Irreversible shock in rats after injection of microspheres into the renal artery

Summary After injection of microspheres into both renal arteries of rats, an irreversible shock syndrome develops, resulting in death within 4–12 h. Ligation of both renal pedicles after injection of microspheres prevents the shock. It is presumed that kininogenases released from the kidneys participate in the pathogenesis of the shock syndrome.These studies were supported in part by the Deutsche Forschungsgemeinschaft within the SFB 90, Cardiovasculäres System.     

Lithium exchange in from epithelium: determination of unidirectional flux using the stable isotopes 6Li and 7Li in an ionic analyzer]

The use of the stable isotopes 6 and 7 of lithium, and detection with the ionic analyser, allow the measurement of unidirectional transepithelial Li-fluxes, between "external" and "internal" solutions which both contain 80% Na and 20% Li. Efflux was found to be bigger than influx. An important lag-phase on the curve, reveals the interference of a Li-compartment, with a high capacity, in the epithelium itself.     

The effect of dehydration on the neurohypophyseal blood flow in rats with hereditary diabetes insipidus

Summary Neurohypophyseal blood flow increases in water-deprived rats. This increase is independent of vasopressin release, since it occurs even in rats with hereditary defect of hypothalamic vasopressin synthesis.Acknowledgment. The technical assistance of D. Vilimovská is acknowledged.     

Changes in ecdysone levels in the spiderPisaura mirabilis nymphs (Araneae,Pisauridae)

Summary RIA of ecdysones are made on nymphal extracts ofPisaura mirabilis during the intermoulting cycle. The hormone level is low during exuviation and the greatest part of the intermoulting period but increases notably before and after ecdysis. The main hormonal peak or pre-ecdysial peak is due to -ecdysone, characterized by combined TLC/RIA.Acknowledgment. We wish to thank Dr M. Hirn for his help during the manipulations and J. Britton who has translated the text into English.     

A cannabinoid with cardiovascular activity but no overt behavioral effects

Summary Abnormal-⁸-tetrahydrocannabidiol (ABN-⁸-THC) failed to elicit central nervous system and cardiovascular effects in laboratory animals. Abnormal-cannabidiol (ABN-CBD) was also devoid of overt behavioral effects but produced marked hypotension with only slight bradycardia in anesthesized dogs.Acknowledgment. This work was supported by NIDA (grant No. DA-00574-01 and DA-00490) and Virginia Heart Society (grant No. RR-05697)     

A centrally induced vasodepressor response after intravenous administration of whole venom ofNaja mossambica pallida in cats

Summary Naja mossambica pallida venom administered i.v. (300 /kg) produces an initial brief fall in blood pressure, due to a direct myocardial depressant effect, and a sustained fall due to central depressant effect.This study was supported by University of Nairobi research grants (670–376). We also thank Mr E. Njogu for photographic assistance.     

A tissue-selective prostaglandin E2 analog with potent antifertility effects

Summary N-methanesulfonyl 16-phenoxy--tetranor PGE₂ is a prostaglandin analog which is markedly more tissue selective than PGE₂. This compound is 10–30 times more potent than PGE₂ in animal models which are considered relevant to antifertility effects in humans. In pharmacological tests which are believed to be predictive for side effects in humans, the compound has potency either equal to or less than that of PGE₂.     

Determinant selection is a macrophage dependent immune response gene function

Immune response (Ir) genes are linked to the species histocompatibility complex and define as yet uncharacterised phenotypic products which control the immune response to thymus dependent antigens. Antibody formation and antigen induced T lymphocyte proliferation are two examples of immune phenomena which, in vivo and in vitro, operate under Ir gene influence. To clarify their mechanism of action and cellular location, we have examined the contribution of antigen structure (amino acid sequence and conformation to Ir gene control of antigen recognition by T lymphocytes) as well as to the critical role played by the antigen presenting macrophage in expression of that control. We report that immune response gene control of antigen recognition operates at least in part at the level of the macrophage.