Study of Adrenocortical Function in Fever. Effect of high temperature on corticoidogenesis in isolated bovine adrenocortical cells / 日本温泉気候物理医学会雑誌

To study the adrenocortical function in fever, we examined the effect of high temperatures on the corticoidogenesis (CG) in isolated bovine adrenocortical cells. To evoke CG, a stimulus was given using adrenocorticotropic hormone (ACTH, 1pM to 10nM), which stimulates the receptor operated Ca²⁺ channel (ROC) and adenylate cyclase activity; dibutyryl cyclic AMP (db-cAMP, 1mM), which mimics intracellular action of cyclic AMP; and high (30mM) K⁺, which activates the voltage dependent Ca²⁺ channel (VDC). Cells were incubated for 1 hour with each of the above mentioned secretaogues at 37°C, 40°C, and 42°C (only for ACTH). Compared with incubation at 37°C, the log dose response curve of ACTH shifted to the right, the maximal effect decreased to about 60% at 40°C, and CG ceased at 42°C. The use of Ca²⁺ (1.2mM) alone evoked CG via the nonspecific Ca²⁺ channel (NSC) at 37°C, but not at 40°C. 30mM K⁺-induced CG decreased to below 50% at 40°C, but 1mM db-cAMP-induced CG decreased only to 80%. However, the conversion of 25-hydroxycholesterol to corticoid was not affected at 40°C<br>The results of these experiments show that VDC and NSC are not the main factors of CG at 40°C and that the enzyme activity beyond the side chain cleavage of cholesterol is not affected. Since the increases in cyclic AMP production and intracellular Ca²⁺ are essential in various stimulants-induced CGs, it is suggested that adenylate cyclase and ROC play a more important role in CG at 40°C than VDC and NSC.

Adrenocortical Function during Hypothermia. (No.2). Inhibitory effect of low temperature on corticoidogenesis in isolated bovine adrenocortical cells / 日本温泉気候物理医学会雑誌

Effects of low temperature on corticoidogenesis (CG) were studied in isolated bovine adrenocortical cells. In the presence of Ca²⁺, cells were incubated with adrenocorticotropic hormone (ACTH) at 27°C and 37°C for 1 hour. After the incubation, the amount of corticoid was measured fluorometrically. After the incubation at 27°C, as compared with that at 37°C, the CGs induced by 10pM and 1nM ACTH decreased, but the CG induced by 10nM ACTH was not affected. Even in the absence of extracellular Ca²⁺, 10nM ACTH could induce the same degree of CGs at 37°C and 27°C, There was no difference in the amount of conversion of 25-hydroxycholesterol to corticoid between the incubations at 37°C and 27°C. The amount of conversion at 20°C, however, was significantly lower.<br>Our study shows that Ca²⁺ is not an important second messenger for CG at 27°C, and that the enzyme activity beyond side chain cleavage of cholesterol (SCC) does not diminish.<br>Because cyclic AMP and Ca²⁺ are known as second messengers of ACTH, it is suggested that cyclic AMP plays a more important role than Ca²⁺ in CG during hypothermia and that ACTH not only stimulates SCC but also activates enzyme (s) beyond SCC to evoke CG in the case of deep hypothermia.

Adrenocortical Function during Hypothermia. Effect of low temperature on the corticoidogenesis in cultured bovine adrenocortical cells / 日本温泉気候物理医学会雑誌

Effects of hypothermia on corticoidogenesis (CG) were investigated in primary cultured bovine adrenocortical cells. In order to evoke CG, adrenocorticotropic hormone (ACTH), dibutyryl cyclic AMP (db-cAMP), and high K⁺ were used. In the presence of the above mentioned secretagogues, cells were incubated at 37°C, 27°C, and 20°C for 1 hour. Although there was no difference between the ACTH-induced CGs at 37°C and 27°C, CG was significantly lower at 20°C. Both db-cAMP and high K⁺-induced CGs were significantly lower at 27°C, and were not observed at 20°C.<br>These results indicate that CG is not affected by moderate hypothermia, and is not eliminated even by deep hypothermia. It is also suggested that ACTH influences not only adenylate cyclase and Ca²⁺ channels, but also various processes of glucocorticoid production and could evoke CG at 20°C in bovine adrenocortical cells.

DETERMINATION OF VITAMIN C IN ADRENAL GLANDS OF MICE AT DIFFERENT ADRENOCORTICAL FUNCTION BY HPLC / 中国药理学通报

With high-performance liquid chromatography ( HPLC ) we have determined the content of Vit C in adrenal glands of mice at different adrenocortical function. The results indicated that the content of Vit C in mice adrenal glands was increased when the adrenocortical function was enhanced with ACTH and Vit C content was decreased when dexamethason was administered. The resultes also indicated that by HPLC-E C the VitC content in mice adrenal glands could be exactly determined.