Maddrell S H, Gardiner B O
J Exp Biol. 1976 Apr;64(2):267-81. doi: 10.1242/jeb.64.2.267.
Nicotine is transported at high rates by Malpighian tubules of larvae of Manduca sexta, Pieris brassicae and Rhodnius prolixus and the transport persists in the absence of alkaloid from the diet. In the fluid-secreting portion of Rhodnius tubules this transport is not coupled to ion transport, nor is it dependent on the physiological state of the animal. The transport, which can occur against a steep electrochemical gradient, shows saturation kinetics with a maximal rate of 700 pmol. min-1 per tubule and is half saturated at 2-3 mM. Nicotine transport independent of ion movements also occurs in the lower resorptive parts of Rhodnius tubules. Both portions of Rhodnius tubules can transport morphine and atropine. These alkaloids and nicotine compete with one naother and are presumed to be carried by the smae transport system. Nicotine transport in Rhodnius was unaffected by organic anions, such as amaranth and benzyl penicillin, or by the organic anion transport inhibitor, probenecid. Fluid secretion in 5-HT-stimulated tubules was reduced by atropine and nicotine, probably by blocking the 5-HT receptors. The Malpighian tubules of adult Calliphora erythrocephala and Musca domestica remove nicotine from bathing solutions, an unknown metabolic accumulating in the tubules. Adult P. brassicae and M. sexta do not exhibit transport of nicotine by their Malpighian tubules.
烟草天蛾、粉纹夜蛾和南美锥蝽幼虫的马氏管能高效转运尼古丁，且在食物中不含生物碱的情况下，这种转运仍会持续。在南美锥蝽马氏管的分泌液部分，这种转运与离子转运不偶联，也不依赖于动物的生理状态。这种能逆陡峭电化学梯度发生的转运呈现出饱和动力学，最大转运速率为每根马氏管700皮摩尔·分钟⁻¹，在2 - 3毫摩尔时达到半饱和状态。在南美锥蝽马氏管较低的重吸收部分也会发生不依赖离子移动的尼古丁转运。南美锥蝽马氏管的这两个部分都能转运吗啡和阿托品。这些生物碱和尼古丁相互竞争，推测是由同一转运系统携带。南美锥蝽中尼古丁的转运不受有机阴离子（如苋菜红和苄青霉素）或有机阴离子转运抑制剂丙磺舒的影响。5 - 羟色胺刺激的马氏管中的液体分泌会被阿托品和尼古丁减少，可能是通过阻断5 - 羟色胺受体实现的。红头丽蝇和家蝇成虫的马氏管能从浸泡液中去除尼古丁，一种未知的代谢产物在马氏管中积累。粉纹夜蛾和烟草天蛾成虫的马氏管不表现出尼古丁转运。
