Detail of "16980-89-5"

Reference

Effects of dibutyryl cyclic adenosine 3',5'-monophosphate and theophylline on the bullfrog sympathetic ganglion cells

Effects of dibutyryl cyclic adenosine 3',5'-monophosphate and theophylline on the bullfrog sympathetic ganglion cells. Akasu, T.; Koketsu, K. (Sch. Med., Kurume Univ., Kurume, Japan). Br. J. Pharmacol., 60(3), 331-6 (English) 1977. CODEN: BJPCBM. DOCUMENT TYPE: Journal CA Section: 3 (Biochemical Interactions) In the absence or presence of 2mM theophylline (I) [58-55-9], 1-3mM Na dibutyryl cyclic AMP [16980-89-5] did not hyperpolarize, but tended to depolarize bullfrog sympathetic ganglia that were hyperpolarized by 0.3-1mM adrenaline. I did not augment the slow inhibitory postsynaptic potentials (i.p.s.p.) or adrenaline-induced hyperpolarization. Thus cyclic AMP was not essential for the generation of slow i.p.s.p.

Relaxation of heart muscle by catecholamines and by dibutyryl cyclic adenosine 3',5'-monophosphate

Relaxation of heart muscle by catecholamines and by dibutyryl cyclic adenosine 3',5'-monophosphate. Similarity of .beta.-adrenoceptors mediating contractile and relaxant effects of catecholamines in kitten papillary muscle. Kaumann, Alberto J. (Physiol. Inst., Univ. Duesseldorf, Duesseldorf, Ger.). Naunyn-Schmiedeberg's Arch. Pharmacol., 296(3), 205-15 (English) 1977. CODEN: NSAPCC. DOCUMENT TYPE: Journal CA Section: 2 (Hormone Pharmacology) Section cross-reference(s): 1 In isometrically contracting kitten papillary muscles, dibutyryl cyclic AMP Na salt (I Na salt) [16980-89-5] enhanced peak tension, increased rates of contraction and decreased tension of a phasic but not of a small tonic component of KCl-contractures, and caused aftercontractions. The effects of I on papillary muscle were not influenced by (-)-bupranolol-HCl [39669-04-0], a .beta.-adrenoceptor antagonist. Phasic KCl-contractures in papillary muscles were decreased by (-)- [54750-10-6] and (+)-isoprenaline bitartrate [54750-10-6]. For similar effects, 100-fold higher concns. of (+)-isoprenaline than of (-)-isoprenaline were required. Increases in max. rates of contraction and relaxation, increases in peak tension of isometric contractions, and redn. of phasic KCl-contractures by catecholamines were antagonized competitively to a similar extent by (-)-bupranolol. Mean apparent equil. consts. for the .beta.-adrenoceptor-(-)-bupranolol complex of 0.46-0.70 nM were estd. These consts. were quite similar irresp. of whether (-)-isoprenaline, (+)-isoprenaline, or (-)-noradrenaline bitartrate [51-40-1] were used as agonists. Increases in contractile strength, max. rates of contraction and of relaxation of isometric contractions and decreases in KCl-contractures by (-)-isoprenaline were surmountably blocked by (+)-bupranolol-HCl [53032-96-5]. Mean apparent equil. consts. for the receptor-(+)-bupranolol complex were 4-50 nM. The equil. consts. of (-)- and (+)-bupranolol for the receptors mediating pos. inotropic and relaxant effects of catecholamines were not different from consts. for bupranolol-receptor complexes in cell-free membrane particles of heart ventricle. The same .beta.-adrenoceptor may trigger pos. inotropic, relaxant and adenylyl cyclase [9012-42-4]-activating effects of catecholamines in papillary muscle. The partial agonist (-)-dichloroisoprenaline-HCl (DCI) [20879-19-0] (1 .mu.M) decreased by 79% the phasic KCl-contractures of the papillary muscles. DCI stimulated adenylyl cyclase activity of ventricle membranes to <1/4 of max. stimulation by (-)-isoprenaline.