Effect of bromocriptine administration on maintenance of late pregnancy in the pig.
Plasma concentrations of prolactin, luteinizing hormone (LH) and progesterone were determined in pregnant gilts (n = 6) administered bromocriptine from 67-72 days of pregnancy. Blood samples were taken daily at 2 h intervals from 60 to 80 days of pregnancy. Bromocriptine treatment reduced prolactin from 9.7 +/- 1.4 before to 1.9 +/- 0.6 ng/ml during the treatment (p less than or equal to 0.05) and then returned to the pre-treatment concentrations (10.5 +/- 2.0) following cessation of bromocriptine. Bromocriptine increased LH from 1.4 +/- 0.2 before treatment to 2.9 +/- 0.5 ng/ml (p less than or equal to 0.01) during administration and maintained elevated (3.0 +/- 0.7) in the post-treatment period (p less than or equal to 0.05). Administration of bromocriptine did not alter progesterone concentration in plasma (7.5 +/- 1.2; 7.2 +/- 1.6 and 6.6 +/- 1.6 ng/ml in pretreatment, treatment and post-treatment periods, respectively). This study shows that decrease of prolactin level by bromocriptine treatment does not cause depletion of progesterone secretion in late pregnant pigs.
Szafrańska
B
B
Department of Animal Physiology, University of Agriculture and Technology, Olsztyn/Poland.
Ziecik
A J
AJ
D000818:Animals; D001971:Bromocriptine / Q000494:pharmacology*; D005260:Female; D007986:Luteinizing Hormone / Q000097:blood; D011247:Pregnancy; D011255:Pregnancy Maintenance / Q000187:drug effects*; D011374:Progesterone / Q000097:blood; D011388:Prolactin / Q000097:blood; D013552:Swine / Q000502:physiology*
D001971:Bromocriptine; D011374:Progesterone; D011388:Prolactin; D007986:Luteinizing Hormone