Spermidine Ratio Research Articles

Biogenic Amines and Polyamines and Total Aerobic Count During Storage of Vacuum-Packaged Porcine Kidney, Liver and Spleen

Biogenic amines and polyamines (cadaverine, histamine, 2-phenylethylamine, putrescine, spermidine, spermine, tryptamine and tyramine) were analysed in vacuum-packaged porcine livers, kidneys and spleens stored at 3°C and 7°C (for up to 6 days) or 0°C (for up to 21 days). Total aerobic count, pH and sensory assessment were done in parallel. While histamine, 2-phenylethylamine and tryptamine concentrations were nearly constant, spermidine and spermine showed a moderately declining trend, irrespective of the storage temperature. Cadaverine, putrescine and tyramine concentrations increased with storage time and temperature. Maximum concentrations at day 21 at 0°C were: 122mg/kg for cadaverine, 207.35mg/kg for putrescine and 63.19mg/kg for tyramine. The correlation of concentrations of the latter three amines and the total aerobic count was ranging from r 0.54 to 0.89. A significant rise in amine concentrations was observed only when the total aerobic count exceeded 6 log10 cfu/g. Concentrations of cadaverine, putrescine and tyramine may be useful to confirm spoilage of vacuum-packaged inner organs. The fraction of the potential food-borne pathogen Aeromonas in high-pH organs (spleen, kidney) during storage was significantly higher than in liver, with low pH. It was observed that the spermine: spermidine ratio of spleen (3:2; weight base) was significantly different from that of liver and kidney (4:1).

Control of Spermidine and Spermine Levels in Rat Tissues by trans-4-Methylcyclohexylamine, a Spermidine-Synthase Inhibitor

In rat tissues, a decrease in spermidine, accompanied by an increase in spermine was induced by the oral administration (once daily for either 1 week or 1 month) of trans-4-methylcyclohexylamine (4MCHA), a spermidine synthase inhibitor. This is similar to the changes observed in polyamine content when cell growth is arrested. The body-weight gain of the rats tended to decrease with increasing doses of 4MCHA. A decrease in spermidine, combined with a moderate increase in spermine, was observed dose-dependently in all of the tissues tested, with a relatively fast clearance of 4MCHA. Manipulating the polyamine content of tissues, by daily administration of 100 mumol 4MCHA for 1 week, made it possible to estimate the effects of simultaneously added spermidine or spermine on endogenous polyamine contents. The altered polyamine levels, obtained after daily administration for 1 week, were maintained during the extended 1-month period, with growth-dependent alteration. The results show it is possible to produce experimental rats with a higher spermine:spermidine ratio than control rats to investigate the physiological significance of spermidine downregulation and spermine upregulation in vivo.

Spermine Synthesis Is Required for Normal Viability, Growth, and Fertility in the Mouse

Spermidine is essential for viability in eukaryotes but the importance of the longer polyamine spermine has not been established. Spermine is formed from spermidine by the action of spermine synthase, an aminopropyltransferase, whose gene (SpmS) is located on the X chromosome. Deletion of part of the X chromosome that include SpmS in Gy mice leads to a striking phenotype in affected males that includes altered phosphate metabolism and symptoms of hypophosphatemic rickets, circling behavior, hyperactivity, head shaking, inner ear abnormalities, deafness, sterility, a profound postnatal growth retardation, and a propensity to sudden death. It was not clear to what extent these alterations were due to the loss of spermine synthase activity, since this chromosomal deletion extends well beyond the SpmS gene and includes at least one other gene termed Phex. We have bred the Gy carrier female mice with transgenic mice (CAG/SpmS mice) that express spermine synthase from the ubiquitous CAG promoter. The resulting Gy-CAG/SpmS mice had extremely high levels of spermine synthase and contained spermine in all tissues examined. These mice had a normal life span and fertility and a normal growth rate except for a reduction in body weight due to a loss of bone mass that was consistent with the observation that the derangement in phosphate metabolism is due to the loss of the Phex gene and was not restored. These results show that spermine synthesis is needed for normal growth, viability, and fertility in male mice and that regulation of spermine synthase content is not required.

Changes in polyamines content associated with zygotic embryogenesis in the Brazilian pine, Araucaria angustifolia (Bert.) O. Ktze.

