Sex steroid regulation of chin-marking behavior in male New Zealand rabbits.
Chin-marking behavior (chinning) was evaluated daily in nine intact adult male rabbits. All subjects (Ss) displayed chinning (mean of means +/- SE = 61 +/- 7 marks/10 min) but the frequency of this behavior varied largely across them (range of mean chinning frequency = 19-84 marks/10 min). Chinning frequency showed abrupt variations at intervals of 2-3 days, but periodogram analysis did not reveal the existence of an endogenous rhythm in this behavior. Castration significantly decreased (mean of means +/- SE = 29 +/- 9 marks/10 min; p < 0.01). but did not suppress chinning. Testosterone propionate (TP; 1 mg/day for 16 days) restored chinning in castrated Ss to slightly below precastration levels (mean +/- S.E. V 53 +/- 13 marks/10 min). The daily administration of 1 microgram estradiol benzoate (EB) plus 1 mg dihydrotestosterone propionate (DHTP) stimulated chinning within 2 days (mean increase = 147%; p < 0.005). DHTP (1 mg/day) given alone stimulated chinning only after 11 days of treatment (mean increase = 475%; p < 0.01). At higher doses, both DHTP (10 mg/day) and EB (10 or 50 micrograms/day) stimulated chinning by 450%, 80%, and 100%, respectively, over baseline values. Results indicate that chinning largely depends on testicular steroids. Androgen receptor occupation by T or DHT, which is enhanced by E, optimally activates chinning.
González-Mariscal
G
G
Centro de Investigación en Reproducción Animal, CINVESTAV-Universidad Autónoma de Tlaxcala, Tlax, México.
Melo
A I
AI
Zavala
A
A
Chirino
R
R
Beyer
C
C
D000819:Animal Communication; D000818:Animals; D013196:Dihydrotestosterone / Q000378:metabolism; D004958:Estradiol / Q000502:physiology; D012739:Gonadal Steroid Hormones / Q000502:physiology*; D008297:Male; D009919:Orchiectomy; D011817:Rabbits; D012724:Sex Attractants / Q000502:physiology; D012726:Sexual Behavior, Animal / Q000502:physiology*; D012903:Smell / Q000502:physiology; D012931:Social Environment; D013739:Testosterone / Q000502:physiology
D012739:Gonadal Steroid Hormones; D012724:Sex Attractants; D013196:Dihydrotestosterone; D013739:Testosterone; D004958:Estradiol