Solvent Water for Electrolytes in the Muscle Fiber of the Giant Barnacle
نویسنده
چکیده
Seven experiments are described which permit estimation of the "solvent water" or the "osmotically active water" of the dissected fiber from the giant barnacle, Balanus nubilus. Each of the first four experiments includes the measurement of a free ion activity in the myoplasm by means of a Na(+), K(+), or Cl(-) ion-specific microelectrode. The fifth experiment makes use of a membrane potential vs. [K](o) curve. The last two experiments measured fiber water and fiber volume as bath osmolarity was changed. The seven independent estimations of solvent water ranged from 0.64 to 0.72 of fiber water with a mean of 0.68. Since the extracellular space of single fibers was about 7% of fiber water, it was concluded that 25% of analyzable water was not acting as solvent for the osmotically active solutes in the myoplasm.
منابع مشابه
Water and electrolyte content of the myofilament phase in the chemically skinned barnacle fiber
Muscle fibers from the giant barnacle, Balanus nubilus, were placed inside the lumen of a porous glass capillary and equilibrated for 48 h in an electrolyte solution containing 2% Tween. The glass capillary prevented the chemically "skinned" fiber from swelling with a water content beyond 80%. Isotope exchange studies using 22Na, 42K, and 36Cl indicated the existence of an intermediate rate con...
متن کاملExchange of 3HHO in intact isolated muscle fiber of the giant barnacle.
(1) Efflux CUN~S of 3HH0 from intact isolated muscle fiber of the giant barnacle were studied by a continuous washout technique. (2) The accuracy of the washout technique was analyzed by studying the efflu of ‘HHO from two models: a) microsacs of collodion and, b) cylinders of agar gel. In both cases the experimental efflux kinetics follow the predictions of the respective models: surface-limit...
متن کاملEffect of External and Internal pH Changes on K and Cl Conductances in the Muscle Fiber Membrane of a Giant Barnacle
The membrane potential and conductance of the giant muscle fiber of a barnacle (Balanus nubilus Darwin) were analyzed in relation to changes in the external (3.5-10.0) and the internal (4.7-9.6) pH, under various experimental conditions. A sharp increase in membrane conductance, associated with a large increase in conductance to Cl ions, was observed when the external pH was lowered to values b...
متن کاملDifferences in Examined by Procaine, and Na and Ca Spikes As Application of Tetrodotoxin, Manganese Ions
The effects of tetrodotoxin, procaine, and manganese ions were examined on the Ca spike of the barnacle muscle fiber injected with Cabinding agent as well as on the action potential of the ventricular muscle fiber of the frog heart. Although tetrodotoxin and procaine very effectively suppress the "Na spike" of other tissues, no suppressing effects are found on "Ca spike" of the barnacle fiber, ...
متن کاملRelation of Membrane Properties of the Giant Muscle Fiber of a Barnacle to Internal Ionic Composition
Giant muscle fibers 1 to 2 mm in diameter and 4 to 5 cm in length are found in the barnacle Balanus nubilus. The preparation offers an excellent opportunity for studying membrane mechanisms of excitation by controlling the internal ionic composition of the fiber. The internal ionic composition was altered by intracellular injection through a glass pipette longitudinally inserted into the fiber....
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- The Journal of General Physiology
دوره 56 شماره
صفحات -
تاریخ انتشار 1970