𝔖 Bobbio Scriptorium
✦   LIBER   ✦

The role of sodium and calcium lons in osmoregulation inHydra littoralis

✍ Scribed by Koblick, Daniel C. ;Rufus, Charles D.

Publisher
John Wiley and Sons
Year
1976
Tongue
English
Weight
509 KB
Volume
197
Category
Article
ISSN
0022-104X

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

The frequency of column contractions in Hydra littoralis (taken as a measure of the rate of water elimination) is maximal at about 5 Γ— 10^βˆ’4^M Na^+^, and falls off markedly at higher and lower concentrations, even though total medium osmotic pressure is kept constant by replacement with K^+^.

Reduction in Ca^++^ concentration causes a reduction in the frequency of column contractions. This reduction is half‐maximal at about 4.8 Γ— 10^βˆ’4^ M Ca^++^.

The significance of these findings in the light of the osmoregulatory mechanism in Hydra is discussed, and it is suggested that Na^+^ plays a regulatory role in the mechanism of extrusion of water and salts from the cells to the gastrovascular cavity.

πŸ“œ SIMILAR VOLUMES

The role of amino acids in anaerobiosis
The role of amino acids in anaerobiosis and osmoregulation in bivalves
✍ Zurburg, Wouter ;De Zwaan, Albertus πŸ“‚ Article πŸ“… 1981 πŸ› John Wiley and Sons 🌐 English βš– 802 KB

## Abstract The role of free amino acids as solutes for cell volume regulation in marine molluscs under salinity stress is well established. Under hypoosmotic stress the intracellular concentrations of amino acids decrease by extrusion from the cells, followed by deamination and/or excretion. Howev

The role of organic osmolytes in osmoreg
The role of organic osmolytes in osmoregulation: From bacteria to mammals
✍ Kinne, Rolf K. H. πŸ“‚ Article πŸ“… 1993 πŸ› John Wiley and Sons 🌐 English βš– 864 KB

## Abstract Cells of marine species are known to establish osmotic balance with their environment by adjusting the concentrations of organic osmolytes rather than inorganic osmolytes such as sodium, potassium, and chloride. These organic osmolytes fall into three classes: polyhydric alcohols such a

The effect of metabolic inhibition on lo
The effect of metabolic inhibition on lon contents and sodium exchange in human lymphocytes
✍ William Negendank; Calvin Shaller πŸ“‚ Article πŸ“… 1982 πŸ› John Wiley and Sons 🌐 English βš– 1008 KB

## Abstract Lymphocytes depleted of ATP by incubation in iodoacetate (IAA) and nitrogen (N~2~) lost K and gained Na. Isotopic Na exchange showed a fast fraction and a slower exponential fraction, the latter conventionally assumed to reflect surface membrane properties. The gain of cell Na was not a