Inhibition of vasopressin-stimulated flank marking behavior by V1-receptor antagonists.
Flank marking, a form of olfactory communication displayed by hamsters, is dependent upon vasopressin-sensitive neurons in the anterior hypothalamus. In the present study two vasopressin type-1 (V1) receptor antagonists, d(CH2)5Tyr(Me)AVP and dPTyr(Me)AVP were tested for their ability to block flank marking stimulated by the microinjection of arginine vasopressin (AVP) into the anterior hypothalamus. Dose-response curves were established for AVP and flank marking in the presence or absence of different concentrations of each antagonist. DPTyr(Me)AVP was microinjected into the anterior hypothalamus 1 h before the microinjection of AVP while d(CH2)5Tyr(Me)AVP and AVP were prepared together and delivered as a single microinjection. This procedure was necessary because dPTyr(Me)AVP, but not d(CH2)5Tyr(Me)AVP, had agonist activity when initially injected into the anterior hypothalamus in concentrations ranging from 0.90-900 microM. The ED50 values (microM) for dPTyr(Me)AVP and AVP were 17.9 and 0.90, respectively. The initial agonist activity of dPTyr(Me)AVP was always followed by blocker activity. Both V1-receptor antagonists caused a dose-dependent decrease in AVP-stimulated flank marking. Maximal inhibition of AVP-stimulated flank marking was produced with approximately 1.0 mM of either antagonist. Both antagonists blocked AVP-stimulated flank marking behavior for over 12 h following their microinjection.
Ferris
C F
CF
Department of Physiology, University of Massachusetts Medical Center, Worcester 01605.
Singer
E A
EA
Meenan
D M
DM
Albers
H E
HE
D000819:Animal Communication / Q000187:drug effects*; D000818:Animals; D001127:Arginine Vasopressin / Q000031:analogs & derivatives / Q000494:pharmacology; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D008297:Male; D008647:Mesocricetus; D011945:Receptors, Angiotensin / Q000378:metabolism*; D017483:Receptors, Vasopressin; D012543:Scent Glands / Q000502:physiology; D014667:Vasopressins / Q000037:antagonists & inhibitors*
D011945:Receptors, Angiotensin; D017483:Receptors, Vasopressin; D014667:Vasopressins; D001127:Arginine Vasopressin; C028888:argipressin, deaminopenicillamine(1)-O-methyl-Tyr(2)-