This body cavity is the largest compartment containing extracellular fluid, the coelomic fluid (CF).
In sea urchins, an indirect effect through the energetic cost of pH compensation in the extracellular fluid, which was reported in several species (see, e.g., Stumpp et al., 2012a; Catarino et al., 2012; Collard et al., 2013b) but not in others (e.g., Miles et al., 2007), could be one of the involved mechanisms.
Renal secretion of renin activates the renin-angiotensin-aldosterone pathway, leading to hormonal regulation of water and sodium in the extracellular fluid
, and to maintenance of blood pressure via this and vasoconstrictive mechanisms (see fig 1).
* Concentration of the hormone in extracellular fluids (e.g., blood).
Unbound steroid hormones readily diffuse across the cell membrane into extracellular fluids. Unlike cells that produce polypeptide hormones, steroid-producing cells do not have a large capacity for storing their hormones.
Only about 1% of the body's magnesium is found in plasma and other extracellular fluids. Plasma concentration is 1.8-2.5 mEq/L or 1.8-2.4 mg/dl, with about 20% of this bound to proteins.
The opposite occurs when the extracellular fluid becomes alkaline.
In previous studies, proton-pump inhibitors eliminated this pH regulation and resulted in very significant acidification of extracellular fluids with a corresponding reduction in [Sigma]C[O.sub.2] concentrations at a given PC[O.sub.2].
All experimental worms were first kept in maintenance vessels with surface seawater conditions, and monitored until extracellular fluid [Sigma]C[O.sub.2] was reduced to a low value ([less than] 10 mmol [1.sup.-1]; about 2-4 days).
Cystatin C, a potent inhibitor of cysteine proteases, is found mainly in extracellular fluids
such as blood, cerebrospinal fluid, and seminal plasma.
The antioxidants of human extracellular fluids
. Arch Biochem Biophys 1990;280:1-8.
However, the issue of measuring glucose in extracellular fluid
needs to be reviewed to assure that values are equivalent to those in plasma.