PMID- 2539754
OWN - NLM
STAT- MEDLINE
DCOM- 19890512
LR  - 20171213
IS  - 0002-9513 (Print)
IS  - 0002-9513 (Linking)
VI  - 256
IP  - 4 Pt 2
DP  - 1989 Apr
TI  - Beta-receptor-adenylate cyclase coupling in hypoxic neonatal rat ventricular 
      myocytes.
PG  - H1209-17
AB  - This study investigated the influence of hypoxia on alterations in the 
      beta-adrenergic receptor-adenylate cyclase system. Cultured neonatal rat 
      ventricular myocytes were subjected to normoxia (incubator PO2 135-145 mmHg) or 
      hypoxia (incubator PO2 0-14 mmHg) and, in crude membrane preparations, 
      beta-receptor binding properties were measured with [125I]iodocyanopindolol and 
      adenylate cyclase activity by radioimmunoassay. Hypoxia of 30 min in duration 
      caused no alteration in beta-receptor density (Bmax 75 +/- 11 vs. 71 +/- 12 
      fmol/mg protein) but increased adenylate cyclase activity under basal conditions 
      and during stimulation with l-isoproterenol, 5'-guanylimidotriphosphate 
      [Gpp(NH)p] 5 X 10(-5) M, NaF 10(-4) M, and forskolin 10(-4) M. For example, 
      isoproterenol 10(-5) M + guanosine 5'-triphosphate (GTP) 5 X 10(-5) M gave 221 
      +/- 34 vs. 143 +/- 11 pmol.min-1.mg protein-1, P less than 0.05 hypoxia vs. 
      normoxia. After 60 min of hypoxia, adenylate cyclase activity was no longer 
      increased. Hypoxia of 120-150 min duration increased Bmax by 64% (73 +/- 8 to 120 
      +/- 11 fmol/mg protein, P less than 0.05 vs. normoxia) but decreased adenylate 
      cyclase activity during stimulation with isoproterenol, NaF 10(-4) M, and 
      forskolin 10(-4) M. For example, isoproterenol 10(-5) M + GTP 5 X 10(-5) M gave 
      107 +/- 12 vs. 148 +/- 11 pmol.min-1.mg protein-1, P less than 0.05 hypoxia vs. 
      normoxia. Reoxygenation for 15 min following 120-150 min of hypoxia reversed the 
      increased beta-receptor numbers and decreased adenylate cyclase 
      activity.(ABSTRACT TRUNCATED AT 250 WORDS)
FAU - Thandroyen, F T
AU  - Thandroyen FT
AD  - Department of Internal Medicine (Cardiology), University of Texas, Southwestern 
      Medical Center, Dallas 75235.
FAU - Muntz, K
AU  - Muntz K
FAU - Rosenbaum, T
AU  - Rosenbaum T
FAU - Ziman, B
AU  - Ziman B
FAU - Willerson, J T
AU  - Willerson JT
FAU - Buja, L M
AU  - Buja LM
LA  - eng
GR  - HL-17669/HL/NHLBI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Am J Physiol
JT  - The American journal of physiology
JID - 0370511
RN  - 0 (Receptors, Adrenergic, beta)
RN  - EC 4.6.1.1 (Adenylyl Cyclases)
RN  - S88TT14065 (Oxygen)
SB  - IM
MH  - Adenylyl Cyclases/*metabolism
MH  - Animals
MH  - Cells, Cultured
MH  - Coronary Disease/metabolism
MH  - In Vitro Techniques
MH  - Myocardium/*metabolism
MH  - Oxygen/*physiology
MH  - Rats
MH  - Receptors, Adrenergic, beta/*metabolism
MH  - Time Factors
EDAT- 1989/04/01 00:00
MHDA- 1989/04/01 00:01
CRDT- 1989/04/01 00:00
PHST- 1989/04/01 00:00 [pubmed]
PHST- 1989/04/01 00:01 [medline]
PHST- 1989/04/01 00:00 [entrez]
AID - 10.1152/ajpheart.1989.256.4.H1209 [doi]
PST - ppublish
SO  - Am J Physiol. 1989 Apr;256(4 Pt 2):H1209-17. doi: 
      10.1152/ajpheart.1989.256.4.H1209.