Inhibitory role of periventricular dopaminergic mechanisms in hemorrhage-induced vasopressin secretion in conscious rats.
Acute blood loss (16 ml/kg b. wt.) in conscious rats caused, 5 min later, increases in plasma vasopressin (AVP) concentration accompanied by reductions in arterial pressure and hematocrit. The plasma AVP response was markedly enhanced by intracerebroventricular injection (10 microliters) of a dopamine antagonist, haloperidol (0.15 mumol), which did not affect the responses of arterial pressure and hematocrit significantly. These results suggest that periventricular dopaminergic mechanisms may act to inhibit hemorrhage-induced AVP secretion.
Yamaguchi
K
K
Department of Physiology, Niigata University School of Medicine, Japan.
Hama
H
H
Adachi
C
C
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D004298:Dopamine / Q000502:physiology*; D006220:Haloperidol / Q000494:pharmacology*; D006470:Hemorrhage / Q000097:blood / Q000503:physiopathology*; D007276:Injections, Intraventricular; D008297:Male; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology*; D051381:Rats; D011919:Rats, Inbred Strains; D014667:Vasopressins / Q000097:blood*
D014667:Vasopressins; D006220:Haloperidol; D004298:Dopamine