A study of the subacute toxicity of prednisolone, methylprednisolone, and triamcinolone in dogs

Renal and Hematologic Comparative Effects of Dissociated Agonist of the Glucocorticoid Receptor and Prednisone in Dogs With and Without Food Restriction

Glomerulopathy and body weight gain were noted after chronic oral administration of a novel nonsteroidal dissociated agonist of the glucocorticoid receptor compound, fosdagrocorat, to beagle dogs fed an ad libitum diet. To further investigate the role of diet and treatment with either fosdagrocorat or the glucocorticoid comparator, prednisone, on renal safety, a 13-week investigative study was conducted in beagle dogs. Renal histopathology, clinical chemistry, urinalysis, glomerular filtration rate (GFR), body weight, heart rate, blood pressure (BP), and hematology were investigated in restricted- and ad libitum-fed dogs administered prednisone (2.2 mg/kg/d), fosdagrocorat (5 mg/kg/d), or vehicle for 13 weeks. Glomerulopathy was primarily observed in fosdagrocorat- and prednisone-treated ad libitum but not in feed-restricted or ad libitum vehicle-treated dogs. Kidneys in dogs from the prednisone-treated ad libitum had the greatest incidence and severity of tubular degenerative changes. Increased urine volume and decreased urine-specific gravity were present in prednisone- and fosdagrocorat-treated dogs, regardless of diet. These changes were not associated with consistent changes in GFR. Fosdagrocorat or prednisone treatment ad libitum dogs had the greatest increase in body weight gain. Sporadic changes in systolic and diastolic BP were noted in fosdagrocorat- and prednisone-treated groups. Significant reductions in serum cortisol and absolute eosinophils were noted in both ad libitum- and restriction-fed prednisone- and fosdagrocorat-treated dogs. In conclusion, prednisone-treated dogs fed ad libitum had greater glucocorticoid-induced renal effects than those dosed with fosdagrocorat.

Diuretic effect of some adrenocortical steroids in the rat

Cortisone, hydrocortisone and some of their Δ1- and fluorinated analogues have a pronounced diuretic effect in the rat; this is accompanied by increased urinary excretion of both Na+ and K+. Diuresis is maximal some 4 hr after oral administration, and in acute studies, the diuretic potency of some of the newer corticosteroids exceeds 100 times that of chlorothiazide.

Review of the toxicology of beclomethasone dipropionate

This paper reviews the published toxicity of beclomethasone dipropionate (BDP). BDP is a synthetic glucocorticosteroid which has a powerful local anti-inflammatory effect but little systemic action. It has been developed for both dermatological and inhaled applications. LD50 values and other acute studies indicated low toxicity. Findings published for repeat dose and reproductive toxicity studies embraced the known range of metabolic and physiological effects of glucocorticoids. For repeat dose studies, these included reduction in body weight gains, cushingoid syndrome in dogs, reductions in the numbers of lymphocytes and the weights of the tissues connected with the immune system, and hepatic glycogen deposition and fatty liver changes. In reproductive studies, there was an increase in the prevalence of cleft palate in mice and rabbits and in the number of dead foetuses, and ossification was retarded. Despite the route of administration, there was a general similarity of effects within and between species. All observations were characteristic of synthetic glucocorticoids and related to the intrinsic effects of these drugs.

Prednisone-induced morphologic and chemical changes in the liver of dogs

Glucocorticoid treatment in dogs is known to cause hepatocellular swelling due to accumulation of cytoplasmic compounds which variably have been identified histochemically as fat, glycogen, or water. In the present study changes in dog liver, after treatment for 15 days with two different doses of oral or intramuscular prednisone, were examined using histological, histochemical, and ultrastructural techniques as well as quantitative chemical analysis. Thirty mongrel dogs were divided into two control groups and three treatment groups of six dogs each. Dogs which received prednisone orally at 1.2 mg/kg body weight/day, or 4 mg/kg body weight/day, respectively, or received intramuscular prednisone injections of 4 mg/kg body weight/day had hepatomegaly due primarily to hepatocellular accumulation of glycogen. Compared to controls, no changes in the hepatic water concentration were observed, whereas the relative amounts of liver fat were decreased slightly and those of protein were decreased markedly. Hepatocellular glycogen could be demonstrated histochemically in tissues fixed in absolute alcohol, but not in tissues treated with aqueous fixative, such as 10% buffered formalin or Bouin's solution. Glycogen deposition occurred predominantly in the midzone of hepatic acini. Affected hepatocytes varied in size and shape. The most severely affected cells were enlarged five to ten fold with glycogen occupying most of the cytoplasmic space restricting the mitochondria, endoplasmic reticulum, and other organelles to a narrow zone around the cell periphery and the nucleus. It was concluded that treatment with prednisone causes hepatomegaly due to glycogenosis in the dog.