Dose-response effects

Murray, T.F. and Horita, A. Phencyclidine-induced stereotyped behavior in rats Dose response effects and antagonism by neuroleptics. I ife Sci 24 2217-2226, 1979. 

In yet another interesting protocol, Passman and colleagues74 focused on dose-response effects. Nine well-trained cyclists received either 0, 5, 9, or 13 mg/kg caffeine 1 h prior to cycling to exhaustion. All subjects were habituated to caffeine (minimum use 100 mg/d). Significant increases in both endurance and FFA production were associated with caffeine but no significant dose-response effects were noted. 

Breinholt, V., S. T. Lauridsen, B. Daneshvar, and J. Jakobsen. 2000. Dose-response effects of lycopene on selected drug-metabolizing and antioxidant enzymes in the rat. Cancer Lett 154(2) 201-210. 

Radulovacki, M., Virus, R. M., Rapoza, D. Crane, R. A. (1985). A comparison of the dose response effects of pyrimidine ribonucleosides and adenosine on sleep in rats. Psychopharmacology 87 (2), 136-40. 

Yanik, G., Glaum, S. 8r Radulovacki, M. (1987). The dose-response effects of caffeine on sleep in rats. Brain Res. 403 (1), 177-80. 

Figure 7.3 Dose-response effects of MDMA on the release of preloaded [3H]5-HT (left panel) and [3H]DA (right panel) from synaptosomes in vitro. [3H]Transmitter release is expressed as percent of tritium retained in tissue. Various concentrations of MDMA were incubated with or without the 5-HT uptake blocker fluoxetine (10 n/W) in [3H]5-HT assays, whereas various concentrations of MDMA were incubated with or without the DA uptake blocker GBR12909 (10 n/W) in [3H]DA assays. Data are mean SD for three separate experiments, each performed in triplicate. See Baumann et al.39 for methods.

Figure 7.4 Dose-response effects of MDMA on extracellular levels of endogenous 5-HT (left panel) and DA (right panel) in rat nucleus accumbens. Male rats undergoing in vivo microdialysis received i.v. injections of 1 and 3 mg/kg MDMA at 0 and 60 min, respectively. Dialysate levels of 5-HT and DA were assayed by HPLC-ECD. Data are mean SEM, expressed as pg/5 pi sample, for N = 6 rats/group. Baseline levels of 5-HT and DA were 0.22 0.03 and 1.44 0.24 pg/5 pi, respectively. Significant with respect to pre-injection control (P < 0.05 Duncan s). See Baumann et al.39 for methods.

Figure 7.5 Dose-response effects of MDMA on ambulation (left panel) and stereotypy (right panel) in rats...

Fig. 11.4 Dose-response effect of HU on ET-1 peptide release (a) from TrHBM EC cells incubated with various concentrations of HU during 48 h in the presence (A) and absence ( ) of cytokines (TNFaand IFNy at 100 U mL 1). Under the same conditions, quantitative mRNA analysis was also performed and the residual percentage of expression, in the presence (b) and absence (c) of pro-inflammatory cytokines is given.

Wang J, Schramm D and Holt R. 2000. A dose-response effect from chocolate consumption on plasma epicatechin and oxidative damage. J Nutr 130 2115S-2119S. 

Aniline transformed the Balb/3T3 mouse cell line at doses of 0.8 to 100 /Syrian hamster embryo cells (Dunkel et al. 1981). Results were negative in DNA damage assays in Escherichia coli (Mamber et al. 1983) and Bacillus subtilis (McCarroll et al. 1981). 

Using tactile startle, bufotenin, a hallucinogen that does not cross the blood-brain barrier readily, also produced biphasic dose-response effects when given intraventricularly (76). After systemic administration, however, low doses of indole hallucinogens have not been reported to increase tactile startle (73). Thus LSD (20-80 Mg/kg), DMT (0.25-1.0 mg/kg), and psilocin (2.5-5.0 mg/kg) did not increase tactile startle. A slightly higher dose of LSD (100 Mg/kg) did increase startle toward the end of the test session, perhaps because of blocking habituation (see below). 

Davis, M., and Sheard, M. H. (1974) Biphasic dose-response effects of N-N-dimethyltryptamine on the rat startle reflex. Pharmacol. Biochem. Behav., 2 827-829. 

A plethora of effects have been reported from multiple animal studies following exposure to PCDDs, PCDFs and PCBs. The most extensive data set on dose-response effects is available for 2,3,7,8-TCDD less information is available for the other dioxinlike compounds. Therefore, the focus of the evaluation of the animal data is on the effects of 2,3,7,8-TCDD. 

