of the arginase activity in intestine. Under the same conditions, only a slight increase of the arginase activity was observed in kidney, whereas in brain the activity was unaffected.     

The effect of a peat-based preparation on mitogen-induced proliferation of thymocytes in non-treated and hydrocortisone-suppressed mice.

The studies were carried out on Balb/c mice (5-6 weeks of age) treated with a peat-based preparation (PBP), administered i.p. once or four times at 24 h intervals at doses of 0.01; 0.1 or 1 mg/kg. Additionally, hydrocortisone was injected i.p. to selected mice at a single dose of 125 mg/kg. The results show that PBP temporarily enhances the proliferative capability of murine thymocytes stimulated in vitro with concanavalin A (Con A) and phytohemagglutinin (PHA). The effect of PBP depends on the number of subsequent doses, but does not depend on the dose applied. A single PBP administration does not affect the proliferative response of thymocytes to Con A and PHA. A single injection of PBP (doses from 0.01 to 1 mg/kg) does not change the number of thymic cells and weight ratio of this organ. Increased doses of subsequent PBP injections (0.01 and 0.1 mg/kg) do not affect the number of thymocytes, but temporarily increase the weight ratio of the thymus two days after the last injection. Administration of PBP prior to hydrocortisone prevents the suppressive effect of the drug on proliferative response of thymocytes stimulated in vitro with Con A and PHA, at the same time increasing the proliferative response of thymic cells to the two mitogens in relation to the control group (hydrocortisone-free). The effect of a single dose of PBP depends on the dose applied--the weakest preventive effect was observed at a dose of 0.01 mg/kg. An increase in the number of subsequent PBP doses, irrespective of a dose applied, prolongs the protective action of the drug on proliferative activity of thymocytes stimulated in vitro with these mitogenes. Moreover, the results obtained in the studies show that PBP partially prevents the suppressive effect of hydrocortisone, as the number of thymic cells and weight ratio of this organ drastically decreased. PBP accelerates regeneration of the thymus, but this depends on a dose applied and the number of subsequent doses. The result was the strongest and the fastest when PBP was injected four times at a dose of 1 mg/kg. It seems quite likely that the thymic regeneration due to PBP is connected with the effect of this drug on maturation and differentiation of thymic cells.     

Dependence of mononuclear infiltration of the liver on hepatocyte proliferation

Partial liver resection (two-thirds) performed in (CBA X C57BL)F1 mice 2-4 or 24 h after intravenous injection of 2 mg zymozan led to retardation of the formation of mononuclear infiltrates in the liver and the lung. In control sham-operated animals, the first signs of infiltration appeared on the 2nd, whereas in mice with partial liver resection ( PLR ) on the 5th day after zymozan -induced stimulation of liver macrophages. If mice underwent PLR 5 days after zymozan injection, the preformed mononuclear infiltrates experienced the reverse development. PLR did not abolish monocytosis which was observed after zymozan injection. On the other hand, when mice received hydrocortisone in a dose of 125 mg/kg, the zymozan -induced infiltration in the liver as well as monocytosis were blocked. It is assumed that depression of mononuclear infiltration in the liver and the lung after liver resection is linked with a specific effect of proliferating hepatocytes rather than with the stress-induced mobilization of glucocorticoids.     

Activity of some lysosomal enzymes in plasma and leucocytes of rabbits exposed to effect of retinol and hydrocortisone.

Observing activity of some lysosomal enzymes in blood serum and leucocytes of rabbits subjected to injection of 200,000 units of retinol and 25 mg of hydrocortisone/kg of body weight it was found that: 1. In the effect of retinol administration there was an increase in the activity AP, BGAL, BGLU, AspAT and lipase in blood serum after 72 hours and NAGL after 168 hours while in leucocytes BGAL and NAGL after 72 hours and AGAL after 168 hours. 2. As a result of hydrocortisone injection the activity of all the enzymes examined (except Ala-Na) in blood serum increased markedly already after 24-48 hours. 3. In leucocytes hydrocortisone caused a significant increase in the activity of AP, BGRD, NAGL, BGAL, AGAL and cathepsin D. 4. The glucose level in blood plasma decreased after 48 hours and 120 hours after hydrocortisone injection and 168 hours after retinol injection.     

Inhibitory action of microwave radiation on gamma-glutamyl transpeptidase activity in liver of rats treated with hydrocortisone

The influence of microwave irradiation on the activity of gamma-glutamyl transpeptidase (GGT) induced by hydrocortisone (HC) in the liver of rats was investigated. Animals were subjected to microwave irradiation (frequency 53.57 GHz, power density 10 mW/cm2 and 1 mW/cm2) during and after hydrocortisone (HC) treatment (20 mg/kg for 60 days). The results indicate that microwave radiation may block an inducible effect of HC on GGT activity in the liver of rats. This effect depends on the power density of millimetre microwaves.     

