Effects of nifedipine and Bay-K-8644 on the release of catecholamines from the dog adrenal gland in response to splanchnic nerve stimulation.
1. The effects of nifedipine and Bay-K-8644 on the release of adrenal catecholamines were examined in anaesthetized dogs. 2. Splanchnic nerve stimulation (SNS) at 1 and 3 Hz produced frequency-dependent increases in adrenaline (ADR) and noradrenaline (NA) output determined from adrenal venous blood. 3. Neither nifedipine (10 and 30 micrograms/kg, i.v.) nor Bay-K-8644 (10 and 30 micrograms/kg, i.v.) modified the SNS-induced increases in catecholamine output. Basal catecholamine output tended to be increased and decreased by nifedipine and Bay-K-8644, respectively. 4. Nifedipine produced significant decreases in arterial pressure and renal blood flow rate. Bay-K-8644 produced a significant increase in arterial pressure associated with a decrease in renal blood flow rate. 5. These results suggest that dihydropyridine-sensitive calcium channels do not play a major role in adrenal catecholamine release evoked by SNS.
Takeuchi
A
A
Department of Pharmacology, Tohoku University, Sendai, Japan.
Kimura
T
T
Satoh
S
S
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology*; D000311:Adrenal Glands / Q000187:drug effects* / Q000378:metabolism; D000758:Anesthesia; D000818:Animals; D015220:Calcium Channels / Q000502:physiology; D004095:Dihydropyridines / Q000494:pharmacology; D004285:Dogs; D004558:Electric Stimulation; D004837:Epinephrine / Q000097:blood / Q000378:metabolism*; D005260:Female; D008297:Male; D009543:Nifedipine / Q000494:pharmacology*; D009638:Norepinephrine / Q000097:blood / Q000378:metabolism*; D012680:Sensitivity and Specificity; D013153:Splanchnic Nerves / Q000502:physiology*
D015220:Calcium Channels; D004095:Dihydropyridines; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; C038806:1,4-dihydropyridine; D009543:Nifedipine; D009638:Norepinephrine; D004837:Epinephrine