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J Rybakowski

Publications and source records attributed to J Rybakowski.

At least 55 records · Page 3Linked to original sources
PubMed1978

Erythrocyte concentrations of the lithium ion: clinical correlates and mechanisms of action.

When lithium carbonate is administered to individuals, there is considerable intersubject variation in the extent of accumulation of Li+ by erythrocytes. The primary reason for this is differences in the activity of a Li+-Na+ counterflow system, which, under clinical conditions, removes Li+ from the cell. It appears that some bipolar patients accumulate more Li+ in their red cells than either unipolar depressives or normal controls. The precise clinical characteristics of the bipolar patients who accumulate relatively large amounts of erythrocyte Li+ need to be clarified in future research. Finally, the measurement of red cell concentrations of Li+, in addition to the usual plasma measurement, can be used as an indicator of patient compliance.

Biological Transport, Active↗
PubMed1977

Prediction of the lithium ratio in man by means of an in vitro test.

The movement of the lithium ion (Li+) across the membrane of intact erythrocytes incubated in vitro was assessed under two different experimental conditions in which such transfer occurred primarily due to the activity of a lithium-sodium countertransport system. The 13 subjects on whom the in vitro procedures were done subsequently received lithium carbonate for 14 to 56 days, and the extent of accumulation of Li+ by erythrocytes in vivo was measured. While both in vitro procedures yielded data that correlated with the extent of accumulation of Li+ by erythrocytes in vivo, a system measuring the efflux of Li+ from Li+-loaded cells produced a much higher correlation (0.976). The magnitude of this correlation suggests that this in vitro system can be used for further investigations into the relevance of the erythrocyte accumulation of Li+ to the pathogenesis and treatment of affective disorders.

Adult↗
PubMed1976

Lithium-magnesium relationship in red blood cells during lithium prophylaxis.

The authors investigated lithium and magnesium levels in serum and RBC in 30 patients with affective disorders during lithium prophylaxis. No differences in magnesium levels were found in relation to diagnosis (unipolar, bipolar), sex and age. Mean RBC lithium index was higher in females than in males, particularly in bipolar patients. Magnesium levels in erythrocytes showed a significant negative correlation with RBC lithium and RBC lithium index. Serum magnesium levels did not correlate of lithium concentrations. It was concluded that RBC magnesium may play a role in lithium penetration of RBC and this was discussed in relation to clinical and pathogenetic factors.

Adolescent↗
PubMedDate not supplied

Kinetics of erythrocyte lithium-sodium countertransport in patients with affective illness before and during lithium therapy.

Previous investigations have elucidated an erythrocyte lithium-sodium countertransport (LSC) system as the primary mechanism for extruding lithium from the cell, and this activity has been described in terms of Michaelis-Menten kinetics. In most clinical studies the maximum velocity (Vmax) of the LSC has been measured by estimating the rate of lithium efflux from lithium-loaded cells. To date, few studies have examined whether the affinity (Km) of the LSC for lithium might be altered in patients with affective disorders. In the present study we examined LSC kinetic parameters (Vmax, leak, Km, and in vitro lithium ratio) at baseline in 80 patients with affective disorder and 25 healthy control subjects, and after 6 weeks of lithium administration in 33 of the patients. No differences in Vmax were observed between any patient and control group, although Vmax was significantly lower in unipolar depressed men compared to bipolar men (P = 0.043). The affinity (Km) of the transport 'carrier' for lithium did not differentiate between patient and control groups. Chronic lithium administration caused a decreased Vmax in bipolar men (P = 0.015), an increase in the in vitro lithium ratio in bipolar men (P = 0.002) and bipolar women (P = 0.002), and a marginal increase in Km in bipolar men (P = 0.08) and bipolar women (P = 0.06). Although the present data do not demonstrate an underlying difference for Km between affectively ill patients and controls, they do indicate a decrease in the affinity of the transport 'carrier' for lithium after chronic lithium administration.

Adult↗
PubMedDate not supplied

Erythrocyte cation transport disturbances in patients with endogenous depression.

The active cation transport mechanisms (ouabain-dependent fluxes of sodium; ODS) and potassium (ODK), sodium-potassium adenosine triphosphatase ([Na+-K+]-ATPase) activity as well as lithium-sodium countertransport (LSC) reflecting sodium exchange diffusion, were studied in erythrocytes of forty-four patients with endogenous depression both in acute episode and in remission, and compared with thirty healthy control subjects. During depressive episodes, the activities of all mechanisms studied were significantly lower than those of control subjects. In female depressives the values of ODS and LSC were lower than in males. In remission, the activity of all mechanisms rose, reaching in most patients the values of control subjects. In female patients, activities of ODS and LSC were still lower than in male patients and female controls. The activities of ODS and LSC had the highest discriminating power between depressive patients and control subjects. It appears that membrane pathology may be an aetiologic factor in endogenous depression. A disturbance in erythrocyte transport presents most conspicuously during depressive episodes and in some patients may also persist to the normothymic period.

Adult↗