Biomedical subjects

T Nagaya

Publications and source records attributed to T Nagaya.

At least 55 records · Page 3Linked to original sources

PubMed1997

Nuclear receptor corepressors activate rather than suppress basal transcription of genes that are negatively regulated by thyroid hormone.

A group of transcriptional cofactors referred to as corepressors (CoRs) were recently shown to play a central role in basal silencing of genes that contain positive triiodothyronine (T3) response elements. In a reciprocal manner, negatively regulated genes are stimulated by unliganded thyroid hormone receptor (TR) and repressed upon the addition of T3. We used a TR beta mutant, called P214R, which fails to interact with CoRs, to examine whether CoRs also play a role in the control of genes that are negatively regulated in response to T3. In studies of three negatively regulated genes (the pituitary thyroid-stimulating hormone alpha-subunit [TSH alpha], TSH beta, and hypothalamic thyrotropin-releasing hormone [TRH] genes), stimulation of basal promoter activity by unliganded TR beta was impaired by introducing the P214R CoR mutation. Coexpression of each of the CoRs SMRT (silencing mediator for retinoid receptors and TRs) and NCoR (nuclear receptor CoR) enhanced basal stimulation of the negatively regulated promoters in a TR-dependent manner, but this effect was not seen with the P214R TR mutant. The mechanism of CoR effects on negatively regulated promoters was explored further with a series of GAL4-TR chimeric receptors and mutants that allowed TR effects to be assessed independently of receptor interactions with DNA. These experiments revealed that, like the negative regulation of genes by wild-type TR, basal activation occurred with GAL4-TR, but not with the GAL4-P214R mutant, and was reversed by the addition of T3. These results suggest that TR interactions with negatively regulated genes may be driven through protein-protein interactions. We conclude that a subset of negatively regulated genes are controlled by a novel mechanism that involves TR-mediated recruitment and basal activation by SMRT and NCoR. Addition of T3 reverses basal activation, perhaps by dissociation of CoRs.

Cell Line↗

PubMed1996

Heterodimerization preferences of thyroid hormone receptor alpha isoforms.

Thyroid hormone receptors (TRs) are members of the steroid hormone receptor superfamily and are encoded by two different genes, alpha and beta. Three isoforms (alpha 1, alpha 2, and alpha 3) are created by alternative splicing of the TR alpha gene. In TR alpha 2 and alpha 3, the distal half of the putative dimerization domain is disrupted and the carboxy terminus of the protein is substituted with different amino acids. To evaluate the properties of these alterations in the dimerization region, DNA binding and dimerization of TR alpha isoforms were studied by electrophoretic mobility shift assays. TR alpha 1 formed a monomer or a homodimer on certain thyroid hormone responsive elements (TREs), whereas TR alpha 2 and alpha 3 did not bind effectively to any of the TREs studied. TR alpha 1 formed a heterodimer with 9-cis retinoic acid receptor alpha (RXR alpha) on all TREs studied. Although TR alpha 2 did not bind as a homodimer, it did bind as a heterodimer with RXR alpha to DR4 and MHC-TRE. TR alpha 3 bound as a heterodimer to a broader repertoire of TREs, including DR4, MHC, ME, and F2-TRE. These results indicate that the alterations in the dimerization region in TR alpha 2 and alpha 3 abrogated homodimer binding, but differentially affected heterodimerization with RXR alpha on various TREs.

Amino Acid Sequence↗

PubMed1996

Second zinc finger mutants of thyroid hormone receptor selectively preserve DNA binding and heterodimerization but eliminate transcriptional activation.

Transcriptional regulation by thyroid hormone is mediated through its nuclear receptors (TRs), which bind to target responsive elements as homodimers or as heterodimers with 9-cis retinoic acid receptors (RXRs). We examined the dimerization and functional properties of TRs containing mutations in the first and second zinc finger regions of the DNA binding domain. Interestingly, a mutation (R158G) in the loop of second zinc finger, or a chimeric mutant in which the second zinc finger of the glucocorticoid receptor (GR) was substituted for that of the TR, did not form homodimer, but still bound as a heterodimer with RXR alpha. Despite the presence of heterodimer formation, these mutants were functionally inactive in transfection assays. We conclude that sequences within the loop of the second zinc finger may play an important role in stability in vivo or transcriptional activation of the TR.

Amino Acid Sequence↗

PubMed1996

Serum lipid profile in relation to milk consumption in a Japanese population.