Changes in the polyamine content were analyzed in different embryo developmental stages and tissues during seed development in the conifer Araucaria angustifolia (Bert.) O. Ktze. Free polyamine contents varied according to the tissue and stage of embryo development, the highest levels occurring in the embryonic axis at the early stages, when putrescine and spermidine were most abundant. The levels of spermidine were higher from the stage where cotyledons arise, whereas putrescine decreases. The putrescine/spermine+spermidine ratio was higher during the initial phases of seed development, corresponding to cell multiplication and elongation, with a decrease in the final stages, corresponding to stabilization of the dry matter content.

Polyamines and central nervous system injury: spermine and spermidine decrease following transient focal cerebral ischemia in spontaneously hypertensive rats

Polyamines (putrescine, spermidine and spermine) are ubiquitous cellular components, but their specific role in central nervous system (CNS) injury has yet to be characterized. CNS injury results in increased activities of ornithine decarboxylase and spermidine/spermine- N 1-acetyltransferase, and accumulation of putrescine. The present study determined the polyamine profile in three models of CNS injury, in two different species (gerbil and rat) and two strains of rats (Sprague–Dawley and spontaneously hypertensive): (1) transient focal cerebral ischemia in spontaneously hypertensive rats (SHR); (2) traumatic brain injury in Sprague–Dawley rats; and (3) transient forebrain ischemia in gerbils. While there was a significant increase in putrescine in all three models, spermine and spermidine levels were unaltered in forebrain ischemia and traumatic brain injury. However, transient focal cerebral ischemia shows depletion of spermine and spermidine levels in injured hemisphere compared to contralateral region. Exogenous spermine significantly restored the spermine as well as spermidine levels in the ipsilateral hemisphere after transient focal cerebral ischemia, but did not alter putrescine levels or the ratio of spermidine to spermine. The loss of spermine in particular, may have several consequences that contribute to ischemic injury, including destabilization of chromatin, decreased mitochondrial Ca 2+ buffering capacity, and increased susceptibility to oxidative stress. Based on our and other studies, we propose a tentative antioxidant mechanism of spermine neuroprotection.

Polyamines and their cellular anti-senescence properties in honey dew muskmelon fruit

Activated oxygen free radicals cause peroxidative damage to all membranes and hasten senescence. Polyamines (PAs) are effective scavengers of these free radicals produced by lipoxygenase (LOX) and phospholipase-D (PL-D). Five days prior to abscission (harvest), ‘Honey Brew’ ( Cucumis melo L. (Inodorus group)) fruit have a change in the ratio of endogenous spermidine (SPD) to putrescine (PUT), from SPD>PUT to SPD<PUT, which coincides with the onset of fruit senescence. Hypodermal-mesocarp tissues from harvested fruit incubated in mannitol with exogenous SPD or spermine, at 0.25 or 0.5 M, had more chlorophyll (less senescence) following 6 or 48 h of darkness than tissues incubated in mannitol without PAs. Polyamine-incubated tissues versus no PA has less membrane peroxidation as indicated by less malondialdehyde production, and LOX and PL-D activities, and less plasma membrane perturbation as indicated by greater H +-ATPase activity, and protein and phospholipid contents. Prolonging the duration of endogenous SPD content, whereby, it is greater then PUT content, in harvested (fully-ripened) ‘Honey Brew’ fruit, could delay melon senescence and promote a longer marketable life.

Polyamine levels in various tissues of rats treated with 3-hydroxy-4-methoxycinnamic acid and 3,4-dimethoxycinnamic acid.

The effects of 3-hydroxy-4-methoxycinnamic acid (3H4MCA) and 3,4-dimethoxycinnamic acid (3,4DMCA) on body weight, organ weight, and the contents of putrescine, spermidine and spermine in 15 different tissues were examined in rats that had been given these compounds for 5 days. In 3H4MCA-treated rats, the weight of the spleen was significantly increased, while none of the other organs showed any significant changes. A diet containing either 3H4MCA or 3,4DMCA should not be taken by patients bearing cancers in the seminal vesicles, spleen or liver, and a diet containing 3,4DMCA should not be taken by patients bearing cancers in the testis, kidney, muscle, small intestine or brain (cortex) because of the significant increases in polyamines, which are associated with a risk of cancer growth, in these tissues. However, a diet containing 3H4MCA is recommended for the management of cancers in the skeletal muscle (femoral), tongue, small intestine (jejunum), stomach, lung and brain based on reductions in polyamines which stimulate tumor growth. A diet containing 3,4DMCA is also recommended for cancer in the prostate, thymus and stomach for the same reason. In addition, a synergic therapeutic effect for the treatment of cancers in these tissues may be anticipated by a combination of such a diet with anti-cancer drugs which reduce polyamine levels. The metastasis of cancers in these tissues may also be inhibited by the reduction of polyamines by these acids. The ratio of spermidine to spermine was significantly higher in the lung of 3H4MCA-treated rats, and lower in the seminal vesicle, thymus, kidney, heart, tongue, stomach and lung of 3,4DMCA-treated rats, than in control rats. The present experiment indicated that cancer patients should pay careful attention to endogenous polyamines in tissues bearing tumors induced by chemicals in ingesta and anti-cancer drugs, in addition to exogenous polyamines.

