Phytochrome Control of Maize Leaf Inorganic Pyrophosphatase and Adenylate Kinase

Brief exposure of etiolated maize seedlings to light induces large increases in adenylate kinase and inorganic pyrophosphatase activity of the leaf in the following 48 hr in the dark. Red light is more effective than white or far red light, and far red reverses the effect of red light, indicating phytochrome control. Out of several tested, only these 2 enzymes appear to be coordinately induced, which is consistant with their close functional relationship. For inorganic pyrophosphatase, light treatment induces biosynthesis of a distinctive form of the enzyme characteristic of chloroplasts, readily separable from the enzyme characteristic of etiolated tissue.     

Influence of amphetamines on plasma corticosteroid and growth hormone levels in man

Plasma fluorogenic corticosteroid and immunoreactive growth hormone levels rose significantly after the intravenous administration of methylamphetamine to healthy young men at various times of the day. The rise in corticosteroids was most pronounced in the evening and was accompanied by an increase in circulating levels of immunoreactive corticotrophin. Oral dexamphetamine also resulted in significant rises in plasma corticosteroids but not in growth hormone. These hormonal changes were accompanied by evidence of mild central stimulation. Though they may be part of an associated and non-specific response, it is more likely that they represent specific effects of amphetamines on centres in the hypothalamus or midbrain controlling secretion of corticotrophin and growth hormone releasing factors.