Effect of RbCl on the circadian rhythm of locomotor activity in the cockroachLeucophaea maderae

Rubidium chloride fuses split circadian activity rhythms in hamsters housed in bright constant light

Chronotypic effects of rubidium (Rb) were examined in hamsters whose circadian activity rhythms had split into two components while they were housed in bright constant light. Seven of 12 hamsters receiving RbCl in drinking water for 10 weeks showed fusing of the components into an intact rhythm compared with none of 7 control hamsters (p = 0.016). Rb may modify coupling between circadian oscillators via reduced photic input to the suprachiasmatic nuclei. Alternative mechanisms include changes in potassium metabolism or endocrine function or behavioral changes that in turn alter circadian function. This normalization of a circadian anomaly by a putative antidepressant suggests that Rb may be valuable in strengthening coupling between oscillators in cases of human chronopathology, including those implicated in the etiology of some affective disorders.

Potassium, rubidium, and 4-aminopyridine effects on the circadian running rhythm in the hamster

The period of the circadian rhythm of wheel-running was shortened when golden hamsters were given supplemental dietary potassium or rubidium for two weeks. Treatment with 4-aminopyridine, a potassium channel blocker, significantly increased circadian period. These period changes (0.17 h for potassium treatment, 0.14 h for rubidium, and 0.07 h for 4-aminopyridine) support previous data indicating that potassium is a component of the mammalian biological clock mechanism.

Effects of tetraethylammoniumchloride (TEA), vanadate, and alkali ions on the lateral leaflet movement rhythm of Desmodium motorium (Houtt.) Merr

The period (approximately 3-5 min) of the ultradian rhythm of the lateral leaflet movement of Desmodium motorium is strongly lengthened (less than or equal to 30-40%) by the K+ channel blocker tetraethylammoniumchloride (20, 30, and 40 mM) and vanadate (0.5 and 1 mM), which is an effective inhibitor of the plasma membrane-bound H+ pump. The alkali ions K+, Na+, Rb+, and Cs+ (10-40 mM) shorten the period only slightly (less than or equal to 10-15%). Li+ (5-30 mM), however, increases the period of the leaflet rhythm drastically (less than or equal to 80%). We concluded that the plasmalemma-H(+)-ATPase-driven K+ transport through K+ channels is an essential component of the ultradian oscillator of Desmodium, as has been proposed for the circadian oscillator.

Effect of rubidium on the course of illness and the circadian rectal temperature in a 66-year-old depressive woman

Rubidium (Rb+) has an antidepressive effect and shortens the circadian period in animals, whereas Li+, another alcalic metal, lengthens it. When we treated a depressive Li+ nonresponder with Rb+, we found an improvement of depression as well as a phase advance of the temperature rhythm in relation to the rest-activity rhythm.