-Inositol 1,4,5-trisphosphate (IP3) induced Ca 2 + release in digitonin permeabllized rat pancreatic acinar cells is specifically inhibited by decavanadate. The ca 2 + release induced with 0.18 flM IP3 is half maximally inhibited with approximately 5 flM decavanadate. Complete inhibition is achieved with around 20 flM decavanadate. Removal of decavanadate from the permeabilized cells fully restores sensitivity towards IP3, indicating the reversibility of the inhibition. Oligovanadate, which inhibits A TP dependent ca 2 + up1ake into intracellular stores, does not influence IP3 induced ca 2 + release. In order to reveal the mechanism underlying the effects of the different vanadate species, binding of IP3 to the same cellular preparations was investigated. We found that binding of IP3 to a high affinity receptor site (I

Although the peptide hormone relaxin is synthesized by the human corpus luteum in vivo, its potential to serve as a local factor in the regulation of luteal function is not clear. Using an enzyme-linked immunosorbent assay for human relaxin, we detected relaxin in the culture medium of human granulosa-lutein cells as early as after 6 days in culture. Moreover, 1 x 10(5) IU/l human chorionic gonadotropin stimulated relaxin release about fourfold during a 48-h incubation on culture days 6-8 (and 7-9), but not earlier (on days 1, 3 and 4). The stimulatory action of human chorionic gonadotropin on progesterone release was not influenced by relaxin, and relaxin alone was without stimulatory effect. However, human recombinant relaxin (between 0.1 and 12.5 micrograms/l) increased intracellular free Ca2+ basal levels to maximal peak levels exceeding 1000 nmol/l in about 64% of all tested cells (N = 168) with no obvious dependency on the culture day. The relaxin-induced Ca2+ signal was not affected by removal of extracellular Ca2+. As depletion of intracellular Ca2+ stores by ionomycin rendered the cells unresponsive to relaxin or diminished their ability to respond, these results point to an intracellular source of the Ca2+ signal. In summary, our data indicate the presence of a functional relaxin receptor on human granulosa-lutein cells, which is linked to Ca2+ release from intracellular stores.

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Myocarditis as a cause for acute heart insufficiency has to be taken into account in young patients without any history of cardiac abnormalities and preceding infections. Cardioembolic stroke may be a consequence. Decisions in secondary stroke prevention should be made on an individual base with regard to medical guidelines as well as risk factors. Neurorehabilitation of sufficient length and quality can lead to functional recovery, improvement of independence in activities of daily living and quality of life, even if the initial situation seems worse and medical complications accompany the course.