Franci C R, Kozlowski G P, McCann S M
Universidade de Sao Paulo, Faculdade de Medicina, Ribeirao Preto, Brazil.
Proc Natl Acad Sci U S A. 1989 Apr;86(8):2952-6. doi: 10.1073/pnas.86.8.2952.
To investigate the influence of various peptides on control of dehydration-induced drinking, water intake elicited by overnight water deprivation was analyzed in groups of male rats after intracerebroventricular (third ventricle, icv) injection of 2 microliters of normal rabbit serum or an equal volume of antiserum directed against angiotensin II (Ab-AII), atrial natriuretic peptide, vasopressin, or oxytocin. There was no difference in water intake after normal rabbit serum and antiserum injections when water was offered immediately after icv injections. Water intake was greatly reduced by Ab-AII when water was offered 1 hr and 3 hr after icv injection. The other antisera were partially effective only when water was offered 3 hr after icv injection. The dipsogenic effect of icv injection of AII in normally hydrated rats was reduced only by icv injection of Ab-AII 3 hr before and not by the other antisera. Ab-AII injected icv had no effect on the drinking that occurred just before and after the onset of darkness and that was associated with eating (prandial drinking). The results indicate that AII is primarily responsible for dehydration-induced drinking, and the other peptides may play a permissive role since their antisera were partially effective, with longer latencies after antiserum injection, which is perhaps the result of gradual diffusion to effective sites within the hypothalamus. In contrast, endogenous AII appears to play little, if any, role in prandial drinking.
为研究各种肽对脱水诱导饮水控制的影响，在雄性大鼠脑室内（第三脑室，icv）注射2微升正常兔血清或等体积针对血管紧张素II（Ab - AII）、心房利钠肽、血管加压素或催产素的抗血清后，分析了过夜禁水引起的水摄入量。icv注射后立即提供水时，正常兔血清和抗血清注射后的水摄入量没有差异。icv注射后1小时和3小时提供水时，Ab - AII可使水摄入量大幅减少。其他抗血清仅在icv注射后3小时提供水时才部分有效。在正常水合的大鼠中，icv注射血管紧张素II的致渴作用仅在icv注射Ab - AII 3小时前才减弱，而其他抗血清则无此作用。icv注射Ab - AII对在黑暗开始前后发生的与进食相关的饮水（餐时饮水）没有影响。结果表明，血管紧张素II是脱水诱导饮水的主要原因，其他肽可能起允许作用，因为它们的抗血清部分有效，抗血清注射后的潜伏期更长，这可能是逐渐扩散到下丘脑内有效部位的结果。相比之下，内源性血管紧张素II在餐时饮水中似乎几乎不起作用。
