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Background: Pain after arthroscopic shoulder surgery is often severe, and establishing a pain treatment regimen that does not delay discharge can be challenging. The reported ability of ketamine to prevent opioid-induced hyperalgesia has not been investigated in this particular setting.

Prolonged physical exercise is associated with several immunological changes, e.g. increase in proinflammatory cytokines, changes in the white blood count etc. Great discrepancies exist with regard to the exercise- induced influence on serum immunoglobulin and neopterin values. One explanation could be the shifts in plasma volume (PV) during and after exercise which might influence plasma concentrations of these parameters. Therefore we investigated the consequences of a marathon race in a homogenous group of experienced runners on plasma volume shifts, serum Immunglobulin and neopterin concentrations. Plasma values with and without correction for plasma volume shifts were compared. PV was significantly diminished after the race (-8.4%) followed by a rise 34h after finish (+8.5%). Serum immunoglobulin IgG, IgA and IgM were increased within the first hours postmarathon and normalized in the recovery period. When chages in PV were considered, only IgA rose significantly. Serum neopterin remained unchanged after the marathon independently whether corrected for PV changes or not. We conclude that the increase in immunoglobulins in our study was mainly the consequence of plasma volume changes. Since neopterin was unchanged we have at least in our study no evidence for exercise-induced activation of the cellular immune system.

Compared with age-matched men, women are resistant to the hypertensive effects of dietary NaCl; however, after menopause, the incidence of salt-sensitive hypertension is similar in women and men. We recently suggested that osmotically inactive [Na.sup.+] storage contributes to the development of salt-sensitive hypertension. The connective tissues, including those immediately below the skin that may serve as a reservoir for osmotically inactive [Na.sup.+] storage, are affected by menopause. We tested the hypothesis that ovariectomy (OVX) might reduce osmotically inactive [Na.sup.+] storage capacity in the body, particularly in the skin. Male, female-fertile, and female OVX Sprague-Dawley (SD) rats were fed a high (8%)- of low (0.1%)-NaCl diet. The groups received the diet for 4 or 8 wk. At the end of the experiment, subgroups received 0.9% saline infusion and urinary [Na.sup.+] and [K.sup.+] excretion was measured. Wet and dry weight (DW), water content in the body and skin, total body [Na.sup.+] (rTB[Na.sup.+]) and skin [Na.sup.+] (rSK[Na.sup.+]) content were measured relative to DW by desiccation and dry ashing. There were no gender differences in osmotically inactive [Na.sup.+] storage in SD rats. All SD rats accumulated [Na.sup.+] if fed 8% NaCl, but rTB[Na.sup.+] was lower in OVX rats than in fertile rats on a low (P < 0.001)- and a high (P < 0.05)-salt diet. OVX decreased rSK[Na.sup.+] (P < 0.01) in the rats. A high-salt diet led to [Na.sup.+] accumulation ([DELTA]SK[Na.sup.+]) in the skin in all SD rats. Osmotically inactive skin [Na.sup.+] accumulation was ~66% of [DELTA]SK[Na.sup.+] in female and 82% in male-fertile rats, but there was no osmotically inactive [Na.sup.+] accumulation in OVX rats fed 8% NaCl. We conclude that skin is an osmotically inactive [Na.sup.+] reservoir that accumulates [Na.sup.+] when dietary NaCl is excessive. OVX leads to an acquired reduction of osmotically inactive [Na.sup.+] storage in SD rats that predisposes the rats to volume excess despite a reduced [Na.sup.+] content relative to body weight. ovariectomy; sodium reservoir; total body sodium; Dahl rats; hypertension