OBJECTIVE: To investigate relationships between serum lipid profiles, milk consumption and lifestyle, in a Japanese population. METHODS: A cross-sectional study in 12,610 Japanese men aged 30 to 69 years. Serum total-cholesterol (TC), HDL-cholesterol (HDLC), LDL-cholesterol (LDLC), TC/HDLC ratio, and triglycerides (TG) were determined. Milk consumption was classified into "Yes" (3553 men) and "No" (9057 men) groups by a self-administered questionnaire "Do you drink a glass of cow's milk (180 to 200 mL) or more everyday?". Five variables (age, body mass index, habitual exercise, and smoking and drinking habits) were considered confounding factors for the serum lipids. RESULTS: Regardless of age, the "Yes" group had higher levels of serum TC, HDLC and LDLC than the "No" group except for one comparison (HDLC in 50 to 54 year old group). The differences in serum TC (p < 0.001), HDLC (p < 0.001) and LDLC (p < 0.001) between the two groups were significant by ANOVA. However, milk consumption had no significant relations to serum TC/HDLC ratio or TG level. Multivariate models including the five confounding factors confirmed these results, and indicated that the "Yes" group had higher adjusted means of serum TC by 0.079 mmol/L (+1.5%, 5.280 vs. 5.201 mmol/L, p < 0.001), HDLC by 0.018 mmol/L (+1.4%, 1.260 vs. 1.242 mmol/L, p < 0.01), and LDLC by 0.066 mmol/L (+2.0%, 3.382 vs. 3.316 mmol/L, p < 0.001) than the "No" group. CONCLUSION: Milk consumption is part of a lifestyle related to hypercholesterolemia in the Japanese.

Adult↗

PubMed1996

Amino acid substitutions of thyroid hormone receptor-beta at codon 435 with resistance to thyroid hormone selectively alter homodimer formation.

Thyroid hormone action is mediated through its nuclear receptors (TRs), which bind to target DNA sequences [thyroid hormone response element (TRE)] as a homodimer or a heterodimer with 9-cis-retinoic acid receptors. Mutations of TR beta identified in patients with resistance to thyroid hormone (RTH) cluster primarily at two areas separated by the putative dimerization region. Two TR beta mutations were newly found in patients with RTH at codon 435 histidine (H435L and H435Q) close to the dimerization region. Recent crystallographic study suggested that H435 is critical for direct contact with T3. To study how the side-chain charge of amino acids at this position affects receptor characteristics, T3-binding activity, receptor dimerization, transcriptional activity, and dominant negative action were analyzed in two RTH mutants and two additional artificial mutants (H435R and H435E). The T3 binding affinities of all four mutants were below detection. In electrophoretic mobility shift assay using TRE-DR4 or the inverted palindrome (Lap), heterodimer formation of mutant receptors with 9-cis-retinoic acid receptor was similar to that of wild type receptors. However, homodimer formation varied among mutant receptors, especially using TRE-DR4, with a rank order of wild type = H435R > H435Q > H435L > > H435E. In the presence of a basic amino acid at codon 435, homodimer formation was preserved, whereas substitution to neutral or acidic amino acids resulted in decreased homodimer formation. In transient transfection assays using reporter genes under the control of 2xPal-thymidine kinase (TK), DR4-TK, Lap-TK, or TSH alpha promoter, these four mutants were inactive in T3-dependent transcriptional activation. Dominant negative inhibition was similar for all four mutants. These results indicate that 1) newly found TR beta mutations at codon 435 are responsible for RTH; and 2) codon 435 in TR beta is located at a position that can predominantly alter homodimer formation on certain TREs, such as DR4.

Amino Acid Sequence↗

PubMed1996

Dominant inheritance of resistance to thyroid hormone not linked to defects in the thyroid hormone receptor alpha or beta genes may be due to a defective cofactor.

