title: Different receptor mechanisms mediate the effects of endotoxin and interleukin-1 on female sexual behavior.
abstract: Activation of the immune system by lipopolysaccharide (LPS) produces physiological, neuroendocrine and behavioral effects, some of which are mediated by cytokine production. We have previously shown that the cytokine interleukin-1 (IL-1) inhibits sexual behavior in female, but not male rats, while producing a comparable suppression of locomotion in both sexes. The present study examined the effects of LPS on sexual behavior and locomotion of male and female rats, and the involvement of IL-1 receptors in mediating the effects of IL-1 and LPS on females' behavior. Peripheral (i.p.) administration of LPS (50 or 250 microg/kg) significantly decreased sexual behavior in females, up to 6 h after administration, while it had no effect on male sexual behavior. However, locomotor activity, measured in the open-field test, was similarly reduced by LPS in both males and females. Pretreatment with the IL-1 receptor antagonist (IL-1ra) either i.p. (10 mg/kg) or intracerebroventricularly (i.c.v.) (50 microg/rat) did not prevent the inhibition of female sexual behavior and locomotion induced by either i.p. (50 microg/kg) or i.c.v. (200 or 400 ng/rat) administration of LPS, respectively. However, identical doses of IL-1ra significantly reversed the effects of IL-1beta, administered either i.p. (5 microg/kg) or i.c.v. (50 ng/rat), respectively. These results demonstrate that both LPS and IL-1beta produce marked inhibition of sexual behavior in female, but not in male rats. However, IL-1 receptors are not required for the effects of LPS on sexual behavior in female rats.
authors.affiliation: Department of Psychology, The Hebrew University of Jerusalem, Mount Scopus, Israel.
authors.forename: R
authors.initials: R
authors.lastname: Avitsur
authors.forename: Y
authors.initials: Y
authors.lastname: Pollak
authors.forename: R
authors.initials: R
authors.lastname: Yirmiya
mesh_terms: D000818:Animals; D004542:Ejaculation; D004731:Endotoxins / Q000494:pharmacology; D004926:Escherichia coli; D005260:Female; D007375:Interleukin-1 / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology*; D010052:Ovariectomy; D051381:Rats; D011919:Rats, Inbred Strains; D012727:Sex Characteristics; D012726:Sexual Behavior, Animal / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors
chemical_list: D004731:Endotoxins; D007375:Interleukin-1; D008070:Lipopolysaccharides