title: The influence of amphotericin B and neomycin on the effect of human relaxin-2 on foetal membranes and isolated myometrium.
abstract: In vitro studies have documented effects of relaxin on utero-placental tissues. Previously unpublished experiments indicate that neomycin and amphotericin B in vitro influences the effect of human relaxin-2 on the strength of human foetal membranes. The aim of the current study was to investigate the interaction between neomycin and amphotericin B and human relaxin-2 using human foetal membranes, human myometrium and rat myometrium. Chloramphenicol, erythromycin and penicillin were also examined. Human foetal membranes were stretched until rupture in a materials-testing machine while the contractility of rat and human myometrium were examined by myography. Human relaxin-2 (hrlx-2, 10(-9) M) induced a decreased strength in human foetal membranes, although this effect of hrlx-2 was inhibited after co-incubation with neomycin and amphotericin B. Hrlx-2 (10(-9) M) in combination with chloramphenicol induced a decreased strength of human foetal membranes. Hrlx-2 (10(-9) M) decreased myometrial contractility on amplitude and frequency in the rat myometrium, but had no effect on baseline tension. After exposure to amphotericin B, hrlx-2 induced a more pronounced decrease in amplitude, increased baseline tension and increased the frequency of contractions of the rat myometrium. Hrlx-2 (10(-9) M) had no effect on the human myometrium. However, after exposure to amphotericin B or neomycin+amphotericin B, hrlx-2 induced an increase in baseline tension and a decrease in amplitude. Amphotericin B and neomycin+amphotericin B increased the frequency of contractions and this effect was further enhanced by the addition of hrlx-2. We therefore conclude that amphotericin B and neomycin + amphotericin B may have an influence on relaxin's effect on isolated foetal membranes and myometrium.
authors.affiliation: Department of Obstetrics and Gynaecology Y, Aarhus University Hospital, DK-8200 Aarhus N, Denmark. idavogel@d-adlnet.dk
authors.forename: Ida
authors.initials: I
authors.lastname: Vogel
authors.forename: Henning
authors.initials: H
authors.lastname: Grønbaek
authors.forename: Niels
authors.initials: N
authors.lastname: Uldbjerg
authors.forename: Axel
authors.initials: A
authors.lastname: Forman
mesh_terms: D000666:Amphotericin B / Q000494:pharmacology*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004347:Drug Interactions; D005321:Extraembryonic Membranes / Q000737:chemistry / Q000187:drug effects*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects; D009215:Myometrium / Q000187:drug effects* / Q000502:physiology; D009355:Neomycin / Q000494:pharmacology*; D011247:Pregnancy; D051381:Rats; D017208:Rats, Wistar; D012065:Relaxin / Q000378:metabolism / Q000494:pharmacology*; D013045:Species Specificity; D014590:Uterine Contraction / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; C095068:RLN2 protein, human; D000666:Amphotericin B; D012065:Relaxin; D009355:Neomycin