The thin limbs of Henle's loop in the rabbit
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The thin limbs of short and long loops of Henle of the rabbit kidney were studied by freeze fracture techniques. According to TEM studies of thin sections four segments are discernible: descending thin limbs of short loops, descending thin limbs of long loops, subdivided into an upper and a lower part, and ascending thin limbs (Kaissling and Kriz 1979). This division is supported by findings obtained with the freeze fracture technique and based on differences in the organization of the junctional complexes as well as on differences in the internal morphology of the cell membranes. The descending thin limbs of short loops have junctional complexes established by several closely arranged junctional strands and numerous desmosomes. The upper parts of the long descending thin limbs have tight junctions consisting of a variable number of strands; their outstanding characteristic after freeze fracture is a high density of intramembrane particles in both luminal and baso-lateral membranes. The tight junctions of the lower part of the long descending thin limbs consist of several anastomosing junctional strands, which are, in contrast, loosely arranged; the cell membranes contain only a sparse population of intramembrane particles. The ascending thin limbs are characterized by shallow tight junctions (frequently consisting of only one single junctional strand). Moreover, the epithelial cells of this segment are heavily interdigitated; thereby the tight junctions are correspondingly lengthened.
In addition, this study presents further evidence that remarkable species differences occur among thin limb epithelia. The junctional complexes of the long descending thin limbs of the rabbit are organized quite differently from those of small rodents (e.g., rat, Psammomys).
The data of this study support the concept that the tight junctions are the main determinant of ionic conductances of the paracellular pathway. However, with reference to recent findings from microperfusion studies, it becomes obvious that a correlation of the junctional morphology with the transepithelial water permeability is lacking, at least for the thin limbs.
Key wordsKidney (rabbit) Loop of Henle Freeze fracture
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- Barrett JM, Majack RA (1977) The ultrastructural organization of the rodent Octodon degus. Anat Rec 187:530–531Google Scholar
- Barrett JM, Kriz W, Kaissling B, de Rouffignac C (1978a) The ultrastructure of the nephrons of the desert rodent (Psammomys obesus) kidney. I. Thin limbs of Henle of short-looped nephrons. Am J Anat 151:487–498Google Scholar
- Barrett JM, Kriz W, Kaissling B, de Rouffignac C (1978b) The ultrastructure of the nephrons of the desert rodent (Psammomys rodent) kidney. II. Thin limbs of Henle of long-looped nephrons. Am J Anat 151:499–514Google Scholar
- DiBona DR, Mills JW (1979) Distribution of Na+-pump sites in transporting epithelia. Fed Proc 38:390–400Google Scholar
- Dieterich HJ, Kriz W, Barret JM (1975) The ultrastructure of the thin loop limbs in the mouse kidney. Anat Embryol 147:1–18Google Scholar
- Humbert F, Pricam C, Perrelet A, Orci L (1975) Freeze-fracture differences between plasma membranes of descending and ascending branches of the rat Henle's thin loop. Lab Invest 33:407–411Google Scholar
- Imai M (1977) Function of the thin ascending limb of Henle of rats and hamsters perfused in vitro. Am J Physiol 3:201–209Google Scholar
- Imai M, Kokko JP (1974) Sodium chloride, urea and water transport in the thin ascending limb of Henle: Generation of osmotic gradients by passive diffusion of solutes. J Clin Invest 53:393–402Google Scholar
- Imai M, Kokko JP (1976) Mechanism of sodium and chloride transport in the thin ascending limb of Henle. J Clin Invest 58:1054–1060Google Scholar
- Jamison RL, Robertson CR (in press) Recent formulations of the urinary concentrating mechanism: A status report. Kid IntGoogle Scholar
- Kaissling B, Kriz W (1979) Structural analysis of the rabbit kidney. Advances in Anatomy, Embryology and Cell Biology 55/6Google Scholar
- Kokko JP (1970) Sodium chloride and water transport in the descending limb of Henle. J Clin Invest 49:1838–1846Google Scholar
- Kokko JP (1972) Urea transport in the proximal tubule and the descending limb of Henle. J Clin Invest 51:1999–2008Google Scholar
- Kriz W, Schnermann J, Dieterich HJ (1972) Differences in the morphology of descending limbs of short and long loops of Henle in the rat kidney. Int Symp on Renal Handling of Sodium, Brestenberg 1971. Karger, Basel, 140–144Google Scholar
- Kriz W, Kaissling B, Psczolla M (1978) Morphological characterization of the cells in Henle's loop and the distal tubule. In: Vogel HG, Ullrich KJ (eds) New aspects of renal function. (Workshop Conferences Hoechst) Exerpta Medica, Amsterdam Oxford; 6, 67–78Google Scholar
- Kriz W, Schiller A, Kaissling B, Taugner R (1978) Comparative and functional aspects of thin loop limb ultrastructure. Abst Internat Symposium: Correlation of renal ultrastructure and function. University of Aarhus, AarhusGoogle Scholar
- Majack RA, Paul WK, Barrett JM (1979) The ultrastructural localization of membrane ATPase in rat thin limbs of the loop of Henle. Histochemistry 62:23–33Google Scholar
- Marsh DJ (1970) Solute and water flows in thin limbs of Henle's loop in the hamster kidney. Am J Physiol 218:824–831Google Scholar
- Pricam C, Humbert F, Perrelet A, Orci L (1974) A freeze-etch study of the tight junctions of the rat kidney tubules. Lab Invest 30:286–291Google Scholar
- Schwartz MM, Venkatachalam MA (1974) Structural differences in thin limbs of Henle: Physiological implications. Kid Int 6:103–208Google Scholar
- Schwartz MM, Karnovsky MJ, Venkatachalam M (1976) Ultrastructure differences between rat inner medullary descending and ascending vasa recta. Lab Invest 35:161–170Google Scholar
- Schwartz MM, Karnovsky MJ, Venkatachalam MA (1978) Anatomic segmentation in the thin limbs of Henle's loop in the rat. Abstr Int Symp “The vascular and tubular organization of the kidney”, 10–12, Harvard Med School, BostonGoogle Scholar
- Stoner LC, Roch-Ramel F (1979) The effects of pressure on the water permeability of the descending limb of Henle's loops of rabbits. Pfl ügers Arch 382:7–15Google Scholar