PMID- 11171601
OWN - NLM
STAT- MEDLINE
DCOM- 20010322
LR  - 20181130
IS  - 0193-1849 (Print)
IS  - 0193-1849 (Linking)
VI  - 280
IP  - 3
DP  - 2001 Mar
TI  - Desensitization of angiotensin II: effect on [Ca2+]i, inositol triphosphate, and 
      prolactin in pituitary cells.
PG  - E462-70
AB  - Activation of pituitary angiotensin (ANG II) type 1 receptors (AT1) mobilizes 
      intracellular Ca2+, resulting in increased prolactin secretion. We first assessed 
      desensitization of AT1 receptors by testing ANG II-induced intracellular Ca2+ 
      concentration ([Ca2+](i)) response in rat anterior pituitary cells. A period as 
      short as 1 min with 10(-7) M ANG II was effective in producing desensitization 
      (remaining response was 66.8 +/- 2.1% of nondesensitized cells). Desensitization 
      was a concentration-related event (EC(50): 1.1 nM). Although partial recovery was 
      obtained 15 min after removal of ANG II, full response could not be achieved even 
      after 4 h (77.6 +/- 2.4%). Experiments with 5 x 10(-7) M ionomycin indicated that 
      intracellular Ca2+ stores of desensitized cells had already recovered when 
      desensitization was still significant. The thyrotropin-releasing hormone 
      (TRH)-induced intracellular Ca2+ peak was attenuated in the ANG II-pretreated 
      group. ANG II pretreatment also desensitized ANG II- and TRH-induced inositol 
      phosphate generation (72.8 +/- 3.5 and 69.6 +/- 6.1%, respectively, for inositol 
      triphosphate) and prolactin secretion (53.4 +/- 2.3 and 65.1 +/- 7.2%), effects 
      independent of PKC activation. We conclude that, in pituitary cells, inositol 
      triphosphate formation, [Ca2+](i) mobilization, and prolactin release in response 
      to ANG II undergo rapid, long-lasting, homologous and heterologous 
      desensitization.
FAU - Gonzalez Iglesias, A
AU  - Gonzalez Iglesias A
AD  - Instituto de Biologia y Medicina Experimental-Consejo Nacional de Investigaciones 
      Cientificas y Tecnicas, 1428 Buenos Aires, Argentina.
FAU - Suarez, C
AU  - Suarez C
FAU - Feierstein, C
AU  - Feierstein C
FAU - Diaz-Torga, G
AU  - Diaz-Torga G
FAU - Becu-Villalobos, D
AU  - Becu-Villalobos D
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Am J Physiol Endocrinol Metab
JT  - American journal of physiology. Endocrinology and metabolism
JID - 100901226
RN  - 0 (Receptor, Angiotensin, Type 1)
RN  - 0 (Receptor, Angiotensin, Type 2)
RN  - 0 (Receptors, Angiotensin)
RN  - 11128-99-7 (Angiotensin II)
RN  - 56092-81-0 (Ionomycin)
RN  - 5Y5F15120W (Thyrotropin-Releasing Hormone)
RN  - 85166-31-0 (Inositol 1,4,5-Trisphosphate)
RN  - 9002-62-4 (Prolactin)
RN  - EC 2.7.11.13 (Protein Kinase C)
RN  - NI40JAQ945 (Tetradecanoylphorbol Acetate)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Angiotensin II/*pharmacology
MH  - Animals
MH  - Calcium/*metabolism
MH  - Cells, Cultured
MH  - Drug Tolerance
MH  - Female
MH  - Inositol 1,4,5-Trisphosphate/*metabolism
MH  - Ionomycin/pharmacology
MH  - Pituitary Gland, Anterior/*drug effects/*metabolism
MH  - Prolactin/*metabolism
MH  - Protein Kinase C/metabolism
MH  - Rats
MH  - Rats, Sprague-Dawley
MH  - Receptor, Angiotensin, Type 1
MH  - Receptor, Angiotensin, Type 2
MH  - Receptors, Angiotensin/drug effects/physiology
MH  - Tetradecanoylphorbol Acetate/pharmacology
MH  - Thyrotropin-Releasing Hormone/pharmacology
EDAT- 2001/02/15 11:00
MHDA- 2001/03/27 10:01
CRDT- 2001/02/15 11:00
PHST- 2001/02/15 11:00 [pubmed]
PHST- 2001/03/27 10:01 [medline]
PHST- 2001/02/15 11:00 [entrez]
AID - 10.1152/ajpendo.2001.280.3.E462 [doi]
PST - ppublish
SO  - Am J Physiol Endocrinol Metab. 2001 Mar;280(3):E462-70. doi: 
      10.1152/ajpendo.2001.280.3.E462.