Interactions of angiotensin IV and oxytocin on behaviour in mice.
BACKGROUND
Angiotensin (Ang) IV enhances learning and memory in rats but there are strain differences in its effects in mice. Oxytocin (OT) also influences learning and memory in rats and mice and, in the light of the proposed effects of Ang IV on oxytocinase, the hypothesis that the effects of Ang IV on cognition in mice involve OT was tested.


METHODS
The effects of Ang IV and OT, alone and combined, were determined in rat isolated uterine smooth muscle and in object recognition and forced swim tests in BKW mice.


RESULTS
Ang potentiated the contractile effects of OT in the uterus. Neither peptide had any effect on object recognition nor locomotor activity. Ang IV had no effect in the forced swim test but abolished the effects of OT.


CONCLUSIONS
Ang IV influences the actions of OT in vitro and in vivo, possibly by inhibition of oxytocinase, but the lack of effect of Ang IV on object recognition in BKW mice is unlikely to be a consequence of a deficiency endogenous OT. Unlike OT, Ang IV alone has no effect on learned helplessness in the forced swim test, an effect often used to predict potential antidepressant efficacy in humans.
Gard
Paul R
PR
School of Pharmacy & Biomolecular Sciences, University of Brighton, Brighton, UK. p.r.gard@brighton.ac.uk
Daw
Pauline
P
Mashhour
Zhila Sayyad
ZS
Tran
Paula
P
D000804:Angiotensin II / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D004338:Drug Combinations; D004347:Drug Interactions; D005260:Female; D006380:Helplessness, Learned; D066298:In Vitro Techniques; D007279:Injections, Subcutaneous; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009043:Motor Activity / Q000187:drug effects; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000502:physiology; D010120:Oxytocics / Q000494:pharmacology*; D010121:Oxytocin / Q000494:pharmacology*; D010364:Pattern Recognition, Visual / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D014599:Uterus / Q000187:drug effects* / Q000502:physiology
D004338:Drug Combinations; D010120:Oxytocics; D000804:Angiotensin II; C012877:angiotensin II, des-Asp(1)-des-Arg(2)-Ile(5)-; D010121:Oxytocin