Inhibition of murine relapsing experimental autoimmune encephalomyelitis by immune tolerance to proteolipid protein and its encephalitogenic peptides.

Tolerization of SJL/J mice with splenocytes coupled with proteolipid protein (PLP), the major protein component of central nervous system myelin, resulted in dramatic inhibition of relapsing experimental autoimmune encephalomyelitis (R-EAE) induced by mouse spinal cord homogenate (MSCH). Mice tolerized with splenocytes coupled with MSCH (a complex mixture of neuroantigens) or with purified PLP, but not purified myelin basic protein, were resistant to the development of clinical and histologic R-EAE. In addition, mice rendered tolerant to an encephalitogenic peptide of PLP were significantly protected, whereas mice tolerized to a nonencephalitogenic peptide of PLP were highly susceptible, to the induction of MSCH-induced R-EAE. Thus, immune responses directed against encephalitogenic regions of PLP appear to play a major role in the development of R-EAE induced by MSCH in SJL/J mice. These results also indicate that determinant-specific immune tolerance is a feasible approach to the regulation of a disease that involves autoimmune responses to a variety of Ag.     

Acute experimental allergic encephalomyelitis in radiation bone marrow chimeras between high and low susceptible strains of mice

Acute experimental allergic encephalomyelitis (EAE) is an autoimmune disease involving the central nervous system (CNS) that can be elicited in susceptible strains of mice by the subcutaneous inoculation of mouse spinal cord homogenate (MSCH) in conjunction with complete Freund's adjuvant. In order to localize the physiological compartment conveying susceptibility to mice for EAE induction, hematopoietic radiation chimeras were prepared between the highly responsive SJL and low responder B10.S strains. Upon challenge with SJL MSCH preparations, high incidence of clinical disease was exhibited by B10.S SJL chimeras but not by SJL B10.S mice, suggesting that non-bone-marrow-derived factors were influencing development of disease. The incidence of histological lesions in the CNS was high for virtually all experimental and control groups except normal B10.S and B10.S B10.S reconstituted mice. In contrast, challenge with B10.S MSCH induced a high clinical incidence of EAE in both B10.S SJL and SJL B10.S chimeras, indicating a possible interstrain difference in the immunogenicity of relevant CNS antigens.Abbreviations used in this paper APC antigen-presenting cell - C complement - CFA complete Freund's adjuvant - CNS central nervous system - EAE experimental allergic encephalomyelitis - MBP myelin basic protein - MHC major histocompatibility complex - MSCH mouse spinal cord homogenate - PBS phosphate-buffered saline     

Covalent complexes of albumin with serotonin, ketanserin and lysergic acid antagonize the activity of serotonin in human platelets

Covalent conjugates of bovine serum albumin (BSA) and 5-HT, ketanserin or d-lysergic acid were synthesized and characterized by polyacrylamide gel electrophoresis, whole blood clearance experiments in mice and aggregation studies with human platelets. Using the standard synthesis procedure, each mol of BSA bound 13.4 mol of [3H]5-HT. Derivatization did not cause significant protein aggregation as determined by electrophoresis. All three conjugates antagonized the ability of 5-HT to amplify aggregation caused by low concentrations of ADP. The antagonist activity of each conjugate was concentration dependent; 2.6 microM 5-HT-BSA completely inhibited the aggregation caused by 13 microM 5-HT. None of the BSA drug conjugates, including 5-HT-BSA, amplified platelet aggregation caused by ADP in the absence of 5-HT. Aggregation by ristocetin, collagen, epinephrine or ADP alone was not significantly affected by the conjugates. Whole blood elimination experiments in mice demonstrated that the three conjugates and underivatized BSA are equally stable in the circulation. These prototypic 5-HT drug-protein conjugates may be useful for probing 5-HT2 receptor-ligand interactions in human platelets.     

Preservation of polyclonal antibody production by hybridization

The fusion of unimmunized (Balb/c × SJL)_F1, mouse spleen cells in which a polyclonal response had been induced by bacterial lipopolysaccharide with a myeloma cell line resulted in hybrid cell populations. The hybrid populations obtained elaborated antibody activity to human hemoglobin A, Keyhole Limpet hemocyanin, the dinitrophenyl (DNP) hapten, and human erythrocytes, Thus, hybridization allowed preservation of the normally transitory polyclonal response induced in mouse B cells by lipopolysaccharide. Furthermore, monospecific production of anti-DNP antibody was successfully factored out of the polyspecific production of antibodies by cloning. The expansion and subsequent injection of one of these clones into a (Balb/c × SJL)_F1 mouse resulted in the formation of an antibody-producing tumor that was successfully passed to other (Balb/c × SJL)_F1 recipients. Collection of the serum from tumor-bearing mice provided useful quantities of an anti-DNP antiserum without resort to any program of immunization whatsoever.     

