Comparative Study Between The Effect Of Dexamethasone And Loratadine On The Histology Of Some Lymphasone And Loratadine On The Histology Of Some Lymphoid Elements Of Rabbits:

Ayman Mohamed Hasan Mousa

The present study was conducted on 120 male rabbits to probethe effect of dexamethasone and loratadine administration in thedose of 0.09mg/lOO gm of rabbit’s body weight/day orally in thesyrup form for two weeks on the structure of the mesenteric lymphnodes and the bone marrow lymphocytes in 3 different ages.The animals were classified _into 3 different age groups;namely, group I (young age of 4 weeks), group II (adult age of9months), and group III (old age on years). Each group was formedof40 male rabbits and subdivided into other 3 subgroups.• Subgroup A was the control subgroup formed of 10 rabbitsthat were administered distilled water.• Subgroup B was the dexamethasone subgroup formed of 15rabbits that were administered dexamethasone.Subgroup C was the loratadine subgroup formed of 15 rabbitsthat were administered loratadine.Histological sections were stained with H & E to study thegeneral structure of the mesenteric lymph nodes and to measure thesize of the lymphoid follicles and their germinal centers which areindicators of the activity of lymph node and their lymphocyteproliferation.Also bone marrow smears were stained with Giemsa stain todetermine the percentage of transformed lymphocytes in the bonemarrow which were considered as an indicator of the degree oflymphocyte proliferation.The results of the present study revealed the following:1-The dexamethasone reduced the size of lymphoidfollicles andtheir germinal centers to a highly significant degree (P < 0.005)and decreased the percentage of transformed lymphocytes in thebone marrow to a highly significant degree when compared withthe control subgroup of the same age at the different age groups.2- The loratadine did not affect the size of lymphoid follicles or theirgerminal centers, and did not decrease the percentage oftransformed Imphocytes in the bone marrow when compared withthe control subgroup of the same age at the different age groups.3- There was a highly significant difference (P < 0.005) between thedifferent age groups in the control, dexamethasone and loratadinesubgroups due to the effect of aging and not due to theadministered drugs.The present study may provide an evidence that it is better touse loratadine in treatment of chronic allergic diseases because it hasno effect on the immune system. In contrast, dexamethasone causeda highly significant depression to the immune system when used forlong periods at the different age groups.