PMID- 4018714
OWN - NLM
STAT- MEDLINE
DCOM- 19850923
LR  - 20181130
IS  - 0367-6102 (Print)
IS  - 0367-6102 (Linking)
VI  - 60
IP  - 3
DP  - 1985 May
TI  - [Studies on mechanisms of prolactin synthesis and secretion using perfusion 
      system of rat pituitary cells].
PG  - 404-14
AB  - The direct effect of TRH, dopamine, and hypothalamic extract on prolactin (PRL) 
      synthesis and release were studied in an in vitro perfusion system using female 
      rat pituitary cells and rat pituitary tumor cells (GH3 cells). The cells were 
      exposed to tritium-leucine containing medium during perfusion, and total amounts 
      of released PRL were measured by radioimmunoassay (IR-PRL), while those of newly 
      synthesized PRL by counting immunoprecipitated radioactivity of tritium-labeled 
      PRL (IP-PRL). IP-PRL began to be released immediately after exposure to 
      tritium-leucine, and gradually increased to a plateau within five hours. After 
      this period, calculated specific activity (SA; IP-PRL/IR-PRL) was unchanged by 
      stimulation of TRH, but when TRH (10(-10)M-10(-8)M) was applied in the phase of 
      increasing SA, decreased SA of released PRL was observed, indicating that TRH 
      released previously stored PRL preferentially. Hypothalamic extract showed PRL 
      releasing effect similar to TRH in point of decreasing SA. Continuous 
      administration of TRH evoked pulsatile IR-PRL release, followed by a decrease to 
      basal level, and had no effect on SA except pulsatile decrease coincident with 
      pulses of IR-PRL. Dopamine inhibited PRL release without change of SA and was 
      presumed to affect both newly synthesized and previously stored PRL. However, 
      brief interruption of dopamine infusion evoked PRL release with a decrease of SA, 
      indicating the release of previously stored PRL. In contrast with the 
      heterogenous PRL responsiveness to TRH stimulation in normal pituitary cells, GH3 
      cells, a clonal strain of rat pituitary tumor cells, released PRL in response to 
      TRH with a constantly increasing rate of SA. Thus the concept of functionally 
      heterogenous subpopulations in normal pituitary mammotrope cells was supported.
FAU - Akikawa, K
AU  - Akikawa K
LA  - jpn
PT  - Journal Article
PL  - Japan
TA  - Hokkaido Igaku Zasshi
JT  - [Hokkaido igaku zasshi] The Hokkaido journal of medical science
JID - 17410290R
RN  - 10028-17-8 (Tritium)
RN  - 9002-62-4 (Prolactin)
RN  - 9002-71-5 (Thyrotropin)
RN  - GMW67QNF9C (Leucine)
RN  - VTD58H1Z2X (Dopamine)
SB  - IM
MH  - Animals
MH  - Cells, Cultured
MH  - Dopamine/pharmacology
MH  - Female
MH  - In Vitro Techniques
MH  - Leucine/metabolism
MH  - Perfusion
MH  - Pituitary Gland/*metabolism
MH  - Prolactin/biosynthesis/*metabolism
MH  - Rats
MH  - Rats, Inbred Strains
MH  - Thyrotropin/pharmacology
MH  - Tritium
EDAT- 1985/05/01 00:00
MHDA- 1985/05/01 00:01
CRDT- 1985/05/01 00:00
PHST- 1985/05/01 00:00 [pubmed]
PHST- 1985/05/01 00:01 [medline]
PHST- 1985/05/01 00:00 [entrez]
PST - ppublish
SO  - Hokkaido Igaku Zasshi. 1985 May;60(3):404-14.