Vascular Pharmacology of Mokuboito (Mu-Fang-Yi-Tang) and Its Constituents on the Smooth Muscle and the Endothelium in Rat Aorta

Pharmacological actions of Mokuboito and its constituents (Sinomenium acutumand sinomenine) on rat aorta were examined. Mokuboito andS. acutumat lower concentrations (0.03–1 mg ml−1) contracted the non-loaded aorta, but at higher concentrations (1–3 mg ml−1), reversed to dilate it. The vasoconstriction was blocked by phentolamine (10 μM). Sinomenine failed to exhibit the vasoconstriction. On the other hand, Mokuboito andS. acutumdilated the NE (5 μM)-induced vasoconstriction: at 3 mg ml−1, by 98.9 ± 2.5% (n= 6,P< 0.01) and 97.0 ± 4.8% (n= 6,P< 0.01). Vasorelaxation induced by Mokuboito andS. acutumwas attenuated by indomethacin, L-NMMA and nicardipine. Propranolol decreased the vasorelaxation induced by Mokuboito, but not byS. acutum. Sinomenine also relaxed the constriction and at 100 μM, by 68.8 ± 5.1% (n= 7,P< 0.01). This vasorelaxation was attenuated by indomethacin, L-NMMA and nicardipine, and also by propranolol. Therefore, these results indicate that Mokuboito and its constituents exert both vasodilating actions mediated by endothelium-dependent mechanisms (PGI2and NO from endothelium) and by endothelium-independent mechanisms (Ca2+influx control on smooth muscle cells). Simultaneously, Mokuboito andS. acutumcause the vasoconstrictions mediated through α-adrenoceptor stimulation, but not sinomenine. Also, Mokuboito and sinomenine possess β-adrenoreceptor stimulating action, but notS. acutum.

MAKING APARTHEID WORK: AFRICAN TRADE UNIONS AND THE 1953 NATIVE LABOUR (SETTLEMENT OF DISPUTES) ACT IN SOUTH AFRICA

Most analyses of apartheid labor policy focus on the regulation of the labor market rather than the industrial workplace. Instead, this article investigates the administration of South Africa's 1953 Native Labour (Settlement of Disputes) Act to examine shop-floor control rather than influx control. The article argues that in response to the threat of African trade unionism, apartheid policymakers in the Department of Labour addressed the problem of low African wages and expanded the use of ‘works committees’. By shifting the debate about capitalism and apartheid away from influx control and migrant labor, and towards industrial legislation and shop-floor conflict, the article places working-class struggle at the center of an analysis of apartheid.