Reduced osmotically inactive Na storage capacity and hypertension in the Dahl model. Am J Physiol Renal Physiol 283: F134-F141, 2002. First published January 29, 2002; 10.1152/ajprenal.00323.2001.--Recent evidence suggested that Na can be stored in an osmotically inactive form. We investigated whether osmotically inactive Na storage is reduced in a rat model of salt-sensitive (SS) hypertension. SS and salt-resistant (SR) Dahl-Rapp rats as well as Sprague-Dawley (SD) rats were fed a high (8%)- or low (0.1%)-NaCl diet for 4 wk (n = 10/group). Mean arterial pressure (MAP) was ,measured at the end of the experiment. Wet and dry weights, water content, total body Na (TBS), and bone Na content were measured by dessication and dry ashing. MAP was higher in both Dahl strains than in SD rats. In SS rats, 8% NaCl led to Na accumulation, water retention, and hypertension due to impaired renal Na excretion. There was no dietary-induced Na retention in SR and SD rats. TBS was variable; nevertheless, TBS was significantly correlated with body water and MAP in all strains. However, the extent of Na-associated volume and MAP increases was strain specific. Osmotically inactive Na in SD rats was threefold higher than in SS and SR rats. Both SS and SR Dahl rat strains displayed reduced osmotically inactive Na storage capacity compared with SD controls. A predisposition to fluid accumulation and high blood pressure results from this alteration. Additional factors, including impaired renal Na excretion, probably contribute to hypertension in SS rats. Our results draw attention to the role of osmotically inactive Na storage. salt sensitive; bone sodium; Dahl rats

Summary: The steady-state concept of Na+ homeostasis, based on short-term investigations of responses to high salt intake, maintains that dietary Na+ is rapidly eliminated into urine, thereby achieving constant total-body Na+ and water content. We introduced the reverse experimental approach by fixing salt intake of men participating in space flight simulations at 12 g, 9 g, and 6 g/day for months and tested for the predicted constancy in urinary excretion and total-body Na+ content. At constant salt intake, daily Na+ excretion exhibited aldosterone-dependent, weekly (circaseptan) rhythms, resulting in periodic Na+ storage. Changes in total-body Na+ (±200–400 mmol) exhibited longer infradian rhythm periods (about monthly and longer period lengths) without parallel changes in body weight and extracellular water and were directly related to urinary aldosterone excretion and inversely to urinary cortisol, suggesting rhythmic hormonal control. Our findings define rhythmic Na+ excretory and retention patterns independent of blood pressure or body water, which occur independent of salt intake. [Copyright &y& Elsevier]

Compared with age-matched men, women are resistant to the hypertensive effects of dietary NaCl; however, after menopause, the incidence of salt-sensitive hypertension is similar in women and men. We recently suggested that osmotically inactive Na[sup +] storage contributes to the development of salt-sensitive hypertension. The connective tissues, including those immediately below the skin that may serve as a reservoir for osmotically inactive Na[sup +] storage, are affected by menopause. We tested the hypothesis that ovariectomy (OVX) might reduce osmotically inactive Na[sup +] storage capacity in the body, particularly in the skin. Male, femalefertile, and female OVX Sprague-Dawley (SD) rats were fed a high (8%)- or low (0.1%)-NaCl diet. The groups received the diet for 4 or 8 wk. At the end of the experiment, subgroups received 0.9% saline infusion and urinary Na[sup +] and K[sup +] excretion was measured. Wet and dry weight (DW), water content in the body and skin, total body Na[sup +] (rTBNa[sup +]) and skin Na[sup +] (rSKNa[sup +]) content were measured relative to DW by desiccation and dry ashing. There were no gender differences in osmotically inactive Na[sup +] storage in SD rats. All SD rats accumulated Na[sup +] if fed 8% NaCl, but rTBNa[sup +] was lower in OVX rats than in fertile rats on a low (P < 0.001)- and a high (P < 0.05)-salt diet. OVX decreased rSKNa[sup +] (P < 0.01) in the rats. A high-salt diet led to Na[sup +] accumulation (ΔSKNa[sup +]) in the skin in all SD rats. Osmotically inactive skin Na[sup +] accumulation was ∼66% of ΔSKNa[sup +] in female and 82% in male-fertile rats, but there was no osmotically inactive Na[sup +] accumulation in OVX rats fed 8% NaCl. We conclude that skin is an osmotically inactive Na[sup +] reservoir that accumulates Na[sup +] when dietary NaCl is excessive. OVX leads to an acquired reduction of osmotically inactive Na[sup +] storage in SD rats that predisposes the rats to volume excess despite a reduced Na[sup +] content relative to body weight. [ABSTRACT FROM AUTHOR]