Tolazoline clonidine

The agonists were found to vary considerably in their potency, with peak response in chlordimeform and XAMI treated insects occurring at 1 pg/g vs 100 pg/g for OA (Figure 2). The dose-response curves also show that males treated with chlordimeform, XAMI, lofexidine naphazoline, and synephrine exhibited levels of response to 0.01 mg pheromone that were equal to those of OA-treated (100 pg/g) males, but that clonidine, tolazoline, and tramazoline were much less effective, and that dopamine was without effect on male sensitivity. 

Ethylene chlorohydrin (2-chloroethanol) Cloperastine Defosfamide Metronidazole Oxypendyl Ethylenediamine Clonidine HCI Edetate disodium Indanazoline Lofexidine HCI Naphazoline Oxymetazoline HCI Penicillin G Benzathine Tetrahydrozoline HCI Tolazoline Tolonidine nitrate Xylometazoline HCI Ethylene dibromide... 

Tolazoline can antagonize the effects of intravenous clonidine and prevent the brief hypertensive reaction that it often causes (SEDA-2,192) (SEDA-3,180). 

Tolazoline and the structurally related imidazoline tetrahydrozoline may be H2 receptor agonists since tolazoline-induced acid stimulation in the dog can be blocked by burimamide, metiamide and cimetidine and both imidazolines induce characteristic -agonist effects on isolated guinea pig atria preparations which can be blocked by metiamideJ Clonidine, like the imidazolines, has a-adrenergic agonist activity... 

Solutions of drugs were prepared in 145 mM aqueous NaCl, from which a dose series was prepared. dl-Octopamine, dl-synephrine, dopamine, tolazoline, clonidine, yohimbine, cyproheptadine, gramine, chlorpromazine, promethazine, propranolol, metoclopramide, and 3-isobutyl-l-methylxanthine were obtained from Sigma Chemical Co. naphazoline from Aldrich Chemical Co. chlordimeform and phentolamine from Ciba Geigy mianserin from Research Biochemicals Inc. and lofexidine, XAMI, and tramazoline were gifts from Dr. R. Hollingworth, Purdue Univ. 

Our agonist studies were designed to further document the effect of lower doses of OA on male sensitivity to pheromone (as shown in Figure 1), and to provide a pharmacological profile that could be compared with data from other published studies on OA receptors (12-14). The compounds included 1) the phenylethylamines synephrine and dopamine, 2) the formamidine chlordimeform, and 3) the substituted imidazolines naphazoline (2-[ 1-naphthylmethyl] imidazoline ), lofexidine (2-[ l-(2,6-dichlorophenoxy)ethyl]-2-imidazoline), XAMI (2,3-xylylaminomethyl-2-imidazoline), clonidine (2-(2,6-dichloro-anilino)-2-imidazoline), tolazoline (2-benzyl-2-imidazoline), and tramazoline (2-[5,6,7,8-tetrahydro-1-naphthyl]amino-2-imidazoline) ... 

Due to inhibition of sympathetic outflow by central a2-receptor stimulation and the weak peripheral tolazoline and phentolamine, clonidine, an antihypertensive, will be addressed more fully in the next chapter. 

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