Effect of Alternate-Day Hydrocortisone Therapy on the Immunologically Immature Rat. I: Effect on Blood Cell Count, Immunoglobulin Concentrations, and Body and Organ Weights

Abstract

The effect of 400 mg/M2/day of hydrocortisone, given alternatively from day 7 to day 19, was studied in the immunologically immature rat, a steroid-sensitive species. Animals, sacrificed 2 days following the completion of treatment, suffered from an underweight thymus and spleen, leucocytosis, and peripheral lymphocytopenia, probably not due to redistribution of lymphocytes from blood to tissues. In addition, a significant decrease in serum IgM concentration, reflecting a deficit in primary immune response, was evidenced. Although the percentage of lymphocytes returned to normal in rats sacrificed 23 days after treatment, an overweight thymus and spleen and persistent leucocytosis may reflect a compensatory overactivity of the developing immune system. In contrast, serum IgM concentration increased, but to a value less than normal. An indirect effect of hydrocortisone on lymphocytes through its action on thymus, as well as a direct effect on B cells, is suggested. Unlike humans, alternate-day steroid therapy delayed the normal growth pattern of rat, with a defective rate of growth only during the treatment period.

Electron Microscopic Study on the Effect of Alternate-Day Hydrocortisone Therapy on Lymphocyte Populations in Rat Spleen and Lymph Nodes

“…However, medium-sized lymphocytes of the marginal zone of the white pulp of the spleen and, apparently, of the outer cortex of the mesenteric lymph nodes in 21-day-old hydrocortisone-treated rats were depleted of cytoplasmic organelles. Hydrocortisone appeared to reduce the metabolic and secretory activities of medium-sized lymphocytes and to depress protein synthesis, which is consistent with the resultant decrease in IgM production reported in a previous study (9).…”

“…x 18,500. on these small lymphocytes. Rather, these findings are consistent with a depletion in the supply of T lymphocytes to the spleen resulting indirectly by the lytic effects of hydrocortisone upon the thymus (7,9).…”

“…Uranyl acetate and lead citrate. x 15,500. IgM by these animals was increasing although the concentration was below that of controls (9). It may be that the 3-wk period from the cessation of the therapy to the time of sacrifice was insufficient to fully reverse the injury.…”

Effect of long term Administration of hydrocortisone on some organs in females rats

“…Per spleen, an absolute reduce of cells carrying immunoglobulin receptors on the surface as determined by immunofluorescence was found and a smaller in cells reduce with theta-antigen (Vischer, 1972). El-fouhil and Turkall, (1993) reported in the study of hydrocortisone appeared to decrease the metabolic and secretory activities of medium-sized lymphocytes and to compresses protein synthesis, which is consistent with the resultant decrease in IgM production.…”

“…Eighteen of female rats (Rattus norvegicus) were used in the present study. Rats supplied from the animal house of Biology department, Science collage, Thi-Qar university, Iraq with weights ranging from 200 to 250 g. We used Hydrocortisone sodium succinate (100mg) supplied in rubber-capped vials, each was dissolved in 2ml of sterile distilled water and were administered by intra-peritoneal injection for two months an alternate day injection (EL-fouhil and Turkall, 1993) according to the determinate doses of each group. Animals were divided into three groups (6 for each group).…”