. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. HYPOPHYSECTOMY AND RENAL FUNCTIONS 437 which followed such a transfer. In this experiment the routine followed was 9 hours in 40% sea water, 18 hours in fresh water, and then a transfer into 100% sea water. As shown in Figure 8, 18 hours in fresh water was sufficient time for the osmotic pressure of the serum to fall to levels identical to that of controls that had been held in fresh water continuously. Figure 8 also shows that the short exposure to dilute sea water markedly changed the response to the challenge pre- sented
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. HYPOPHYSECTOMY AND RENAL FUNCTIONS 437 which followed such a transfer. In this experiment the routine followed was 9 hours in 40% sea water, 18 hours in fresh water, and then a transfer into 100% sea water. As shown in Figure 8, 18 hours in fresh water was sufficient time for the osmotic pressure of the serum to fall to levels identical to that of controls that had been held in fresh water continuously. Figure 8 also shows that the short exposure to dilute sea water markedly changed the response to the challenge pre- sented by full-strength sea water. As shown in Figure 9, hypophysectomy alters the response seen when pre- adapted animals are transferred from one environment to the other. In this 600 1/5 LJ 500 to to LJ at a. g 400 to o 300 CONTROLS. 10 20 30 HOURS IN SEAWATER 50 FIGURE 8. The effect of a 9-hour exposure to 40% sea water on the ability of F. kansae to adjust to a transfer from fresh water to sea water. Each point shows the mean ± for 7 animals. experiment, a large number of fish (160) were held in sea water for several weeks. After this adjustment period, half the animals were hypophysectomized and re- turned to sea water. Five days later all the fish were transferred to fresh water for 48 hours, sufficient time for the osmotic pressure of the serum of the hypophy- sectomized fish to fall below that of their controls. The fish were then transferred back into sea water and the osmotic pressure of the serum followed for 23 hours. Then the remaining fish were returned to fresh water. Figure 9 shows that the serum osmotic pressure of the hypophysectomized fish rose above that of their con- trols after the first transfer, and, for that matter, appeared to be rising slowly. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the origin
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
