Histochemically demonstrable increase in the catecholamine content of the carotid body in adult rats treated with methylprednisolone or hydrocortisone

Fine Structure of Rat Carotid Body After 6-Methylprednisolone Treatment

“…In this study, even if methylprednisolone treatment may have caused a slight increase in the number of granular vesicles in the cytoplasm of the glomus cells, this increase was not nearly as marked as that caused by hydrocortisone in the SIF cells of the sympathetic ganglia in newborn rats in vivo or in vitro (Eranko et al, 1972b), in spite of a similar increase in the fluorescence intensity (Korkala et al, 1973). This difference in the formation of granular vesicles is not likely to be caused by difference in the specific glucocorticoid compound used because hydrocortisone and methylprednisolone have similar effects on the catecholamine fluorescence of the glomus cells of adult rats (Korkala et al, 1973) is therefore more likely that other factors are responsible, such as age-dependent differences in the mode of storage of catecholamines.…”

“…Injection of 400 mg/kg of methylprednisolone sypionate, which has been shown to cause a marked increase in the fluorescence intensity of the glomus cells in the carotid body of adult rats (Korkala et al, 1973), was in the present study observed to result in the appearance of unusually large clusters of granular vesicles in the cytoplasm of some but not all glomus cells. There was also a general tendency towards an increased number of granular vesicles in the glomus cells, but the change was not statistically significant.…”

“…This difference in the formation of granular vesicles is not likely to be caused by difference in the specific glucocorticoid compound used because hydrocortisone and methylprednisolone have similar effects on the catecholamine fluorescence of the glomus cells of adult rats (Korkala et al, 1973) is therefore more likely that other factors are responsible, such as age-dependent differences in the mode of storage of catecholamines.…”

“…Perhaps the most conspicuous change due to methylprednisolone in the present study was the increased formation of parallel arrays of rough endoplasmic reticulum. Since granular endoplasmic reticulum has been connected with the diffuse component of the catecholamine fluorescence in the perikaryon of sympathetic nerve cells (Eranko, 1972), it is of interest to point out that glucocorticoid treatment results in the appearance of an intense, even fluorescence in the glomus cells of the adult rats, while fluorescent granules are common in the glomus cells of the controls (Korkala et al, 1973). This suggests that a significant part of the increased storage of catecholamines is located in the endoplasmic reticulum, although it is not demonstrable there with the electron microscopic method employed in the present study.…”

“…In the carotid body, whose glomus (type I) cells closely resemble the SIF cells, glucocorticoids cause an increased fluorescence intensity in the glomus cells both in newborn (Hervonen et al, 1972) and in adult rats (Korkala et al, 1973). However, it is not known whether the glucocorticoid-induced increase in the fluorescence intensity of the glomus cells of the adult rat is associated with an increase in the number of granular vesicles, which are a characteristic feature of these cells (Biscoe, 1971).…”