Production and characterization of a monoclonal antibody specific for the polyamine spermidine and its application in ELISA.

To enable the immunoassay of spermidine in tissue extracts, a monoclonal antibody, JAC-1, specific for free spermidine was raised, using a spermidine-ovalbumin conjugate as immunogen. This antibody was characterized, and found to possess a high degree of specificity for spermidine, with only 4% molar cross-reactivity with spermine. A competitive ELISA using this antibody was developed. This assay is able to detect as little as 10 pmol spermidine extracted from small, circa 10 mg, tissue samples. The assay is unaffected by the presence of up to a 4-fold molar ratio of spermine, whereas the corresponding spermine competitive ELISA is adversely affected by a 0.5-fold molar ratio of spermidine. The spermidine competitive ELISA using JAC-1 was used to estimate the spermidine content of several plant and animal tissue extracts and the results compared with HPLC data. This novel assay is a useful development in the assay of polyamines since, compared to routinely employed HPLC methods, it offers increased convenience, rapidity, and capacity for large numbers of samples.

Therapeutic significance of the polyamine level in tissues of rats treated with adriamycin and cisplatin.

The effects of adriamycin (Adr) and cisplatin on body weight, organ weight, and the contents of putrescine, spermidine and spermine in 15 different tissues were examined in rats that had been given these drugs for 5 days. The weight of the spleen in cisplatin-treated rats, and of the thymus, spleen, kidney and heart in Adr-treated rats showed statistically significant decreases. Neither Adr nor cisplatin should be used to treat cancers in the seminal vesicle, and Adr should not be used to treat those in the large intestine due to significant increases in spermidine and spermine, which are associated with a risk of re-growth. However, Adr is recommended in the treatment of cancers in the thymus, kidney, skeletal muscle (femoral), heart, prostate, testis, liver, small intestine and lung, based on decreases in some of the polyamines, while cisplatin is not recommended in the thymus, kidney, skeletal muscle or heart for the same reason that Adr is not recommended to treat cancers of the large intestine (rectum). The ratio of spermidine to spermine was significantly higher in the skeletal muscle of cisplatin-treated rats and in the small intestine and brain of Adr-treated rats, and was lower in the prostate, seminal vesicle and spleen of Adr-treated rats than in control rats.

Efficient plant regeneration from long-term callus cultures of rice by spermidine

A significant reduction in regeneration potential with increasing age (upto 12months) in rice (Oryza sativa L. cv.TN-1) embryogenic callus cultures was observed. Spermidine, while having an inhibitory effect on plant regeneration in fresh callus cultures, promoted morphogenesis in long-term callus cultures. A massive accumulation of polyamines, particularly putrescine (5-fold) was observed in 12 month old cultures resulting in a change of putrescine /spermidine ratio, which seems to be important for maintaining the morphogenetic response. Application of exogenous spermidine to 12 month old cultures showed increased levels of polyamines and restored the putrescine/spermidine ratio comparable to that found in freshly induced cultures, concomitantly, promoting the plant regeneration via somatic embryogenesis in long-term rice callus cultures.

