Fastigial stimulation releases vasopressin in amounts that elevate arterial pressure.
Electrical stimulation of the cerebellar fastigial nucleus (FN) in anesthetized, paralyzed, and artificially ventilated rat with a 10-s stimulus train (50 Hz) resulted in a stimulus-locked elevation in arterial pressure (AP) and heart rate, the fastigial pressor response (FPR). Blockade of autonomic effectors by chemosympathectomy (produced by treatment with 6-hydroxydopamine) combined with adrenalectomy, or by spinal cord transection at C1, abolished the FPR but unmasked an elevation of AP with longer latency (10-12 s) and duration (2-4 min), termed the residual FPR. The residual FPR was 1) abolished by midbrain transection, 2) blocked by administration of a specific antagonist of the vasopressor response to arginine vasopressin (AVP) [1,d(CH2)5Tyr(Me)AVP], and 3) was absent in homozygous and attenuated in heterozygous rats of the Brattleboro strain. FN stimulation elevated AVP threefold (from 13 +/- 1 to 38 +/- 8 pg/ml, P less than 0.02; n = 6) in intact rats and sevenfold in rats with combined chemosympathectomy and adrenalectomy (from 14 +/- 1 to 96 +/- 11 pg/ml, P less than 0.001; n = 9). Stimulation of the cerebellar FN can release AVP. In the absence of sympathoadrenal effectors, the amount so released is enhanced and capable of elevating AP.
D000818:Animals; D001127:Arginine Vasopressin / Q000378:metabolism*; D001794:Blood Pressure; D002529:Cerebellar Nuclei / Q000187:drug effects / Q000502:physiology*; D004553:Electric Conductivity; D004558:Electric Stimulation; D006892:Hydroxydopamines; D008297:Male; D016627:Oxidopamine; D010646:Phentolamine / Q000494:pharmacology; D051381:Rats; D011910:Rats, Brattleboro; D011919:Rats, Inbred Strains; D013045:Species Specificity; D013116:Spinal Cord / Q000502:physiology; D013563:Sympathectomy, Chemical
D006892:Hydroxydopamines; D001127:Arginine Vasopressin; D016627:Oxidopamine; D010646:Phentolamine