Effect of parathyroid hormone on portal pressure in portal hypertensive rats.
Conflicting results have been common in the pharmacological treatments of portal hypertension. In an attempt to seek better management of portal hypertension, we studied the effect of the synthetic parathyroid hormone (PTH) fragment, [bPTH-(1-34)], in portal hypertensive rats (partial portal vein ligation). PTH, 10 U/kg, administered via the jugular vein resulted in a reduction of both mean arterial blood pressure (MAP) and portal pressure (PP) to a similar extent (18.9% and 16.9%, respectively). A higher dose (40 U/kg) of PTH lowered the PP by 27.8% and MAP by 43.2%. Hemodynamic experiments, performed with labelled microspheres, demonstrated that PTH decreased the blood flow of the splanchnic and hepatic portal collateral vascular beds. To determine whether there is a direct vasodilatory effect on the venous vasculature, the effect of PTH on the isolated portal vein was examined. PTH was capable of inhibiting both spontaneous and drug (methacholine 10(-7) mol/l or KCl 40 mmol/l-induced contraction in a dose-dependent manner. Therefore, it can be assumed that some of the effect of PTH on portal pressure is due to a selective effect on the portal vein.
Yang
M C
MC
Department of Medical Research, Taipei Veterans General Hospital, Taiwan, R.O.C.
Pang
P K
PK
Lay
C S
CS
Wu
S L
SL
Jan
K M
KM
Tsai
Y T
YT
Kuo
J S
JS
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D006975:Hypertension, Portal / Q000188:drug therapy* / Q000503:physiopathology; D066298:In Vitro Techniques; D010281:Parathyroid Hormone / Q000494:pharmacology* / Q000627:therapeutic use; D011169:Portal Vein / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains
D010281:Parathyroid Hormone