Polyamine Pattern and Biosynthesis in Zygotic and Somatic Embryo Stages of Vitis vinifera

Summary A comparative study of free polyamine levels, arginine decarboxylase (ADC, EC 4.1.1.19) and ornithine decarboxylase (ODC, EC 4.1.1.17) activities was carried out in the different stages of somatic embryos of Vitis vinifera cv. Grenache noir, and in zygotic embryos of the same cultivar, before and after germination. Somatic embryos showed a high level of free polyamines and a high putrescine/ spermidine ratio. On a per unit basis, an accumulation of putrescine (Put) and spermidine (Spd) occurred in the late torpedo stage, which coincided with the beginning of abnormal growth and disorganized cell proliferation. In globular, heart-shaped and torpedo so matic embryos, ADC activity was higher than ODC activity. Later, in giant somatic embryos, a very high ADC and an even higher ODC activity occurred, except when expressed on a dry weight basis. By contrast, zygotic embryos showed a low level of free polyamines and a Put/Spd ratio approximately equal to one. These data suggest that the abnormal behaviour of grape somatic embryos and their low rate of development into plantlets (

Polyamines of Sulfur-Dependent Archaebacteria and Their Role in Protein Synthesis1

Several strains of the sulfur-dependent archaebacterium, Sulfolobus, were analyzed for their polyamine content. Caldine (norspermidine), spermidine, and thermine were found to be major components in all of the cells tested. The most abundant polyamine in all cultures examined was spermidine. The Langworthy strain had the highest spermine content, whereas S. acidocaldarius strain no. 7 was devoid of this polyamine. Cultures of strain no. 7 grown at 70 degrees C were rich in spermidine and caldine (triamines) and the thermine: spermidine ratio was much lower than that of cultures grown at 78 degrees C. Equal amounts of thermine and spermidine were present in strain DSM 1616. Preincubation of Langworthy strain extracts at 10 degrees C did not overcome the requirement for polyamines in protein synthesis. Putrescine exerted a concentration-dependent inhibition of the spermine-induced stimulation of protein synthesis at 70 degrees C. Increasing concentrations (6 and 9 mM) of spermine and thermine progressively inhibited poly(U)-dependent phenylalanine incorporation at 45 degrees C to about the same extent, whereas the same concentrations of these polyamines had little effect on the reaction at 70 degrees C. Although 3 mM spermine had only a slight stimulatory effect on the attachment of phenylalanine to tRNA at 65 degrees C, this polyamine had a pronounced effect on the formation of 70S ribosomes in a standard buffer containing 10 mM Mg2+. Increasing the Mg2+ concentration to 30 mM in the absence of spermine was even more effective in causing the reassociation of subunits to form 70S particles.

Erythrocyte polyamines of normal individuals and patients with Sickle Cell Anemia (SCA)

Aging of human red cells (RBC) appears to occur as a function of the age of the subject and time which is spent by the erythrocyte in the circulation. In SCA, there is a decrease in the time RBCs circulate. The polyamines, putrescine, spermidine and spermine can alter the electrokinetic properties of red cells. As red cells age, there is a decrease in the surface charge and altered deformability. To assess the effect of time in the circulation on RBC polyamine content of control subjects, we analyzed levels of density fractionated cells of ten healthy donors (HbAA) and compared to levels of four SCA patients (HbSS), ages 26 to 38. Perchloric acid extracts of erythrocyte stroma were analyzed by amino acid analysis using O-phthaldehyde fluorescent detection. At age 50–60 in normal subjects there is an accelerated loss of both spermidine and spermine in the dense cells relative to reticulocytes. This may be related to loss of surface area of the erythrocyte. In the four SCA patients, the spermidine and spermine ratios were similar to that of young normals of the same age group. It is considered that a large fraction of the total polyamines is firmly bound to spectrin. Polyamines may exert a regulatory role in the RBC stroma.

Role of polyamines in intestinal adaptation in the rat.

The cellular mechanisms controlling adaptive intestinal mucosal hypo- and hyperplasia are poorly understood but changes in tissue polyamine levels and in the activity of the key enzymes controlling their synthesis (ornithine decarboxylase: ODC) and degradation (diamine oxidase: DAO) have been implicated. Therefore, in two models of adaptive mucosal hyperplasia (pancreatico-biliary diversion, PBD, achieved by surgically transposing the jejunum to lie between pylorus and ampulla of Vater, and 90% small bowel resection, SBR-both studied 8 weeks after surgery) and in one model of hypoplasia (8 days total parenteral nutrition) we measured indices of mucosal mass (wet weight, protein and DNA per 10-cm intestine), the growth-associated polyamines (putrescine, spermidine and spermine per 10-cm intestine and per mg DNA) and DAO activity in the duodenum, five 10-cm segments of jejunum, five 10-cm segments of ileum and in the colon, and compared the results with those found in transected or unoperated controls. The results for the indices of mucosal mass confirmed that TPN led to a modest degree of small bowel mucosal hypoplasia whilst PBD, and particularly 90% SBR, stimulated marked adaptive hyperplasia. There were corresponding changes in the amounts of putrescine and spermidine (but not of spermine)-not only when the results were expressed per unit length but also when calculated per mg mucosal DNA and in the ratio of spermidine:spermine. There was an increasing proximal-to-distal gradient in mucosal DAO per unit length intestine in all experimental groups but when the results were expressed per mg DNA, the ileal DAO levels were significantly reduced in the PBD and resection groups, when compared with the controls. These data support the hypothesis that polyamines play a major, and perhaps a controlling, role in regulating adaptive intestinal mucosal growth.

