A heterologous assay for measuring prolactin in pituitary extracts and plasma from Australian flying foxes (genus Pteropus).
A sensitive heterologous assay was developed to measure prolactin-like activity in Pteropus alecto, P. poliocephalus, and P. scapulatus, Australian flying foxes. Adapted from an established radioimmunoassay for rabbit PRL, it utilises the well-characterised, polyclonal antiserum 33/9 (guinea pig anti-human prolactin). In the assay, pituitary extracts from P. alecto, P. poliocephalus, and P. scapulatus diluted in parallel with ovine prolactin standards, although absolute levels estimated were low. Its usefulness for investigating the role of prolactin in reproduction and seasonality in flying foxes was tested. In a survey of pituitary extracts collected from both sexes of all three species, prolactin was higher in females than in males (P < 0.001). In the few specimens from juveniles, mean prolactin levels in pituitary and plasma were similar to those of adults. Plasma and pituitary samples both contained higher concentrations of prolactin during late pregnancy (P. scapulatus, plasma P < 0.01; pituitary P < 0.01) and lactation (P. poliocephalus, plasma P < 0.005; pituitary P < 0.05) in mature females. Plasma prolactin increased at about the time of parturition, but returned to nonpregnant levels rapidly if lactation was not established. In lactating females, plasma prolactin was suppressed by temporary removal of the sucking young, and was slow to recover after the young was returned to the nipple. Pharmacological responses were tested in pregnant P. poliocephalus: plasma prolactin was low following bromocriptine administration and elevated following domperidone. Prolactin is concluded to play significant roles in the reproductive physiology of female flying foxes and, as in other species, is under dopaminergic regulation.
O'Brien
G M
GM
Department of Physiology and Pharmacology, University of Queensland, Australia.
Curlewis
J D
JD
Martin
L
L
D000818:Animals; D001971:Bromocriptine / Q000494:pharmacology; D002685:Chiroptera / Q000378:metabolism*; D004294:Domperidone / Q000494:pharmacology; D018491:Dopamine Agonists / Q000494:pharmacology; D018492:Dopamine Antagonists / Q000494:pharmacology; D005260:Female; D007774:Lactation / Q000502:physiology; D008297:Male; D010902:Pituitary Gland / Q000737:chemistry*; D011247:Pregnancy; D011388:Prolactin / Q000032:analysis* / Q000097:blood; D011863:Radioimmunoassay / Q000379:methods; D012098:Reproduction / Q000502:physiology; D012621:Seasons; D014020:Tissue Extracts / Q000737:chemistry
D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D014020:Tissue Extracts; D001971:Bromocriptine; D004294:Domperidone; D011388:Prolactin