Effect of the enterotropic carcinogen 1,2-dimethylhydrazine on the level of biogenic amines in the hypothalamus of rats]

The hypothalamic levels of noradrenaline (NA), dophamine (DA), serotonine (5-HT), 5-hydroxyindolacetic acid (5-HIAA) were found to be decreased in male rats 24 hours after subcutaneous injection of 1,2-dimethylhydrazine (SDMH) in a dose of 21 mg/kg. During 3 to 12 hrs after the SDMH treatment the hypothalamic level of NA was decreased, whereas the 5-HT turnover became greater. The hypothalamic histamine level increased 30 min after the SDMH injection only. In the brain stem and the great hemispheres the biogenic amine level displayed no significant changes under the effect of SDMH. The endocrine-metabolic changes due to the selected SDMH effect on the hypothalamic biogenic amine level are supposed to be of great significance in the realization of the carcinogenic action of SDMH in rats.     

Post-mortem changes of neurotransmitter concentrations in the rat brain regions

Using High Performance Liquid Chromatography coupled with electrochemical detection the post-mortem stability of noradrenaline (NA), dopamine (DA), serotonin (5-HT) and 5-hydroxy indole acetic acid (5-HIAA) were examined in the rat hypothalamus, amygdala, cerebral cortex, cerebellum and corpus striatum over an 8 hour time period. Changes in concentrations of the different neurotransmitters were less than it might be expected. The significant changes were: a. A fall in NA levels in the cerebral cortex by 4 hours and in the hypothalamus at 8 hours. b. A reduction in DA concentrations in the corpus striatum at 8 hours but a two fold rise of levels in the hypothalamus at 1 and 2 hours. c. A four-fold increase in 5-HT concentrations in the amygdala throughout the 8 hours studied. The results indicate that for comparative studies on post-mortem brain tissue correction factors should be employed to take into account differential changes in the concentrations of the various neurotransmitters.     

Ventricular Cerebrospinal Fluid Monoamine Transmitter and Metabolite Concentrations Reflect Human Brain Neurochemistry in Autopsy Cases

Concentrations of dopamine (DA), its metabolites 3-methoxytyramine and homovanillic acid (HVA), noradrenaline (NA), its metabolites normetanephrine (NM) and 3-methoxy-4-hydroxyphenylglycol (MHPG), 5-hydroxytryptamine (5-HT, serotonin), and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) were measured in 14 brain regions and in CSF from the third ventricle of 27 human autopsy cases. In addition, in six cases, lumbar CSF was obtained. Monoamine concentrations were determined by reversed-phase liquid chromatography with electrochemical detection. Ventricular/lumbar CSF ratios indicated persistence of rostrocaudal gradients for HVA and 5-HIAA post mortem. Ventricular CSF concentrations of DA and HVA correlated positively with striatal DA and HVA. CSF NA correlated positively with NA in hypothalamus, and CSF MHPG with levels of MHPG in hypothalamus, temporal cortex, and pons, whereas CSF NM concentration showed positive correlations with NM in striatum, pons, cingulate cortex, and olfactory tubercle. CSF 5-HT concentrations correlated positively with 5-HT in caudate nucleus, whereas the concentration of CSF 5-HIAA correlated to 5-HIAA levels in thalamus, hypothalamus, and the cortical areas. These data suggest a specific topographic origin for monoamine neurotransmitters and their metabolites in human ventricular CSF and support the contention that CSF measurements are useful indices of central monoaminergic activity in man.     

Two-way avoidance and acute shock stress induced alterations of regional noradrenergic, dopaminergic and serotonergic activity in Roman high- and low-avoidance rats

Various brain regions of male RHA/Verh and RLA/Verh rats were dissected out and deep-frozen immediately after 30 min in a shuttle box involving a) no shock (control), b) 40 inescapable shocks or c) 40 avoidable shocks. The RHA/Verh rats used in the "c" category exhibited about 80-85% learned avoidance. 5-HT, 5-HIAA, NA, MHPG-SO4, DA, DOPAC and HVA levels were subsequently measured in selected regions. NA levels were considerably reduced in the hypothalamus and pons/medulla of both selected lines of rats after acute shock stress, supporting the results of numerous studies which have indicated that NA turnover is nonspecifically increased by all types of stress, at least in those regions. An increase in cortical MHPG-SO4 and a reduction in hypothalamic 5-HT seen after avoidance learning also occurred after shock stress in RHA/Verh rats. Whereas RLA/Verh rats showed an increased metabolism of 5-HT in the hypothalamus and pons/medulla after shock stress, RHA/Verh rats showed the opposite response in the hypothalamus after the same treatment. A reduction in 5-HT metabolism was also evident in RHA/Verh rats, after avoidance learning, in the cortex, hippocampus and hypothalamus. These results indicated, pending further studies regarding, for example, possible genetic differences in tryptophan uptake and utilization, that 5-HT probably plays at least a modulatory role in the reaction to stress, and in avoidance behavior. That role may be either active or passive, depending upon the emotional status of the subjects. In regard to the DA responses measured in striatum and hypothalamus of the two rat lines, some divergent inter-treatment tendencies, as well as some similarities, were seen in DA metabolism in both regions, but almost none of the differences were significant.     

