Abstract
Segments of rectal gland tubules (RGT) the spiny dogfish (Squalus acanthias) were perfused in vitro to study the cellular mechanism by which NaCl secretion is stimulated. Transepithelial PD (PDte), transepithelial resistance (Rte), the PD across the basolateral membrane (PDbl), the fractional resistance of the lumen membrane (FR1), and the cellular activities for Cl−, Na+, and K+ (a cellx ) were measured. In series 1 the effects of stimulation (S) (dbcAMP 10−4, adenosine 10−4, and forskolin 10−6 mol · l−1) on these parameters were recorded and compared to nonstimulated state (NS). PDte increased from −1.9±0.2 mV to −11.0±0.9 mV (n=51). PDbI depolarized from −86±1 to −74±1.4 mV (n=52). Rte fell from 29±2.8 to 21±2 ωcm2 (n=23), and FR1 fell from 0.96±0.005 to 0.79±0.04 (n=9).a cellK+ was constant (123±13 versus 128±17 mmol · 1−1) (n=6), buta cellCl− -fell significantly from 48±4 to 41±3 mmol · l−1 (n=7).a cellNa+ increased from 11±2.1 to 29.5±6.6 mmol · l−1 (n=4). In series 2 the conductivity properties were examined by rapid K+, and Cl− concentration steps on the basolateral and luminal cell side respectively in NS and S states. In NS-segments reduction of bath K+ led to a hyperpolarization of PDbI with a mean slope of 28±1.3 mV/decade (n=9) (as compared to 19 mV/decade for S-state). Reduction of lumen Cl− led to very little depolarization of the lumen membrane PD in NS-state: 6.5±2.3 mV/decade (n=4) (as compared to 13 mV/decade for S-state). In series 3 the effects of furosemide (7 · 10−5 mol l−1, bath) were examined in NS and S tubules. In NS RGT segments furosemide had no effect on PDbI or PDte;a cellCl− fell slowly after furosemide with an initial rate of 0.33 mmol · l−1 s−1, as compared to 1.5 mmol · l−1 · s−1 for S-state. The increase ina cellCl− after removal of furosemide from NS to S-states was examined in the presence of furosemide. Despite the presence of furosemide stimulation was accompanied by a fall in Rte, FR1, anda cellCl− . From these data we conclude that (a) stimulation by cyclic AMP increases the Cl−-conductance of the apical cell membrane at least by a factor of 10, that (b) in the NS-state the Na+2Cl−K+ carrier can be triggered to work at rates similar to the S state by loweringa cellCl− , and that (c) the increase in apical Cl−-conductance is the primary event in cyclic AMP mediated stimulation of NaCl secretion.
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References
Burger JW, Hess WN (1960) Function of the rectal gland in the spiny dogfish. Science 131:670–671
Burg M, Grantham J, Abramow M, Orloff J (1966) Preparation and study of fragments of single rabbit nephrons. Am J Physiol 210:1293–1298
Candia OA (1980) Use of stimulants and inhibitors for study the mechanisms of Cl transport. In: Anion Proton Transp. Ann NY Acad Sci 7:117–124
Degnan KJ, Karnaky KJ, Zadunaisky JA (1977) Active chloride transport in the in vitro opercular skin of a teleost (Fundulus heteroclitus), a gill-like epithelium rich in chloride cells. J Physiol (London) 251:155–191
Diamond JM (1982) Transcellular cross-talk between epithelial cell membranes. Nature 300:683–685
Epstein FH (1979) The shark rectal gland: A model for the active transport of chloride. The Yale J Biol Med 52:517–523
Epstein J, Stevens A, Spokes K, Silva P, Jr., Silva P, Epstein FH (1981) Effect of stimulation of the rectal gland on ouabain binding: Evidence for a direct action of cyclic amp. Bull Mt Desert Is Biol Lab 21:103–108
Fine LG, Hays RM (1975) Observations on the isolated tubule of the dogfish rectal gland. Bull Mt Desert Is Biol Lab 16:37–38
Forrest JN Jr, Rieck D, Murdaugh A (1980) Evidence for a ribose-specific adenosine receptor (Ra) mediating stimulation in the rectal gland of Squalus acanthias. Bull Mt Desert Is Biol Lab 20:152–155
Forrest JN Jr, Wang F, Beyenbach W (1983) Perfusion of isolated tubules of the shark rectal gland. Electrical characteristics and response to hormones. J Clin Invest 72:1163–1167
Frizzell RA, Field M, Schultz SG (1979) Sodium-coupled chloride transport by epithelial tissues. Am J Physiol 236:F1-F8
Frömter E (1979) Solute transport across epithelia: what can we learn from micropuncture studies on kidney tubules. J Physiol 288:1–31
