PMID- 2551641
OWN - NLM
STAT- MEDLINE
DCOM- 19891107
LR  - 20181130
IS  - 0013-7227 (Print)
IS  - 0013-7227 (Linking)
VI  - 125
IP  - 4
DP  - 1989 Oct
TI  - The posterior pituitary regulates prolactin, but not adrenocorticotropin or 
      gonadotropin, secretion in the sheep.
PG  - 2204-11
AB  - The aim of this study was to determine the role of the posterior pituitary gland 
      in the control of PRL, LH, FSH, and ACTH secretion in sheep. Posterior pituitary 
      function was removed in ovariectomized ewes by electrical lesioning of the 
      hypothalamo-neurohypophysial tract immediately posterior to the stalk-median 
      eminence (LESION); controls were subjected to sham surgery (SHAM). LESION caused 
      a 2-fold increase in plasma PRL concentrations on days 1-3 after surgery. 
      Thereafter, concentrations gradually declined until they were similar to those in 
      SHAM ewes. There was no change in plasma concentrations of LH, FSH, or ACTH after 
      LESION. Plasma PRL responses to insulin in SHAM ewes were completely abolished, 
      and the plasma PRL response to chlorpromazine was reduced to almost half by 
      LESION. In contrast, audiovisual stress (barking dog) and serotonin challenge 
      caused an immediate release of PRL in both LESION and SHAM ewes, with the 
      amplitude of the responses indistinguishable between groups. LESION had no effect 
      on the plasma ACTH responses to audiovisual stress, insulin, or serotonin. We 
      conclude that the posterior pituitary gland is involved in the regulation of PRL 
      under some circumstances, but not of LH, FSH, or ACTH secretion in the sheep. 
      Accordingly, changes in PRL release after hypothalamopituitary disconnection in 
      this species may reflect a loss of posterior lobe function rather than the 
      removal of hypothalamic inputs. In addition, the PRL response to insulin is 
      dependent on a functional posterior pituitary gland, whereas responses to 
      audiovisual stress and serotonin appear to rely on inputs to the pituitary gland 
      via the median eminence and the long hypothalamo-hypophysial portal blood 
      vessels.
FAU - Thomas, G B
AU  - Thomas GB
AD  - Medical Research Centre, Prince Henry's Hospital, Melbourne, Australia.
FAU - Cummins, J T
AU  - Cummins JT
FAU - Canny, B J
AU  - Canny BJ
FAU - Rundle, S E
AU  - Rundle SE
FAU - Griffin, N
AU  - Griffin N
FAU - Katsahambas, S
AU  - Katsahambas S
FAU - Clarke, I J
AU  - Clarke IJ
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Endocrinology
JT  - Endocrinology
JID - 0375040
RN  - 0 (Gonadotropins)
RN  - 9002-60-2 (Adrenocorticotropic Hormone)
RN  - 9002-62-4 (Prolactin)
RN  - 9002-67-9 (Luteinizing Hormone)
RN  - 9002-68-0 (Follicle Stimulating Hormone)
SB  - IM
MH  - Adrenocorticotropic Hormone/blood/*metabolism
MH  - Animals
MH  - Behavior, Animal/physiology
MH  - Follicle Stimulating Hormone/blood
MH  - Gonadotropins/*metabolism
MH  - Luteinizing Hormone/blood
MH  - Osmolar Concentration
MH  - Pituitary Gland, Posterior/pathology/*physiology
MH  - Prolactin/blood/*metabolism
MH  - Sheep
MH  - Stimulation, Chemical
MH  - Stress, Physiological/blood
EDAT- 1989/10/01 00:00
MHDA- 1989/10/01 00:01
CRDT- 1989/10/01 00:00
PHST- 1989/10/01 00:00 [pubmed]
PHST- 1989/10/01 00:01 [medline]
PHST- 1989/10/01 00:00 [entrez]
AID - 10.1210/endo-125-4-2204 [doi]
PST - ppublish
SO  - Endocrinology. 1989 Oct;125(4):2204-11. doi: 10.1210/endo-125-4-2204.