Characterization of T cell lines and clones from SJL/J and (BALB/c x SJL/J)F1 mice specific for myelin basic protein

Lines of thymus-derived lymphocytes reactive against bovine myelin basic protein (BP) were established in vitro from SJL/J mice. These lines are stable in long-term culture and mediate inflammatory central nervous system (CNS) lesions and a low incidence of clinical experimental allergic encephalomyelitis (EAE) when injected into recipient SJL/J mice. The line cells proliferate in response to BP of bovine, rat, or mouse origin. Clones were derived from these lines, and the characteristics of these clones were analyzed. The clones express Thy-1, Ly-1, and L3T4 antigens and are negative for Ly-T2. The clones all proliferate in response to bovine BP, with different clones showing varying degrees of cross-reactivity between bovine, rat, and mouse BP. The proliferative response is MHC-restricted; antigen-presenting cells from I-As strains are required. Compatible with their phenotype as helper cells, some of the clones will provide help to primed B cells stimulating antibody production in an in vitro assay. When injected into recipients pretreated with pertussis and irradiation, clones that showed proliferation to mouse BP induced the development of inflammatory lesions in the CNS, with mortality of 28% of the recipients. T cell lines were also established in (BALB/c x SJL/J)F1 mice. In contrast to the homozygous SJL/J lines, these lines were highly encephalitogenic, inducing a high incidence of clinical and histologic EAE when injected in vivo.     

Selective reduction by isolation rearing of 5-HT1A receptor-mediated dopamine release in vivo in the frontal cortex of mice

Serotonin (5-HT)1A receptors modulate in vivo release of brain monoaminergic neurotransmitters which may be involved in isolation-induced aggressive behavior. The present study examined the effect of isolation rearing on the 5-HT1A receptor-mediated modulation of dopamine (DA), 5-HT and noradrenaline (NA) release in the frontal cortex of mice. The selective 5-HT1A receptor agonist (S)-5-[-[(1,4-benzodioxan-2-ylmethyl)amino]propoxy]-1,3-benzodioxole HCl (MKC-242) increased the release of DA and NA and decreased the release of 5-HT in the frontal cortex of mice. The effect of MKC-242 on DA release was significantly less in isolation-reared mice than in group-reared mice, while effects of the drug on NA and 5-HT release did not differ between both groups. The effect of the other 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin on cortical DA release was also less in isolation-reared mice than in group-reared mice, and that of the drug on cortical 5-HT release did not differ between both groups. In contrast to MKC-242-induced DA release, amphetamine-induced increase in cortical DA release in vivo was greater in isolation-reared mice. The present findings suggest that isolation rearing enhances the activity of cortical dopaminergic neurons and reduces selectively the 5-HT1A receptor-mediated release of DA in the cortex.     

Effects of 6-methoxy-1,2,3,4-tetrahydro-beta-carboline and yohimbine on hypothalamic monoamine status and pituitary hormone release in the rat

Shortly after administration of 6-methoxy-1,2,3,4-tetrahydro-beta-carboline (6-MeOTHBC) and yohimbine to normal or hypothyroid rats [the latter exhibiting chronically elevated levels of serotonin (5-HT) neuronal activity in the hypothalamus] there was a highly significant increase in hypothalamic noradrenaline (NA) activity and in ACTH release concomittant with a reduction in hypothalamic 5-HT activity (P less than 0.01) and in growth hormone (GH) (P less than 0.01) and in thyroid stimulating hormone (TSH) (P less than 0.01) release from the pituitary. Both compounds caused an increase in hypothalamic dopamine (DA) metabolism and in pituitary prolactin (PRL) release in normal rats (P less than 0.01) but only yohimbine exerted this action in hypothyroid rats. Lower doses of 6-MeOTHBC exerted a relatively specific effect in hypothyroid rats, reducing (P less than 0.01) 5-HT neuronal activity in parallel with pituitary TSH secretion (P less than 0.05). While gross effects of 6-MeOTHBC and yohimbine were similar with respect to their effects on NA and 5-HT status in the hypothalamus, there were quantitative differences. 6-MeOTHBC always caused a greater decrease in 5-HT turnover and a lesser increase in NA turnover than did yohimbine. On the basis of these studies we suggest that the effect of tetrahydro-beta-carboline-related alkaloids on pituitary hormone release may be due to their influence on hypothalamic monoamine status and the subsequent alteration of the hypothalamic-pituitary control system.     

