Phorbol esters have a dual action through protein kinase C in regulation of proliferation of FRTL-5 cells

AbstractIn quiescent rat thyroid (FRTL-5) cells, phorbol-12-myristate-13-acetate (PMA) inhibited DNA synthesis induced by a combination of insulin and thyrotropin (TSH) or dibutyryl cyclic AMP (Bt2cAMP). This inhibitory effect of PMA was observed even when PMA was added after addition of these growth factors, and was maximal when PMA was added 2–4 h after the growth factors (late in the G1-phase of the cell cycle). On the other hand, PMA alone induced DNA synthesis and also enhanced that induced by Bt2cAMP or insulin in these quiescent cells. 1-Oleoyl-2-acetylglycerol mimicked these effects of PMA, but 4α-phorbol-12,13-didecanoate had no effect. These data demonstrate that in FRTL-5 cells protein kinase C has a stimulatory effect on the G0 to G1 transition and an inhibitory effect on the G1 to S transition in the cell cycle

District Differences in the Measured Values of Arterial Stiffness in Japan.

Background: In Japan, district differences in the prevalence of cardiovascular disease (CVD) are well-known. This study examined district differences in Japan in measured values of arterial stiffness, an independent risk factor for CVD. Methods and Results: Local residents participating in health checkups conducted in the Wakayama (n=461) and Nagano (n=186) prefectures in 2018 were recruited to the study. Brachial-ankle pulse wave velocity (baPWV) was evaluated as an index of arterial stiffness. After multivariate adjustment, baPWV was significantly higher in the Wakayama than Nagano district in subjects aged ≥70 years (mean [±SE] 1,912±25 vs. 1,763±30 cm/s; P{\textless}0.01), but not in subjects aged {\textless}70 years. Multivariate linear regression analysis demonstrated that the Wakayama/Nagano district difference was significantly (P{\textless}0.01) associated with baPWV. Conclusions: District differences were observed in the measured values of arterial stiffness in Wakayama and Nagano. The Wakayama and Nagano prefectures are representative areas with a relatively high and relatively low prevalence of CVD, respectively, in Japan. Therefore, based on the results of the present study, we propose to conduct a study to examine whether district differences in arterial stiffness underlie district differences in the prevalence of CVD