Influence of Avian Aflatoxicosis on the Synthesis of Polyamines

Effects were examined of inanition, dietary aflatoxin (2.5 mg/kg), and dietary supplements of threonine, lysine, and arginine on the activities of renal arginase and hepatic ornithine decarboxylase and on the accumulation of polyamines in liver and brain of 24 or 26-day-old broiler cockerels. Aflatoxicosis and inanition lowered the activity of renal arginase by 58 and 37%, respectively. Supplemental dietary threonine (.4%) did not suppress the activity of renal arginase, while fortification of diets of controls with lysine (.53%), but not diets containing aflatoxin, elevated the activity of renal arginase. Supplements of dietary lysine and/or arginine did not influence the hepatic content of putrescine but lowered the concentrations of spermidine and spermine. Aflatoxicosis, but not inanition, increased the activity of hepatic ornithine decarboxylase (ODC; 22-fold), increased hepatic concentrations of putrescine and spermidine, but decreased spermine concentrations. The elevation of hepatic ODC, putrescine, and the ratio of spermidine to spermine parallels the enlargement of the liver caused by aflatoxicosis. Cadaverine and putrescine were not detected in avian brain, while cerebral concentrations of spermidine and spermine were not altered by aflatoxin, inanition, or by supplements of dietary lysine, arginine, or both lysine and arginine.

Erythrocyte polyamine levels during intravenous feeding of patients with colorectal carcinoma

Changes in erythrocyte (RBC) polyamines were studied during total parenteral nutrition (TPN) in 16 colorectal carcinoma patients and six patients with noncancerous diseases. RBC putrescine (PTC), spermidine (SPD), and spermine (SPM) were analyzed before and at the completion of preoperative TPN in each patient. Before TPN, nutritional status, based on a history of weight loss and plasma albumin, prealbumin and retinol-binding protein levels, were similar for the two groups. Initial RBC PTC, SPD, and SPM levels were also similar for both groups. Preoperative TPN induced significant increases in RBC PTC levels ( P<0.001) and RBC PTC:SPD ratios ( P < 0.005) of the cancer patients while no significant polyamine changes were observed in the other group. Host response to nutritional therapy was monitored with plasma prealbumin and retinol-binding protein levels which did not change significantly in either group.

Urinary polyamines for evaluating the course of disease for patients with small cell carcinoma of the lung.

Clinical correlates with urinary excretion of polyamines were evaluated for 29 newly diagnosed and 35 previously treated patients with small cell carcinoma of the lung (SCC). The frequencies of pretreatment abnormalities were 12 (41%) for putrescine, 18 (62%) for spermidine, and 20 (69%) for spermine. In assessing disease parameters, the combined use of the abnormalities of spermidine and spermine as a discriminant was more effective than that of all three polyamines; it correlated significantly with extent of limited and extensive disease (P less than 0.001), and also resulted in significant separation of survival curves, the median survival of 11 months for both elevated compared to 19 months for neither or only one elevated (P = 0.062). No significant difference was seen in the abnormalities between no metastasis and one metastasis, whereas the frequencies of the abnormalities was highly increased in two or more metastases. The distribution of polyamines determined at regular treatment intervals showed distinctively more elevated patterns in progressive disease than in stable disease or partial and complete responses (P less than 0.01). In order to evaluate therapeutic effects on the relationship between polyamine excretion and tumor regression, correlations between urinary putrescine and spermidine were determined. The values of the ratio of spermidine to putrescine were significantly smaller in responders than in nonresponders (P less than 0.01); and these may be related to smaller tumor mass and higher tumor proliferative activity in responders, and larger tumor mass and lower tumor proliferative activity in nonresponders.