Resistance to thyroid hormone (RTH) is an inherited syndrome of reduced tissue responsiveness to thyroid hormone. To date, all individuals expressing the RTH phenotype have been found to harbor mutations in the thyroid hormone receptor beta (TR beta) gene that impair T3-mediated function. We describe a unique family in which the dominantly inherited RTH is not associated with abnormalities in the TR beta or TR alpha genes, as determined by gene sequencing and linkage analysis. However, affected family members manifest a severe form of RTH, with reduced responses of thyrotrophs and peripheral tissues requiring 8- to 10-fold the normal replacement doses of L-T4 and L-T3. No other endocrine abnormalities were detected. The defect developed de novo in the proposita and was transmitted to her two children of unrelated fathers. As cultured fibroblasts from the proposita responded poorly to T3 despite a normal concentration of TR, other abnormalities in the mediation of T3 action were sought. Nucleotide sequences of the TSH beta promoter, containing thyroid hormone response elements, and TR-interacting protein 1 were normal. Nuclear extracts (NE) of cultured skin fibroblasts from affected individuals of this family were tested for their interaction with normal TR beta and thyroid hormone response elements by the electrophoretic mobility shift assay. NE from the proposita showed a strong additional band compared to NEs from normal individuals and patients with RTH caused by TR beta mutations or deletion. Far Western analysis of NE from the affected daughter hybridized with labeled TR beta demonstrated an additional band that was not seen in NEs from a normal control or patients with TR beta gene defects. It is concluded that the etiology of RTH is not confined to abnormalities in the TR beta gene. An abnormal cofactor with a specific function in the regulation of thyroid hormone action is probably involved in the expression of the RTH phenotype in this family.

Child, Preschool↗

PubMed1996

[Effects of long-term physical training on body composition, cardiovascular function, and serum lipids in mildly obese middle-aged subjects].

To investigate the effects of long-term physical exercise on humans, body composition, cardiovascular function and serum lipids were measured for a training period of 20 months in 8 men and 8 women, aged 36-67 years who were mildly obese. The subjects participated in physical training for 90 minutes about twice a week for 20 months. The intensity of training was at most 60% VO2max for each subject as calculated by karvonen's formula. The results are summarized as follows: (1) Body weight and estimated body fat weight decreased from baseline after the training in both sexes. The percentage decreases in body weight and estimated body fat weight in men were about threefold those in women. (2) Following the training, heart rate, blood pressure and rate pressure product (RPP) at rest had significantly decreased from initial levels in both sexes. (3) Following the training, the physical work capacity at a heart rate of 150bpm significantly increased, and systolic blood pressure at the heart rate of 150bpm significantly decreased from baseline levels in both sexes. (4) Following the training, the serum HDL-cholesterol and HDL-/total-cholesterol ratio significantly increased from baseline, and serum triglycerides and total cholesterol also significantly decreased from baseline levels in both sexes. These results suggest that long-term physical training with moderate intensity improves body composition, cardiovascular function and serum lipids in mildly obese middle-aged men and women, and reduces the risks for coronary heart disease.

Adult↗

PubMed1996

Modification of cultured Madin-Darby canine kidney cells with dietary unsaturated fatty acids and regulation of arachidonate cascade reaction.

Madin-Darby canine kidney (MDCK) cells were modified with dietary unsaturated fatty acids. The effects on the fatty acid composition in each phospholipid class and the formation of prostanoids upon stimulation were studied, from which the specificity of metabolism of individual unsaturated fatty acids and the regulation of arachidonate cascades in the modified cells were discussed. C18 unsaturated fatty acids were preferentially incorporated into phosphatidylcholine (PC) over phosphatidylethanolamine (PE), but arachidonic acid (20:4(n-6)) derived from gamma-linolenic acid (18:3(n-6)) was much more predominant in PE than PC. The fatty acid level in PE ranged from about 26-28% when the cells were modified with 20:4(n-6) or 5,8,11,14,17-eicosapentaenoic acid (20:5(n-3)), indicating the limitation of the storage of the eicosapolyenoic acids. The extra amounts appeared to be stored in PC. 18:3(n-6) was comparable to 20:4(n-6) to raise the level of 20:4(n-6) in PE, but not in PC which had half of 20:4(n-6) in PE. The supplementation of linoleic acid (18:2(n-6)). 18:3(n-6), and 20:4(n-6) caused significant increases in the synthesis of prostaglandin (PG)E2 up to almost the same levels when the modified cells were stimulated with 50 nM PMA and 100 nM A23187 for 24h. The cultured cells modified with eicosapolyenoic acids including 20:3(n-6), 20:4(n-6), and 20:5(n-3) were found to be inhibitory for the induction of PGE2 synthetic activity involving de nova synthesis of PG endoperoxide synthase, suggesting negative feedback regulation of the modified cells.