Cytogenetic activity of chemical compounds in adrenalectomized animals

Pyrimethamine, sodium salicylate or ethanol were administered to adrenalectomized rats 3 and 21 days after the operation. It is shown that cytogenetic effect in the operated rats is less pronounced, particularly 3 weeks after the operation. Adrenaline (0.2 mg/kg) increases the effect of chemicals on the chromosome apparatus, while hydrocortisone (50 mg/kg) and corticotropin (10 U/kg) decrease it.     

Immunological reactivity of the lung: VII. Effect of corticosteroids and cyclophosphamide on the Fc receptor function of alveolar macrophages

The effects of various in vitro and in vivo regimens of either corticosteroid or cyclophosphamide administration on guinea pig alveolar macrophages were studied. Corticosteroid- and cyclophosphamide-induced immunosuppression was assessed by the effect of drug administration on the capacity of alveolar macrophages to attach to and/or ingest antibody-coated sheep red blood cells (SRBC). In vitro hydrocortisone (up to 20 μg/ml) had no effect on either the binding or ingestion of antibody-coated SRBC. Two separate regimens of in vivo corticosteroids were given: a single dose of iv hydrocortisone (100 mg/kg), which is a short-acting soluble preparation, and sc doses of cortisone acetate (100 mg/kg for 7 days), which is a depot preparation resulting in sustained levels of plasma cortisol of the magnitude of that found for a brief period of time following iv injection of hydrocortisone. Both regimens resulted in similar degrees of peripheral blood lymphocytopenia and monocytopenia 4 and 24 hr, respectively, following injection. The regimen of hydrocortisone has previously been reported to have no effect on alveolar macrophage cytotoxic effector function in antibody-dependent cellular cytotoxicity (ADCC), whereas the cortisone acetate regimen markedly suppressed ADCC. In the present study, hydrocortisone had no effect on either the binding or ingestion of antibody-coated SRBC by alveolar macrophages. In contrast, cortisone acetate caused a marked decrease in both the binding and ingestion of antibody-coated SRBC. This suppressive effect was maximal at suboptimal concentrations of antibody on the SRBC and could be overcome by increasing the concentrations of anti-SRBC antibody. Alveolar macrophages from animals treated with daily cyclophosphamide (a regimen which suppresses ADCC) were capable of binding and ingesting antibody-coated SRBC normally. Thus, prolonged exposure to corticosteroids in vivo causes an alteration in membrane Fc receptor function of alveolar macrophages, which can explain this impaired ability to kill target cells. Since cyclophosphamide therapy did not interfere with the binding and ingestion of antibody-coated target cells, it is concluded that the impairment in killing of target cells by alveolar macrophages is not directly related to an alteration of Fc receptor function but to a defect in the actual killing process.     

Change in the absorptive capacity of macrophages from different organs after administration of hydrocortisone

Two, twenty-four and 48 h after hydrocortisone treatment in a dose of 125 mg/kg bw the blood clearance rate for colloidal carbon particles in rats turned to be 2, 2.1. and 1.6 times less whereas that for 51Cr-SRBC in CBA mice 2.1, 2.2 and 1.7 times less as compared to untreated controls. Within 24 and 72 h after hormone injection the efficacy of red blood cell uptake by Kupffer cells decreased 1.35 and 1.8 times whereas the similar uptake by lung or spleen macrophages changed but insignificantly and that by bone marrow cells was even greater than in controls. Toward the 5th day after zymosan treatment the uptake capacity of Kupffer cells was the greatest whereas the plasma 11-OHCS content was 1.3-fold less versus the control values.     

Effects of the Ay gene on susceptibility to hydrocortisone fetotoxicity and teratogenicity in mice

Effects of the Ay gene, a coat color gene, on susceptibility to hydrocortisone fetotoxicity and teratogenicity were investigated by using the congenic strain of C57BL/6-Ay (Ay/a) which had been maintained by repeated back-crosses of the Ay gene to the C57BL/6 (a/a) background. Matings were conducted as follows (female x male): group I, a/a; group II, a/a x Ay/a; and group III, Ay/a x a/a. Pregnant females were subcutaneously given daily doses of 0, 12.5, 25, or 50 mg/kg of hydrocortisone on days 10-13 of pregnancy. On day 18 of pregnancy, fetuses were sexed, weighed, and examined for external abnormalities. In group I, the mean fetal weight was significantly decreased at a dose of 25 mg/kg or more. The incidences of cleft palate were 3.2 and 22.7% at 25 and 50 mg/kg, respectively. In group II, in which half of the fetuses were expected to carry the Ay gene, the mean fetal weight was decreased significantly at 12.5 mg/kg or more. The incidence of cleft palate in group II at 50 mg/kg was 44.2%, which was significantly higher than that in group I. In group III, in which maternal mice as well as half of their fetuses carried the Ay gene, a decrease in the mean fetal weight was greater than in group II. In addition, the mean percentage of fetal resorptions was significantly increased at 50 mg/kg. The incidence of cleft palate in group III was significantly increased at 25 mg/kg (10.5%) when compared with those in groups I and II. These results indicate that the Ay gene may be associated with susceptibility to hydrocortisone fetotoxicity and teratogenicity in mice.