Mutual antagonism

Luo D, Broad LM, Bird GSJ, Putney JW Jr 2001 Mutual antagonism of calcium entry by capacitative and arachidonic acid-mediated calcium entry pathways. J Biol Chem 276 20186-20189... 

Since a herbal combination has obvious advantages in treatment, the relationships between the herbs used in traditional Chinese medicine (TCM) have been carefully studied and certain types of relationship are identified. They are called the seven relations between herbs, e.g. mutual accentuation, mutual enhancement, mutual counteraction, mutual suppression, mutual antagonism, mutual incompatibility and single effect. Some of these are very useful in treatment, but some are harmful and therefore must be avoided. 

Of the above seven types of relationship, those of mutual accentuation and mutual enhancement are commonly used in treatment mutual counteraction and mutual suppression can also be used, especially to reduce herbs side effects or toxicity. The single herb effect is only used in a limited number of disorders relations of mutual antagonism and mutual incompatibility should be avoided in treatment. 

Langley, J.N., On the physiology of the salivary secretion. Part II. On the mutual antagonism of atropin and pilocarpin, having especial reference to their relations in the sub-maxillary gland of the cat. J. Physiol. 1878, 1, 339-369. 

Chang CC, Huang MC, Lee CY (1973) Mutual antagonism between botulinum toxin and -bungarotoxin. Nature 243 166-7... 

McKay LI, Cidlowski JA. Cross-talk between nuclear factor-kappaB and the steroid hormone receptors mechanisms of mutual antagonism. Mol. Endo. 1998 12 45-56. 

Mutual antagonism between both cations in a cation pair was not observed in many cases. Mutual antagonism is a situation where each cation of a cation pair can antagonize the toxicity produced by the other. For example, in the ammonium—sodium system antagonism was observed with ammonium as the toxic cation while synergism was observed when sodium served as the toxic cation. 

Gastrointestinal distress frequently is caused by doses greater than 500 mg fom times a day, even with enteric-coated tablets. Painful and frequent micturition, albuminuria, hematuria, and rashes may result from doses of 4 to 8 g/day given for longer than 3 to 4 weeks. Once the urine is sterile, a high dose should be reduced. Because systemic methenamine has low toxicity at the typically used doses, renal insufficiency does not constitute a contraindication to the use of methenamine alone, but the acids given concurrently may be detrimental. Methenamine mandelate is contraindicated in renal insufficiency. CrystaUuria from the mandelate moiety can occur. Methenamine combines with sulfamethizole and perhaps other sulfonamides in the urine, which results in mutual antagonism. 

The vasoconstrictor action of shed blood tested by perfusion of the rabbit ear is markedly decreased by heparin and this was known long before the identification of the vasoconstrictor activity as serotonin (5-hydroxytryp-tamine). Heparin inhibits the release of both 5-hydroxytryptamine and a polypeptide from platelets into plasma, and in vitro there is mutual antagonism between heparin and 5-hydroxytryptamine . Heparin effectively antagonizes the effect of serotonin on pulmonary vascular bed and bronchial wall musculature and prevents the symptoms of 5-HT release in pulmonary embolism, in the cardiopulmonary by-pass, in experimental burn injuries and in carcinoid tumour. 

While disparate results such as these may be partly explained by the fact that the mutual antagonism and synergism of LSD and 5-hydroxytryptamine are dose dependent, the results themselves do not permit the drawing of firm conclusions concerning the actual mode of action of either compound. Thus, although there is certainly suggestive evidence that the psychotomimetic actions of LSD depend on its relationship with 5-hydroxytryptamine, the nature of the relationship is far from clear and it is likely to remain so until more is known of the physiological role of 5-hydroxytryptamine. 

A urinary antiseptic, this agent is not effective in the treatment of urinary tract infections caused by proteus. Mutual antagonism may occur if this drug is used concomitantly with sulfonamides. 

The activity of methenamine as a urinary antiseptic is mainly due to the release of formaldehyde at acidic pH. Suffonrimides may form insoluble complexes with formaldehyde, resulting in mutual antagonism. Proteus organisms aUtalinize the urine, preventing the release of formaldehyde. The answer is (F). 

Oestreicher P, Cousins RJ. 1985. Copper and zinc absorption in the rat Mechanism of mutual antagonism. J Nutr 115 159-166. 

Cruz, L.J. Benson, L. Berg, C.P. Mutual antagonism in the metabolism of D-valine and D-leucine and antagonism by their analogs. Arch. Biochem. Biophys. 1969, 135, 341-349. 

Comments. In eclat contrast to the pre-conceived view of mutual antagonism between chemo- and immunotherapy, in the last decade clinically documented proof is being continuously provided for the additive, even synergistic, elficacy of combined, selected and properly synchronized chemo-immunotherapy. These treatment protocols are especially valid, if the immunotherapy modality is not a form of a non-specific immunostimulation, but a tumor-specific vaccine [276, 277]. 

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