Animals↗

PubMed1996

Antioxidants inhibit tumor necrosis factor-alpha mediated stimulation of interleukin-8, monocyte chemoattractant protein-1, and collagenase expression in cultured human synovial cells.

OBJECTIVE: To study whether the induction of mRNA for interleukin-8 (IL-8), monocyte chemoattractant protein-1 (MCP-1), and collagenase by tumor necrosis factor-alpha (TNF-alpha) is suppressed by antioxidants in human synovial cells. TNF-alpha has been shown to exert some of its effects by stimulating production of reactive oxygen intermediates in some cell lines other than synovial cells. METHODS: Amounts of mRNA for IL-8, MCP-1, and collagenase were determined by Northern blot analysis. Electrophoretic mobility shift assays were performed for the detection of a transcription factor, nuclear factor-kappa B(NF-kappa B). The concentration of IL-8 in the medium was determined by ELISA. RESULTS: TNF-alpha increased the expression of IL-8, MCP-1, and collagenase mRNA in human synovial cells. NF-KB known to induce IL-8 gene transcription was also increased in nuclear extracts from the synovial cells treated with TNF-alpha. Prior addition of antioxidant, N-acetyl-L-cysteine (NAC) or 2-oxothiazolidine-4-carboxylate (OTC), suppressed TNF-alpha stimulated expressions of IL-8, MCP-1, and collagenase mRNA in a dose dependent manner. Treatment with NAC also suppressed TNF-alpha induced increase in NF-kappa B. The changes of IL-8 in the medium reflected the mRNA levels. Hydrogen peroxide (H2O2) induced the expression of mRNA for the cytokines but not collagenase mRNA, and NAC suppressed the effect of H2O2. CONCLUSION: Our data suggest that TNF-alpha induces expression of proinflammatory cytokines such as IL-8 and MCP-1 through generation of reactive oxygen intermediates and subsequent activation of NF-kappa B in human synovial cells, and the antioxidants may inhibit, at least in part, the activation of NF-kappa B by TNF-alpha. These results indicate that antioxidants such as NAC may be useful in treating rheumatoid arthritis.

Acetylcysteine↗

PubMed1995

Milk consumption decreases activity of human serum alkaline phosphatase: a cross-sectional study.

Since the Japanese have not reached the recommended daily allowance (RDA) for calcium (600 mg), milk is recommended as a Ca-rich food to increase Ca intake and prevent osteoporosis in Japan. To determine whether milk consumption influences Ca/bone metabolism in the Ca-deficient population, relationships between milk consumption and serum alkaline phosphatase (Al-P) activity were analyzed in 3,098 premenopausal and 1,182 postmenopausal women and 13,141 men aged 30 to 69 years. Milk consumption was classified into no/yes groups by a self-administered questionnaire that asked "Do you drink a glass of milk (180 to 200 mL) or more everyday?". Regardless of age or sex, the "yes" group had a lower activity of serum Al-P than the "no" group. Milk consumption decreased the activity to a greater degree in women, especially perimenopausal/postmenopausal women, than in men. These results were confirmed in a multivariate analysis considering age, body mass index (BMI), and smoking and drinking habits as confounding factors. Although menopause obviously increased serum Al-P activity in perimenopausal women, it could not influence the effects of milk consumption on the activity. These results suggest that milk has osteostatic effects on humans via a mechanism different from that of estrogens. Milk consumption, even one glass per day, may be an easy and effective strategy for prevention of osteoporosis in the Ca-deficient population, especially perimenopausal/postmenopausal women.

Adolescent↗

PubMed1995

Dominant negative and DNA-binding properties of mutant thyroid hormone receptors that are defective in homodimerization but not heterodimerization.

Thyroid hormone receptors (TRs) bind to thyroid hormone response elements (TREs) as monomers, homodimers, and heterodimers. Mutations that cause resistance to thyroid hormone (RTH) have proven useful for identifying important functional domains in the receptor. Previous studies have shown that RTH mutants must retain the ability to form heterodimers with RXR to exert dominant negative inhibition of wild-type receptor function. In this report, we examined in detail the dimerization properties, function, and dominant negative activity of RTH mutations at R316H and R338W--two mutations that have a propensity to cause the pituitary form of RTH. These mutants show selective loss of homodimerization, with preservation of heterodimerization with RXR alpha. The selective loss of homodimerization was independent of the orientation of the half sites in the TRE. The R316H mutant was transcriptionally inactive in transient expression assays, consistent with its markedly reduced T3 binding. In contrast, R338W was activated at nanomolar concentrations of T3, precluding quantitative analyses of its dominant negative properties. In cotransfection assays with wild-type TR beta, the R316H mutant functioned in a dominant negative manner to block positively (TRE-pal; DR4) and negatively (TSH alpha) regulated reporter genes, although its inhibitory potential was reduced compared with other RTH mutants. Introduction of the R316H mutation into a receptor containing a potent RTH mutant (G345R) reduced its dominant negative activity to the level of the R316H mutant alone. These results suggest that mutations that alter homodimerization have reduced dominant negative activity for some target genes, a feature that may account, in part, for phenotypic variability in RTH.

