Prolactin suppression during pre and post-implantation periods on rat uterine glucosamine synthase activity.
Administration of bromocriptine (Bc), an ergot derivative having dopamine receptor agonist activity, to rats on day 1-5 of pregnancy prevented implantation of blastocysts and significantly suppressed uterine glucosamine 6-phosphate synthase activity. There was no effect on implantation or the enzyme activity when Bc was injected on day 7 or later of pregnancy. Injection of prolactin following Bc partially restored the enzyme activity and increased number of implantation sites. These results indicate that suppression of prolactin on day 1 to 5 of pregnancy causes failure of implantation. Bc on day 9 or later had no effect possibly due to the availability of placental LH/hCG to support the luteal cells.
Vijayan
E
E
School of Life Sciences, Pondicherry University, India.
Jayashree
J
J
D000818:Animals; D001971:Bromocriptine / Q000494:pharmacology*; D010064:Embryo Implantation / Q000187:drug effects; D047108:Embryonic Development; D005260:Female; D005945:Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing) / Q000096:biosynthesis*; D008098:Litter Size / Q000187:drug effects; D011247:Pregnancy; D011388:Prolactin / Q000037:antagonists & inhibitors / Q000502:physiology*; D051381:Rats; D014599:Uterus / Q000201:enzymology*
D001971:Bromocriptine; D011388:Prolactin; D005945:Glutamine-Fructose-6-Phosphate Transaminase (Isomerizing)