. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ,W> --!*% out all gills. Further physiological differentiation was re- vealed when the dorsal and ventral epithelia were peeled apart and the individual layers examined. In the central but not the peripheral regions, Na+ + K+ ATPase activity was higher in the ventral portion of the epithelium. Ac- climation to low salinity (15 %o) for 36 h did not result in any increase in enzyme activity in either the gills or the coxal gland (data not shown); lack of short-term Na+ + K+ ATPase activation in Limiihts gills was also repor
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ,W> --!*% out all gills. Further physiological differentiation was re- vealed when the dorsal and ventral epithelia were peeled apart and the individual layers examined. In the central but not the peripheral regions, Na+ + K+ ATPase activity was higher in the ventral portion of the epithelium. Ac- climation to low salinity (15 %o) for 36 h did not result in any increase in enzyme activity in either the gills or the coxal gland (data not shown); lack of short-term Na+ + K+ ATPase activation in Limiihts gills was also reported by Towle ?/«/. (1982). Carbonic anhydrasc activity The distribution of CA in Limu/us gills followed that of the Na/K ATPase, the pattern in most arthropod ion n Figure 3. Semi-tangenlial section through a presumptive ion transporting cell in the ventral portion of the thick region. Note the elaborate membrane tubule network originating from infoldings of the hasal membrane, the dense population of mitochondria, and the basal nucleus (n). Apical region of the cell is under the cuticle (c), and the basal region is in contact with the hemolymph (h). -4515, scale bar = 1 higher activities than gills 1, 4, and 5. The values for the gills were about 2-3 fold higher than those reported by Towle et al. (1982), while activity in the coxal gland was 30% lower than reported previously for animals accli- mated to comparable salinities. The distribution of the Na4 4- K+ ATPase activity within each individual gill, however, was highly local- ized. The central section of the lamellae contained the majority of the enzyme activity. Na+ + K+ ATPase ac- tivity in the central region (approximately 100 nmol Pi mg p«T' min') was about eightfold greater than that in the peripheral region (Fig. 6). With the exception of gill number five, there was no significant difference in Na+ + K+ ATPase activity within the central region in anterior vs. posterior gills. The relatively high variability
Size: 1860px × 1344px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