Base Sequence↗

PubMed1994

Early renal effects of occupational exposure to low-level hexavalent chromium.

To detect early renal effects of occupational exposure to hexavalent chromium (Cr), urinary total proteins (U-TP), urinary albumin (U-Alb) and urinary retinol-binding protein (U-RBP) were determined in 166 male Cr platers and 106 male controls. The mean employment time in Cr plating for the platers was 12.6 years. Urinary Cr (U-Cr), which was determined as an index of Cr exposure, ranged from "not detected" to 19.91 micrograms/g creatinine in the platers. The U-Cr level was lower than those in other previous studies. Age-adjusted U-TP, U-Alb or U-RBP levels were not different between the platers and the controls. In the platers, a significant positive correlation was found between age-adjusted U-TP and U-Cr, but U-Cr had no significant relation to age-adjusted U-Alb or U-RBP level. Employment time had no effect on any age-adjusted urinary proteins. The Cr exposure may have been too low to induce definite renal dysfunction. Early renal effects of low-level Cr exposure may be mild, and may not be specific to renal function.

Adolescent↗

PubMed1994

Relationships between serum saturated fatty acids and serum total cholesterol and HDL-cholesterol in humans.

To investigate the effects of serum saturated fatty acids (FAs) on human cholesterol metabolism, total-cholesterol (T-C), HDL-cholesterol (HDL-C), T-C/HDL-C ratio, and FA composition [myristic acid (MA, 14:0), palmitic acid (PA, 16:0) and stearic acid (SA, 18:0)] were determined in serum from 115 men and 120 women (20-70 years old). MA, PA and SA were expressed as percentages of serum total FAs. Using multivariate analysis to account for the confounding effects of age, body mass index, drinking, and smoking it was found that SA was negatively correlated with T-C and T-C/HDL-C ratio in both men and women. In men MA was negatively correlated with HDL-C, and in women SA was positively correlated with HDL-C. Although PA was the major component of serum saturated FAs, PA had no significant relation to any cholesterol indices in either sex. These results suggest that serum MA may aggravate and serum SA may improve cholesterol metabolism, thereby influencing the risk for ischaemic heart disease.

Adult↗

PubMed1994

Octreotide treatment results in the inhibition of GH gene expression in the adenoma of the patients with acromegaly.

Seven patients with growth hormone (GH)-secreting pituitary adenoma were treated preoperatively with octreotide (Sandostatin or SMS 201-995; a somatostatin analogue), and were compared with 18 non-treated patients in their clinical courses and adenoma analyses. Octreotide treatment improved the endocrinological data in all 7 cases. The octreotide-treated adenomas were soft and easily removed by suction and curettage. The postoperative normalization of endocrinological data was encountered more often in the octreotide-treated cases than in the non-treated, although the statistical significance was not observed by the limited number of cases. The adenoma tissues were examined with conventional histology and immunohistochemistry, and the amount of GH messenger ribonucleic acid (mRNA) was quantitatively assessed. The studies demonstrated: 1) No fibrosis nor necrosis was observed in the adenomas from the octreotide-treated patients. 2) Immunohistochemistry for human GH revealed no remarkable differences between the octreotide-treated and the non-treated adenomas. 3) The amounts of GH mRNA in the adenoma from the octreotide-treated patients were 4.2 +/- 1.8 (mean +/- SEM; expressed in an arbitrary unit) and were significantly less than those from the non-treated (33.6 +/- 9.1). These data suggest that octreotide inhibits not only GH release from the adenoma but also its biosynthesis.

Acromegaly↗

PubMed1993

Distinct dimerization domains provide antagonist pathways for thyroid hormone receptor action.

