Social status controls LH secretion and ovulation in female marmoset monkeys (Callithrix jacchus).
Level 5 - mechanism / opinion, no new human data
Animal research (non-human primate physiological study)
PubMed 3134506 · doi:10.1677/joe.0.1170329
What was done
The study investigated endocrine mechanisms of ovulation suppression in subordinate female marmoset monkeys (Callithrix jacchus). Plasma concentrations of luteinizing hormone (LH), oestrogen, and progesterone were measured in subordinate females (n = 5). Hormonal changes were monitored when subordinate females were removed to solitary housing and subsequently re-introduced to subordinate status in new social groups. Pituitary responsiveness to 200 ng gonadotrophin-releasing hormone (GnRH) was measured in subordinate females (n = 8) versus dominant females in the follicular (n = 6) and luteal (n = 10) phases.
What was found
Subordinate females had basal plasma LH usually below 2 IU/l (maximum 10.7 IU/l), oestrogen below 0.62 nmol/l, and progesterone below 30 nmol/l. Solitary housing reversed infertility, with plasma LH reaching up to 140.0 IU/l and oestrogen up to 7.84 nmol/l before ovulation. Re-introduction to subordinate status caused plasma LH to return to suppressed levels within 4 days with no subsequent ovulation, and shortened luteal phases in three females. Maximal LH response to 200 ng GnRH was 19.1 +/- 6.7 IU/l in subordinate females, compared to 40.0 +/- 13.3 IU/l in follicular-phase dominant females and 126.7 +/- 24.9 IU/l in luteal-phase dominant females.
Why it matters
This study shows that social subordination in female marmosets exerts immediate and reversible neuroendocrine control over LH secretion and ovulation, demonstrating social regulation of hypothalamic-pituitary-ovarian function.
Limits
The study is restricted to a small sample of non-human primates (n = 5 to 10 per comparison). Hypothalamic GnRH secretion was inferred from pituitary responsiveness and peripheral hormone dynamics rather than directly measured.
Cited by
- supports In marmoset social groups, the dominant female suppresses ovulation in subordinate females through pheromonal and physiological signaling.