PD is the study to determine dose-response effects. We are interested in finding out the effects of a drug on some particular response, such as heart rate, enzyme levels, antibody production, or muscle relaxation or contraction. When a drug binds to a receptor, the ensuing response is complex. The... 

Epstein JH Nitrogen mustard (mechlorethamine) and UVB photocarcinogenesis a dose response effect. J Invest Dermatol 83 320-322, 1984... 

The effecf of fhe source of Ca on fhe magnifude of Ca-Fe interactions in vivo was assessed in rodents (Smith, 1988), using a whole body radioisotopic retention test as an endpoint to determine true iron bioavailability (i.e., Fe that is absorbed and utilized). A single 50 gg liquid dose of Fe-labeled FeCla was administered by oral gavage to rats at a Ca Fe ratio of 60 1 and 120 1 fo replicate a human iron intake of 15 mg/day and a Ca intake of 800 mg/day or 1600 mg/day, respectively. Ca sources included CaCOa, Ca Phosphate (CaP), bone meal, and Ca hydroxyapatite (CaHA), while the control dose contained no Ca and was normalized to represent 100% Fe retention for comparison purposes. Isotope counts were performed immediafely after dosing (to measure 100% retention) and subsequent counts over 6 days were divided by the 100% count to estimate Fe retention. For CaCOa, Fe retention was 68% at a Ca Fe ratio of 60 1, and only declined a furfher 2% when the ratio was increased to 120 1. Fe retention values for ofher forms of Ca at a 60 1 Ca Fe ratio were as follows 77% for bone meal, 89% for CaP, and 99% for CaHA. Fe retention decreased in response to the higher Ca Fe ratio of 120 1 (i.e., Fe retention in the presence of bone meal, CaHA, and CaP was 49%, 72%, and 78%, respecfively). This is indicative of a dose-response effect of Ca on Fe retention. This sfudy also underscored fhe importance of the source of Ca in relation fo Fe refenfion. 

If asthma control is not optimal, conventional advice was to increase the ICS dose. However, it is now apparent, that the dose-response effect of ICS is rather flat, so that there is little improvement in lung function after doubling the dose of inhaled steroid. An alternative strategy is to add some other class of controller drug. Several studies have shown that the combination of ICS and salmeterol or formoterol was more effective than increasing the dose of inhaled corticosteroid in terms of lung function improvement, rescue /32-agonist use, symptom control, and frequency of mild and severe asthma exacerbations. 

Dental or enamel fluorosis is an irreversible dose-response effect caused by fluoride ingestion during the pre-eruptive development of teeth. The pre-eruptive maturation of crowns of the anterior permanent teeth, which are of most concern aesthetically, is complete and, together with the risk of fluorosis, is over by the age of 7-8 years [46,47]. After the enamel has completed its pre-eruptive maturation, it is no longer susceptible. Therefore, fluoride intake up to the age of 7-8 years is of most interest. Although it is usually the permanent teeth that are affected, occasionally the deciduous teeth may be also involved. 

Rapport, M.D., Stoner, G., DuPaul, G.J., Kelly, K.T., Tucker, S.B., and Shroeler, T. (1988) Attention deficit disorder and methylphenidate a multilevel analysis of dose-response effects on children s impulsivity across settings. J Am Acad Child Adolesc Psychiatry 27 60-69. 

Tannock, R., Schachar, R.J., Carr, R.P. and Logan, G.D. (1989) Dose-response effects of methylphenidate on academic petfot-mance and overt behavior in hyperactive children. Pediatrics 84 648-657. 

Wang, J.F., Schramm, D.D., Holt, R.R., Ensunsa, J.L., Fraga, C.G., Schmitz, H.H., and Keen, C.L., A dose-response effect from chocolate consumption on plasma epicatechin and oxidative damage, J. Nutr., 130, 2115S, 2000. 

Setchell KDR, Brown NM, Deal PB et al. Bioavailability, disposition and dose-response effects of soy isoflavones when consumed by healthy women at physiologically typical dietary intakes. J. Nutr. 133, 1027-1035,2003. 

Josselson, J., Sidell, F.R. 1977. Dose-response effects of Intravenous thiamine hydrochloride on pralldoxlme pharmacokinetics in man. EB-TR-76117. 

A trial comparing daily doses of 50,100 and 200 mg sertraline with placebo for 12 weeks in patients with panic disorder. No consistent evidence of a dose response effect was found because all three doses of sertraline produced significant efficacy compared with placebo and, surprisingly, there was no significant between-dose difference with regard to discontinuations due to adverse events (Asheikh et ul., 2000). 

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