Histamine levels, blood

Histamine in the Blood. After its release, histamine diffuses rapidly into the blood stream and surrounding tissues (12). Histamine appears in blood within 2.5 min after its release, peaks at 5 min, and returns to baseline levels by 15 to 30 min. In humans, the diurnal mean of plasma histamine levels is 0.13 ng/g. In urine, elevations of histamine or metaboUtes are more prolonged than plasma elevations. Consequendy, abnormahties are more easily detected by urinary histamine assay. About one-half of the histamine in normal blood is in basophils, one-third in eosinophils, and one-seventh in neutrophils the remainder is distributed among all the other blood components. Increases in blood histamine levels occur in several pathological... 

Watanabi, H., Mochizaki, T., and Maeyama, K. (1996) Transient increase of blood histamine level induced by pentagastrin. Continuous monitoring by in vivo microdialysis, Scand. J. Gastroenterol. 31 1144-1150. 

Low blood histamine levels are observed during pregnancy (Clemetson, 1980), a reflection of increased histamine catabolism by placental DAO (Bardsley et al.. 

If histamine degradation is a physiological function of vitamin C, it is necessary to delineate the tissue level of ascorbic acid required for this effect. In the rat, which is capable of synthesizing ascorbic acid, serum ascorbic acid rose from 1.10 mg/100 ml to 1.63 mg/100 ml within 30 min of immobilization stress, nearly a 50% increase (Nakano and Suzuki, 1984). Liver ascorbate in these animals fell significantly after 15 min of stress, then rose dramatically to over 60% of the initial value within the next 15 min, indicating elevated hepatic biosynthesis of the vitamin. Adrenal ascorbic acid stores fell to 50% of the initial value following immobilization stress, and these levels remained depressed at 4 hr post-stress. Blood histamine levels rose 80%, from 38 to 68 ng/ml, peaking at about 30 min post-stress (Nakano and Suzuki, 1984). Hence, in the rat, stress induced a rapid rise in serum ascorbate which was fueled by ascorbic acid mobilized from tissue stores and by hepatic synthesis of ascorbate. 

Mean ( SEM> Plasma Vitamin C and Blood Histamine Levels in Healthy Adults with and without Vitamin C Supplementation ... 

Although it is well documented in humans and guinea pigs that exogenously administered vitamin C lowers blood histamine levels in vivo (Clemetson, 1980 Chatterjee et al., 1975 Johnston et al., 1992a,b), more research is needed to determine the physiological benefit of this effect, particularly under stress conditions. However, there are several reports in the recent literature indicating beneficial effects of supplemental vitamin C, which can be related to the vitamin s antihistamine effect. 

Friedman, A. H. 8r Walker, C. A. (1969). Rat brain amines, blood histamine and glucose levels in relationship to circadian changes in sleep induced by pentobarbitone sodium. J. Physiol. 202, 133-46. 

Figure 4.4. Plasma histamine levels in response to NT given at t = 0. Rats were anaesthetized and NT (5 nmol/kg) or saline (0-3 ml) given intravenously. Blood was collected at the indicated times. Mean S.E.M. of mean of n values (in parentheses). Horizontal arrow is the histamine level before NT.

In Vivo Human Studies. Increased histamine levels have been reported in the blood of both cotton and flax dust exposed... 

Cotton dust extracts have been shown to affect cyclic nucleotide levels (122). Guinea pig lungs, in response to AECD, show a decrease in cAMP levels with a concomitant increase in cGMP. Further, there is a high correlation (r = 0.95) between lung histamine levels and cAMP/cGMP ratios. Other workers (123) have shown stimulation of cAMP in human peripheral blood lymphocytes in response to AECD. 

Although nicotinic acid and nicotinamide function identically as vitamins, their pharmacologic effects differ. In large doses (up to 6 g/day), nicotinic acid is effective in reducing serum lipids (low-density lipoprotein [LDL], high-density lipoprotein [HDL], triglycerides, and lipoprotein A. Nicotinic acid produces vasodilation and increased blood flow due to histamine release. Nicotinamide does not affect blood lipid levels or the cardiovascular system. 

HI receptors occur throughout the CNS with particularly high densities in the thalamus and hippocampus and are thought to mediate arousal effects of histamine. H2 receptors are concentrated in the striatum, hippocampus and thalamus and H3 receptors in cortex, hippocampus and amygdala. Histamine levels diminish during sleep and HI antagonists which cross the blood brain... 

Weinberg DS, Burnham D, Berlin JA. Effect of histamine-2 receptor antagonists on blood alcohol levels a metaanalysis. J Gen Intern Med 1998 13(9) 594-9. 

In humans the allergic reactions from contrast media resemble those elicited by histamine injection, and the unpleasant side effects are rarer after fast injection than after slow injection of the same dose of contrast medium (489). Seidel et al. (724) showed that usual doses of chemically different contrast media were able to affect the plasma histamine levels in venous blood of healthy persons. Histamine release ceases when the dose rate is reduced to 0.17 g kg min This may explain the advantage of administering urographic agents by infusion to avoid reactions. 

Figure 4. Histamine levels in the circulating blood of three dogs after iv injection of 0.1 mg/kg histamine in the control experiment (O) and 4 hr after the oral administration of 10 mg/kg oxatomide (0)...

Holtmann G, Singer MV. Histamine H2 receptor antagonists and blood alcohol levels. Dig DisSci 9%%) 33, 767-8. 

Holtmann G, Singer MV, Knop D, Becker S, GoebeU H. Effect of histamine-H2-receptblood alcohol levels. Gastroenterology (1988) 94, A190. (abs). 

Table 8.4 Monitoring cutaneous mast cell degranulation in vivo in humans. Histamine levels in venous blood following intradermal challenge with histamine, morphine, and antigen...

---