Polyamines and Root Formation in Mung Bean Hypocotyl Cuttings

The effect of several polyamines (putrescine, spermidine, and spermine), their precursors (l-arginine and l-ornithine), and some analogs and metabolic inhibitors (l-canavanine, l-canaline, and methylglyoxal-bis [guanylhydrazone]) on root formation have been studied in mung bean (Vigna radiata [L.] Wilczek) hypocotyl cuttings.Exogenously applied polyamines did not promote adventitious root formation. Rooting was inhibited by l-canavanine and l-canaline, and this inhibition was reversed by the corresponding amino acids l-arginine and l-ornithine. Methylglyoxal-bis (guanylhydrazone), an inhibitor of S-adenosylmethionine decarboxylase and polyamine biosynthesis, was also found to inhibit root formation. All compounds at concentrations of >10(-4) molarity completely inhibited natural root formation, whereas at <10(-5) molarity only the indole-butyric acid-induced root formation was inhibited.Indole-butyric acid-induced root formation was accompanied by a considerable increase in polyamine levels, more than 2-fold of the control. Whereas senescing (unrooted) cuttings evinced a rapid decline in polyamine content during 48 hours, indole-butyric acid treatment resulted in elevated levels of putrescine and increased putrescine to spermidine ratio. The changes in polyamines were dependent on indole-butyric acid concentration and were organ specific.

Polyamine synthesis and levels during the growth and replication of Leishmania tropica minor and Leishmania aethiopica

1. Introduction The polyamines putrescine, spermidine and spermine, which occur widely in nature [l-5], are involved in cellular growth processes [6]. At physiol- ogical levels, they stimulate DNA [7], RNA [8] and protein ]9,10] synthesis, and reach their peak levels during periods of maximal growth [I]. They are required for optimal growth in bacteria, where their limitation leads to reduced cellular growth [ 111 and their concentration is markedly increased in rapidly growing mammalian cells [l], with this growth being arrested on inhibition of polyamine synthesis [ 121. It was shown that polyamines also occur in various trypanosomatid protozoa, where they are at their maximal levels during the logarithmic phase of growth [13-l 61. We have demonstrated that some antileishmanial drugs and polyamine analogues, i.e., pentamidine isethionate, ethidium bromide and methyglyoxal-bis (guanyl hydrazone) (MGBG), impair leishmanial growth by interfering with polyamine biosynthesis [ 161. In order to demonstrate the causal relationship between leishmanial growth and polyamine biosynthesis, a correlation between growth rate and putrescine to spermidine ratio must be established. In this study we demonstrate such a correlation. 2. Materials and methods The two strains studied were obtained from the 202 culture collection of the World Health Organisation’s International Reference Centre for Leishmaniasis (WHO-LRC), housed in the Department of Protozoology of the Hebrew University-Hadassah Medical School, Jerusalem. Their origins and some of their intrinsic taxonomic characters are given in table 1. These strains were maintained at 28°C by biweekly passage on semisolid Locke-blood-agar [ 191 or NNN diphasic medium [20]. For experimental studies, the strains were grown in a fully-liquid, Panmede (Paines and Byrne Ltd., Greenford, Middlesex, England) based medium, containing 7.5% normal rabbit blood

Elevated Levels of Polyamines and Histamine in Adenocarcinomas of the Thyroid*

The concentrations of polyamines (putrescine, spermidine, and spermine) and of histamine in normal and diseased thyroids were determined with an automated amino acid analyzer. A total of 39 specimens was investigated: 7 specimens of normal tissue, 6 adenocarcinomas, 2 specimens of tissues adjacent to adenocarcinoma, 13 specimens from treated Graves' disease, 7 follicular adenomas, 2 adenomatous goiters, and 2 specimens of Hashimoto's thyroiditis. Mean putrescine levels in tissues from normal thyroid, adenocarcinomas, Graves' disease, and follicular adenoma were 26, 143, 20, and 12 nmol/g wet tissue, respectively. The mean levels of both spermidine and spermine were slightly but significantly higher in adenocarcinomas than in other thyroid tissues. The molar ratio of spermidine to spermine was about 0.5 both in the normal and diseased thyroid tissues, except for specimens of thyroiditis. Histamine was detected in 3 of the 6 cases of thyroid carcinomas, and in case of adenomatous goiter. The data suggest that measurement of polyamines, especially putrescine, may be useful for diagnosis of thyroid adenocarcinomas.