Reference

Neurotransmitter-sensitive adenylate cyclase in the hypothalami of guinea-pig, rat and monkey

Neurotransmitter-sensitive adenylate cyclase in the hypothalami of guinea-pig, rat and monkey. Ahn, Ho Sam; Makman, Maynard H. (Dep. Biochem., Albert Einstein Coll. Med., Bronx, N. Y., USA). Brain Res., 138(1), 125-38 (English) 1977. CODEN: BRREAP. DOCUMENT TYPE: Journal CA Section: 2 (Hormone Pharmacology) Section cross-reference(s): 1 The possible influence on biogenic amines and other agents of the adenylate cyclase [9012-42-4] activity of guinea pig, rat, and monkey hypothalami and of monkey median eminence was evaluated. Adenylate cyclase activity of hypothalamic homogenates from guinea pig, rat, and both Cebus appella and Macaca mulatta (rhesus) monkeys was stimulated by catecholamines, NaF, and GPP(NH)P [34273-04-6]. Similar results were obtained for rhesus monkey median eminence. Stimulation by catecholamines of the rat enzyme was enhanced by prior treatment in vivo with reserpine. Dopamine [51-61-6] and norepinephrine [51-41-2] were in general more potent than epinephrine [51-43-4] and isoproterenol [7683-59-2], and in rhesus monkey dopamine was more potent than norepinephrine. In rat hypothalamus, adenylate cyclase was stimulated by methoxamine [390-28-3], a putative a-adrenergic receptor agonist. In guinea pig, but not in rat or monkey hypothalamus, activity was stimulated by histamine [51-45-6] and serotonin [50-67-9]. Guinea pig and to a lesser extent monkey hypothalamic adenylate cyclases were also stimulated by 2-chloroadenosine [146-77-0], an effect which was blocked by theophylline. Adenylate cyclase of both Cebus and rhesus as well as rat hypothalami was stimulated by the dopamine receptor agonists, apomorphine [58-00-4] and 1-(3,4-dihydroxybenzyl)-4-(2-pyrimidinyl)piperazine [50602-50-1]. Apomorphine was equipotent with dopamine in Cebus monkey system. The stimulation by dopamine of Cebus and rhesus monkey hypothalamic adenylate cyclase activity as well as that of rhesus monkey median eminence was effectively antagonized by fluphenazine and other neuroleptic drugs. Phentolamine and propranolol were much less potent than fluphenazine in inhibiting the dopamine-induced stimulation of rhesus hypothalamic enzyme. In general, the predominant adenylate cyclase of hypothalamic homogenates appear to be dopamine sensitive, but in at least certain species activity sensitive to histamine, serotonin, methoxamine, and 2-chloroadenosine may also be evident.

Effect of adenosine, adenosine analogs and drugs inhibiting adenosine inactivation on lipolysis in rat fat cells

Effect of adenosine, adenosine analogs and drugs inhibiting adenosine inactivation on lipolysis in rat fat cells. Fredholm, Bertil B. (Dep. Pharmacol., Karolinska Inst., Stockholm, Swed.). Acta Physiol. Scand., 102(2), 191-8 (English) 1978. CODEN: APSCAX. ISSN: 0001-6772. DOCUMENT TYPE: Journal CA Section: 1 (Pharmacodynamics) Adenosine (I) [58-61-7] inhibited lipolysis stimulated by low (0.03 mM) concn. of noradrenaline (NA).In this article, certain chemicals are used. One of their cas registry numbers is 58-61-7 Lipolysis stimulated by higher concns. (0.3 and 3 mM) of NA was inhibited to a minor degree or not at all. Theophylline (1 mM)-induced lipolysis was inhibited by I (IC50 ~10 mM). Inhibition of theophylline-induced lipolysis was tested for several analogs of I. Some N6-substituted I analogs and 2-chloroadenosine [146-77-0] were more potent inhibitors. Adenine nucleotides (ATP [56-65-5], ADP [58-64-0], AMP [61-19-8]) were about equipotent with I. Several I analogs, including its breakdown products were considerably less potent or ineffective. None of the analogs tested inhibited the action of I. Dipyridamol [58-32-2], dilazep [35898-87-4], and papaverine [58-74-2], which inhibited the uptake of I into cells, caused only a slight enhancement of the antilipolytic effect of I. Thus, I can inhibit lipolysis due to low, physiol. concns. of noradrenaline and low concns. of theophylline via an action on a receptor structure on the cell surface which exhibits structural specificity. .