scholarly journals Water permeability of acinar cell membranes in the isolated perfused rabbit mandibular salivary gland.

1990 ◽  
Vol 431 (1) ◽  
pp. 571-583 ◽  
Author(s):  
M C Steward ◽  
Y Seo ◽  
J M Rawlings ◽  
R M Case
Keyword(s):  
Salivary Gland ◽  
Acinar Cell ◽  
Water Permeability ◽  
Cell Membranes

Water permeability of apical and basolateral cell membranes of rat inner medullary collecting duct

1990 ◽  
Vol 259 (6) ◽  
pp. F986-F999 ◽  
Author(s):  
B. Flamion ◽  
K. R. Spring
Keyword(s):  
Water Flow ◽  
Water Permeability ◽  
Cell Membranes ◽  
Apical Membrane ◽  
Collecting Duct ◽  
Basolateral Membrane ◽  
Volume Regulatory Decrease ◽  
Water Permeation ◽  
Inner Medullary Collecting Duct ◽  
Medullary Collecting Duct

To quantify the pathways for water permeation through the kidney medulla, knowledge of the water permeability (Posmol) of individual cell membranes in inner medullary collecting duct (IMCD) is required. Therefore IMCD segments from the inner two thirds of inner medulla of Sprague-Dawley rats were perfused in vitro using a setup devised for rapid bath and luminal fluid exchanges (half time, t1/2, of 55 and 41 ms). Differential interference contrast microscopy, coupled to video recording, was used to measure volume and approximate surface areas of single cells. Volume and volume-to-surface area ratio of IMCD cells were strongly correlated with their position along the inner medullary axis. Transmembrane water flow (Jv) was measured in response to a variety of osmotic gradients (delta II) presented on either basolateral or luminal side of the cells. The linear relation between Jv and delta II yielded the cell membrane Posmol, which was then corrected for membrane infoldings. Basolateral membrane Posmol was 126 +/- 3 microns/s. Apical membrane Posmol rose from a basal value of 26 +/- 3 microns/s to 99 +/- 5 microns/s in presence of antidiuretic hormone (ADH). Because of amplification of basolateral membrane, the ADH-stimulated apical membrane remained rate-limiting for transcellular osmotic water flow, and the IMCD cell did not swell significantly. Calculated transcellular Posmol, expressed in terms of smooth luminal surface, was 64 microns/s without ADH and 207 microns/s with ADH. IMCD cells in anisosmotic media displayed almost complete volume regulatory decrease but only partial volume regulatory increase.

scholarly journals Pancreatic changes in somatostatin content and receptor/effector system after intrapancreatic injection of 5,7-dihydroxytryptamine

1995 ◽  
Vol 145 (2) ◽  
pp. 227-234 ◽  
Author(s):  
G Muñoz-Acedo ◽  
I Alvaro-Alonso ◽  
E Arilla
Keyword(s):  
Adenylate Cyclase ◽  
Acinar Cell ◽  
Pertussis Toxin ◽  
Exocrine Pancreas ◽  
Cell Membranes ◽  
Nerve Fibers ◽  
Pancreatic Acinar Cell ◽  
Guanine Nucleotide ◽  
Inhibitory Protein ◽  
Effector System

Abstract To date, it is unknown whether intrapancreatic serotonergic nerves can influence pancreatic somatostatin (SS) content and the SS receptor/effector system in the exocrine pancreas. In this study, the intrapancreatic serotonergic nerves were chemically ablated by injecting a specific serotonin (5-HT) neurotoxin, 5,7-dihydroxytryptamine (5,7-DHT), into the substance of the gland. Three days after the injection, the 5-HT-like immunoreactive levels in the pancreas were reduced by more than 85% whereas somatostatin-like immunoreactive levels had increased (86%). The number of SS receptors in the pancreatic acinar cell membranes of the 5,7-DHT-treated rats was also increased (72%). No significant differences were seen in basal or forskolin-stimulated adenylate cyclase (AC) enzyme activities in the control and the 5,7-DHT-treated groups. In spite of the increase in the number of SS receptors in the pancreatic acinar cell membranes of 5,7-DHT-treated rats, SS caused a significantly lower inhibition of AC activity in these membranes. This finding is related to the observed decrease of a 41 kD pertussis toxin-sensitive substrate, presumably the αi subunit of the guanine nucleotide inhibitory protein, in pancreatic acinar cell membranes 3 days after intrapancreatic 5,7-DHT administration when compared with the corresponding controls. The functions of pancreatic serotonergic nerves seem to be associated with enteropancreatic communication. These data together with the present results suggest that pancreatic SS content and the SS receptor/effector system in the exocrine pancreas may be regulated by enteropancreatic serotonergic nerve fibers and may participate in enteropancreatic reflexes. Journal of Endocrinology (1995) 145, 227–234

Comments on: Effect of turgor pressure on water permeability ofAllium cepa epidermis cell membranes

1978 ◽  
Vol 41 (1) ◽  
pp. 87-91 ◽  
Author(s):  
Ernst Steudle ◽  
Ulrich Zimmermann ◽  
J. P. Palta ◽  
E. J. Stadelmann
Keyword(s):  
Water Permeability ◽  
Cell Membranes ◽  
Turgor Pressure ◽  
Ofallium Cepa ◽  
Epidermis Cell

scholarly journals Phorbol Ester or Diacylglycerol Modulates Somatostatin Binding to Its Receptors on Rat Pancreatic Acinar Cell Membranes

1986 ◽  
Vol 62 (7) ◽  
pp. 807-817
Author(s):  
Takashi MATOZAKI ◽  
Choitsu SAKAMOTO ◽  
Munehiko NAGAO ◽  
Shigeaki BABA
Keyword(s):  
Acinar Cell ◽  
Phorbol Ester ◽  
Cell Membranes ◽  
Pancreatic Acinar Cell

scholarly journals Water Permeability of Chlorella Cell Membranes by Nuclear Magnetic Resonance

1978 ◽  
Vol 62 (1) ◽  
pp. 146-151 ◽  
Author(s):  
Darryl G. Stout ◽  
Peter L. Steponkus ◽  
Larry D. Bustard ◽  
Robert M. Cotts
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Water Permeability ◽  
Cell Membranes ◽  
Chlorella Cell ◽  
Nuclear Magnetic
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