Greger R (1981) Cation selectivity of the isolated perfused cortical thick ascending limb of Henle's loop of rabbit kidney. Pflügers Arch 390:30–37
Greger R, Schlatter E (1983) Properties of the lumen membrane of the cortical thick ascending limb of Henle's loop of rabbit kidney. Pflügers Arch 396:315–324
Greger R, Schlatter E (1984) Mechanisms of NaCl secretion in the rectal gland of spiny dogfish (Squalus acanthias). I. Experiments in isolated in vitro perfused rectal gland tubules. Pflügers Arch 402:63–75
Greger R, Schlatter E (1984) Mechanisms of NaCl secretion in rectal gland tubules of spiny dogfish (Squalus acanthias). II. Effects of inhibitors. Pflügers Arch 402:364–375
Hebert SC, Friedman PA, Andreoli TE (1984) The effects of antidiuretic hormone on cellular conductive pathways in mouse medullary thick ascending limbs of Henle. I. ADH increases directly the K+ conductance of apical membranes. J Membr Biol 80:201–219 (1984)
Heintze K, Lies M, Kohnen H, Sehring KH (1982) Inhibition of chloride secretion and sodium absorption of rabbit colonic mucosa by ethacrynic acid. In: Case M, Garner A, Turnberg L (eds) Electrolyte and water transport across gastrointestinal epithelia. Raven Press, New York, p 77–84
Petersen K-U, Reuss L (1983) Cyclic AMP-induced chloride permeability in the apical membrane of Necturus gallbladder epithelium. J Gen Physiol 81:705–729
Reuss L, Reinach P, Weinman SA, Grady TP (1983) Intracellular ion activities and Cl− transport mechanisms in bullforg corneal epithelium. Am J Physiol 244:C336-C347
Schlatter E, Greger R (1984) Mechanism of cAMP-stimulation of active NaCl reabsorption in the isolated perfused medullary thick ascending limb of Henle's loop (mTAL) of mouse nephron. Pflügers Arch 400:86
Schultz SG (1982) Homocellular regulatory mechanism in sodium-transporting epithelia: An extension of the Koefoed-Johnsen-Ussing model. Seminars in Nephrol 2:343–347
Shorofsky SR, Field M, Fozzard HA (1982) The cellular mechanism of active chloride secretion invertebrate epithelia: studies in intestine and trachea. Phil Trans R Soc London B 299:597–607
Shuttleworth TJ (1983) Role of calcium in cAMP-mediated effects in the elasmobranch rectal gland. Am J Physiol 245:R894-R900
Shuttleworth TJ, Thompson JL (1980) The mechanism of cyclic AMP stimulation of secretion in the dogfish rectal gland. J Comp Physiol 140:209–216
Shuttleworth TJ, Thompson JL (1979) Ouabain binding in the rectal gland ofSqualus. The effects of cyclic AMP, sodium and furosemide. Bull Desert Is Biol Lab 19:6–8
Shuttleworth TJ, Thompson JL (1984) Stimulation of the rectal gland by an endogenous peptide. Bull Mt Desert Is Biol Lab (in press)
Silva P, Stoff J, Field M, Fine L, Forrest JN, Epstein FH (1977) Mechanism of active chloride secretion by shark rectal gland: role of Na−K-ATPase in chloride transport. Am J Physiol 233:F298-F306
Silva P, Spokes K, Silva Jr P, Epstein, J, Stevens A, Epstein FH (1982) Further studies on ouabain binding in the rectal gland. Bull Mt Desert Is Biol Lab 22:78–80
Smith PL, Welsh MJ, Stoff JS, Frizzell RA (1982) Chloride secretion by canine tracheal epithelium. I. Role of intracellular cAMP levels. J Membrane Biol 70:217–226
Stoff JS, Silva P, Field M, Forrest J, Stevens A, Epstein FH (1977) Cyclic AMP regulation of active chloride transport in the rectal gland of marine elasmobranchs. J Exp Zool 199:443–448
Welsh MJ, Smith PL, Fromm M, Frizzell RA (1982) Crypts are the site of intestinal fluid and electrolyte secretion. Science 218:1219–1221
Welsh MJ, Smith PL, Frizzell RA (1983) Chloride secretion by canine tracheal epithelium. III. Membrane resistances and electromotive forces. J Membr Biol 71:209–218
Zadunaisky JA, Wiederholt M (1983) Interaction of papaverine with db-cAMP on apical membrane of Cl secretory epithelium of the frog cornea. Fed Proc 42 (5):5800
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Supported by Deutsche Forschungsgemeinschaft Gr 480/8-1, and by NIH Grant AM 34208
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Greger, R., Schlatter, E., Wang, F. et al. Mechanism of NaCl secretion in rectal gland tubules of spiny dogfish (Squalus acanthias). Pflugers Arch. 402, 376–384 (1984). https://doi.org/10.1007/BF00583938
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DOI: https://doi.org/10.1007/BF00583938