Transcriptional regulation by thyroid hormone is mediated through its nuclear receptors, which bind to target response elements as homodimers or as heterodimers with proteins such as retinoid X receptors (RXR). Thyroid hormone response elements exhibit remarkable flexibility in that the receptor binding half-sites can be arranged as direct repeats, inverted repeats, or everted repeats. We report that a limited region at the carboxyl-terminal end of the thyroid hormone receptor differentially contributes to the formation of receptor homo- and heterodimers. The functionally inactive thyroid hormone receptor splicing variant alpha 2, which is altered at the juncture of the homo- and heterodimerization domains, cannot form homodimers. However, alpha 2 can form a heterodimer when bound to half-sites arranged as a direct repeat spaced by 4 base pairs (DR4), but not with other arrangements of response element half-sites. The alpha 2-RXR heterodimer strongly inhibits wild type receptor function mediated by the DR4 element, suggesting that the alpha 2 isoform modulates thyroid hormone action by binding as an antagonist to a subset of response elements.

Amino Acid Sequence↗

PubMed1993

Thyroid hormone receptor dimerization is required for dominant negative inhibition by mutations that cause thyroid hormone resistance.

The syndrome of thyroid hormone resistance (THR) is caused by multiple distinct mutations of the ligand-binding domain of the thyroid hormone beta receptor. Although the mutant receptors are transcriptionally inactive, they inhibit normal receptor function in a dominant negative manner to cause hormone resistance. Because most of the naturally occurring mutations are clustered within two areas that lie on either side of a putative dimerization region, we hypothesized that receptor dimerization was important for dominant negative inhibition. In gel mobility shift assays, two THR mutants (G345R and P453H) formed homodimers as well as heterodimers with the retinoic acid X receptor alpha. In contrast, an artificial mutation (L428R) in one of the hydrophobic heptad repeats of the putative receptor dimerization domain impaired heterodimerization with retoinoic acid X receptor alpha without altering the formation of homodimers. Double mutants containing either of the THR mutations along with the dimerization mutation formed homodimers but not heterodimers, reflecting the properties of the dimerization mutant alone. In transient expression assays using positively (TRETKLuc) or negatively (TSH alpha Luc) regulated reporter genes, the dominant negative activity of the THR mutants was eliminated by the addition of the dimerization mutation. These results support a mechanism for dominant negative activity by THR mutants in which functionally inactive heterodimers bind to DNA to inhibit access by normal receptors.

Amino Acid Sequence↗

PubMed1993

Subclinical and reversible hepatic effects of occupational exposure to trichloroethylene.

To detect early hepatic effects of chronic exposure to low-level trichloroethylene (TCE), serum total cholesterol (T-C), high-density-lipoprotein cholesterol (HDL-C) and activities of three serum enzymes [aspartate aminotransferase (AST), alanine aminotransferase (ALT), and gamma-glutamyl transpeptidase (GGT)] were determined in 148 workers (a cross-sectional study) and in 13 workers (a 2-year follow-up study) occupationally exposed to TCE in air. In the cross-sectional study, three exposure groups were defined by urinary total trichloro-compounds (U-TTC) levels of the workers [low-exposure group (n = 49): U-TTC < 10 mg/g creatinine; moderate-exposure group (n = 56): U-TTC 10- < 100; high-exposure group (n = 43): U-TTC > or = 100]. With increasing exposure levels, T-C (P = 0.143 by ANOVA) and HDL-C (P = 0.080 by ANOVA) slightly increased. The exposure, however, had no effect on the activities of the three serum enzymes. In the follow-up study, the fluctuations in U-TTC were well reflected in subclinical changes in HDL-C, AST, and GGT, but not in T-C or ALT. These results suggest that exposure to low-level TCE influences hepatic functions, affecting cholesterol metabolism rather than causing hepatic cell damage, and that these influences are subclinical and reversible. The increases in HDL-C caused by exposure to low-level TCE may be an example of "chemical hormesis" in humans.

Adolescent↗

PubMed1993

No effects of smoking or drinking habits on salivary amylase.

Nonstimulated and expectorated whole saliva was collected from 166 males and 180 females. To investigate biological effects of smoking and drinking habits on digestive functions in healthy populations, salivary total proteins and amylase activity were determined in the saliva samples. Sex differences in the salivary components were not found. Neither of the two habits had any significant influences on salivary proteins or amylase activity in the subjects. Light to moderate uses of tobacco or alcohol may not influence basal components of saliva.

Adult↗