ACTA ENDOCRINOLOGICA (BUC)

Background. Pineal and adrenocortical cell morphology, dynamics, hormonal analysis and function in response to both natural and synthetic corticoids awaits in depth investigation in mammals. Aim. To investigate the pineal responsiveness to corticoid treatment from combined morphological and hormonal studies in postpubertal male mice. Material and methods. Three groups, each with 14 mice were used as control (C) or treated with the natural corticoid, hydrocortisone (HYC) at a dose of 4 mg/100 g.b.w. and synthetic corticoid, dexamethasone (DEX) at a dose of 4 mg/100 g.b.w. for ten consecutive days. Results. The treatment induced inverse changes in pineal-adrenocortical karyomorphology, cell proliferation (mitotic percentage M%) and hormonal milieu. Whereas both these corticoids caused pineal stimulation as evidenced from significantly increased nuclear diameter (μm) values (C 3.35 ± 0.05, HYC 4.77 ± 0.02, DEX 4.59 ± 0.04, p<0.001) and cell proliferation (M%) (C 1.11 ± 0.09, HYC 1.59 ± 0.07, DEX 1.44 ± 0.05, p<0.01), the changes induced in adrenocortical nuclear diameter in all the zones (p<0.001), cell proliferation (M%) (C 1.38 ± 0.05, HYC 0.53 ± 0.06, DEX 0.70 ± 0.05, p<0.001) and decreased content of adrenal corticosterone (C 0.24 ± 0.03, HYC 0.13 ± 0.01, p<0.001 DEX 0.15 ± 0.02, p<0.01) were those of adrenocortical inhibition. Conclusion. There exists an inverse relationship between the pineal and adrenocortical functions in post pubertal male mice (Mus musculus).