5-Antagonist activity

Antagonistic activity determined as the influence on electrically evoked, cholinergic contractions of guinea pig intestine preparations [30],... 

As mentioned above, TRK-850 had excellent pharmacological properties (potent 8 antagonist activity and antitussive effect by p.o. administration). However, a serious defect in TRK-850 was observed during the ADME study. After p.o. administration of tritiated TRK-850 in a rat, the plasma sample showed only a small parent peak with HPLC [3H]-detection. This indicated that TRK-850 was... 

Table 4. Synthetic Analogues of Oxytocin and Vasopressin Having Antagonist Activities...

The use of SPPS allows synthesis of both native oligopeptides and important synthetic analogues. Many of these fragments or substituted analogues have been found to be equal to, or more potent than, the parent molecule and to exhibit long-acting and antagonistic activities. 

The area of nonsteroidal antiestrogens along with other classes of nonsteroidal antagonists of sex-steroid hormone action has been reviewed to 1986, and these compounds have been grouped by chemical stmcture as a basis of classification rather than any biochemical or biological test system utilized to assess antagonist activity (46). 

The quest for compounds that combined the analgesic properties of morphine, were nonaddictive, and lacked the side effects of nalorphine, led to the development of the dmgs shown in Table 3. These compounds have both agonist and antagonist activities. Nalbuphine (14) (23) and buprenorphine... 

Table 3. Drugs Exhibiting Both Opioid Agonist and Antagonist Activities...

Alkoxy-3- 4-[2-(5-tetrazolyl)phenyl]phenylmethyl -4/f-pyrido[l,2-a]py-rimidin-4-ones 417 exhibited potential angiotensin II receptor antagonistic activities (94BMCL183). 

Inhibition of human multidrug resistance P-glycoprotein 1 was investigated by analogs of a potent. 5-opioid antagonist, including (35, 1 lu5)-3-[(4-hydroxy-2,6-dimethylphenyl)methyl]-11,11 u-dihydro-2//-pyrazino[l, 1-b] isoquinoline-l,4(3//,6//)-dione (OIMIIO). Opioid antagonist activity of... 

As noted previously, triarylethylenes substituted by a basic group, such as clomiphene, exhibit estrogen antagonist activity. Formal cyclization of that molecule to a more steroid-like, rigid conformation enhances potency in this series. 

When dealing with large numbers of investigational compounds to be tested for agonist or antagonist activity, the methods used to determine system-independent measures of activity must be identified from the initial profile of activity (data-driven analysis). 

Interestingly, the antagonist activity of ICI and other antiestrogens has also been recently attributed to the ability of these compounds to induce degradation of the ER protein in estrogen target tissues. It is thought that... 

Delta Dysphoria, psychotomimetic effects (eg, hallucinations), respiratory and vasomotor stimulations caused by drugs with antagonist activity... 

Antipsychotics (conventional agents have nonspecific dopamine receptor antagonsim atypical agents also have serotonin antagonist activity), ecopipam, GBR-12909 and other partial dopamine agonists (may be functional antagonists)... 

Figure 1. Structure of (+)-anatoxin-a and two analogs with agonist and noncompetitive antagonist activity, respectively.

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