Primate Sexuality
Next Exam: SPRING is key word to remember for extra credit!!
I. Hormonal Cycle of Females
a. Last lecture: established covariation between periovulatory surge of estradiol (E2) and female sexual
behaviors
b. Caveat: this same peak point there is ALSO a peak in testosterone—could this be the real hormone
behind the increased female sexual behavior
II. Adrenal Androgens in Female Behavior Waxenberg, Drellich & Sutherland (1959)
a. Study subjects: 29 women, 51 years of age (mean0
b. Procedure: simultaneous ovariectomy & adrenalectomy (because of metatastic breast cancer)
c. Results: Reported greater loss in libido following adrenal ectomy than from ovariectomy, most
women lost sexual desire postoperative decrease in intercourse
d. Interpretation: adrenal critical to maintenance of libido
e. Problems?
i. Removal of adrenals does not imply that androgens are whats causing loss in sexual desire,
as androgens are precursors for estrogens
ii. Also, loss in sexual desire could be from the fact that they are dying of breast cancer, having
surgeries… lots of confounding psychological factors and biological
iii. Also no critical control condition (adrenalectomy without ovariectomy
III. Adrenal Suppression Study – Lovejoy & Wallen (1990)
a. Could test if this is true by inhibiting adrenal androgens with dexamethasone (from previous study)
b. Subjects: 8 intact female rhesus in social group, 2 vasectomized males
c. Procedure: studied for 2 menstrual cycles; for 1: Dex administered via SC osmotic minipump, during
other cycle: pumps contained sterile water
d. Design: double-blind cross-over study; one half get Dex first then control condition, other half get
control first and then Dex
i. Every individual undergoes both treatments, so this eliminates individual differences by
every female serving as a control for themselves
ii. Eliminates effects from order of administration
e. Wanted to ensure dex did not disrupt estrogens so that they could isolate effects from the androgens;
no significant difference found
i. All females showed normal hormonal ovulation
f. Would the dex sufficiently suppress adrenals?
i. Rapidly suppressed cortisol (suppressed to 10%), androstenedione, testosterone (suppressed
by 50%)
g. Observed many different behaviors that signal female initiation and a few male initiated behavior
and found no significant difference for ANY of the behaviors—aka they didn’t change when
androgens were removed
h. Conclusion: adrenal androgens have no effect on F behavior or attractivity, thus ovarian hormones
are sufficient to modulate F sexual behavior
i. H/e, ovarian hormones produce androgens in women, the adrenals are not the exclusive
source of androgens
ii. Testosterone can convert either to an estrogen, or can be converted to DHT
iii. Explains why testosterone only suppressed for 50%--androgens still present from the ovaries
i. This study does not eliminate the possibility that ovarian androgens drive female behavior, so need
to modify the study IV. Role of “Ovarian” Androgens in Female Sexual Behavior
a. Subjects: 19 adult ovex F, 8 intact adult M; done in the breeding season so ales have sexual interest
b. Procedures:
i. Females injected daily for 10 days with (treatment groups):
1. vehicle(NoRx): hypothesize no sexual behaviors, - -
2. E(2)B (estradiol benzoate): hypothesis is more sexual behavior, + +
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