不同周龄Balb/c小鼠脏器质量及其变化趋势分析

目的:测定不同周龄Balb/c小鼠主要脏器质量、脏器系数,并进行比较。方法:取120只3周龄、5周龄、7周龄的Balb/c小鼠,雌雄各半,精确测量小鼠体重和主要脏器质量,计算脏器系数。结果:①雌性与雄性Balb/c小鼠脏器质量相比较:3周龄时肝、脾有显著差异(P0.05);5周龄时肝有非常显著差异(P0.01),脾、肺有显著差异(P0.05);7周龄时肝、肺及双肾有非常显著差异(P0.01),心、脾有显著差异(P0.05)。②雌性与雄性Balb/c小鼠脏器系数相比较:3周龄时肝、脾有显著差异(P0.05);5周龄时肝、脾有非常显著差异(P0.01),膀胱有显著差异(P0.05);7周龄时肺、双肾有非常显著差异(P0.01),脾、膀胱有显著差异(P0.05)。结论:随着周龄的增长,Balb/c雌、雄性小鼠之间,存在差异的脏器也在增多。     

Chronic Alterations in Monoaminergic Cells in the Locus Coeruleus in Orexin Neuron-Ablated Narcoleptic Mice

Narcolepsy patients often suffer from insomnia in addition to excessive daytime sleepiness. Narcoleptic animals also show behavioral instability characterized by frequent transitions between all vigilance states, exhibiting very short bouts of NREM sleep as well as wakefulness. The instability of wakefulness states in narcolepsy is thought to be due to deficiency of orexins, neuropeptides produced in the lateral hypothalamic neurons, which play a highly important role in maintaining wakefulness. However, the mechanism responsible for sleep instability in this disorder remains to be elucidated. Because firing of orexin neurons ceases during sleep in healthy animals, deficiency of orexins does not explain the abnormality of sleep. We hypothesized that chronic compensatory changes in the neurophysiologica activity of the locus coeruleus (LC) and dorsal raphe (DR) nucleus in response to the progressive loss of endogenous orexin tone underlie the pathological regulation of sleep/wake states. To evaluate this hypothesis, we examined firing patterns of serotonergic (5-HT) neurons and noradrenergic (NA) neurons in the brain stem, two important neuronal populations in the regulation of sleep/wakefulness states. We recorded single-unit activities of 5-HT neurons and NA neurons in the DR nucleus and LC of orexin neuron-ablated narcoleptic mice. We found that while the firing pattern of 5-HT neurons in narcoleptic mice was similar to that in wildtype mice, that of NA neurons was significantly different from that in wildtype mice. In narcoleptic mice, NA neurons showed a higher firing frequency during both wakefulness and NREM sleep as compared with wildtype mice. In vitro patch-clamp study of NA neurons of narcoleptic mice suggested a functional decrease of GABAergic input to these neurons. These alterations might play roles in the sleep abnormality in narcolepsy.     

L-Tyrosine-3-hydroxylase regulation in the brain: genetic aspects

Summary L-tyrosine-3-hydroxylase (TH) is the first and rate limiting enzyme in the biosynthetic pathway of catecholamine neurotransmitters (dopamine, noradrenaline, adrenaline). Implication of dopamine (DA) in various psychopathological phenomena, such as schizophrenia, has considerably contributed to the intensity of investigation of basic biochemical regulation of TH by activation and induction. Here we consider a third, constitutional (genotypic) aspect of regulation and present evidence that differences in mesencephalic (TH/SN), striatal (TH/CS), and hypothalamic (TH/HT) TH activity between virtually isogeneic strains of mice can be explained by segregating genetic factors. Biometrical genetic analysis of progenitor strains and their crosses indicated significant additive gene effects for TH/SN, TH/CS, and TH/HT, whereas dominance effects were statistically non-significant. A monogenic model of inheritance for TH/SN and TH/CS could not be rejected, while more than one gene was indicated for TH/HT. Significant positive phenotypic correlations were found in genetically segregating populations among mesencephalic, striatal and hypothalamic TH activities. This would suggest that some common genetic factors (or linked genes) are involved in the genetic variation of all three traits. A genetic selection experiment to elucidate the cellular and biochemical mechanisms underlying these variations is in progress.     

The effect of active immunization with a conjugate of dopamine and bovine serum albumin on the development of an experimental MPTP-induced depressive syndrome and on the monoamine metabolism in the brain of rats

Active immunization with dopamine conjugated with bovine serum albumin (DA-BSA) or BSA with complete Freund's adjuvant (CFA) partly suppressed the development of the MPTP-induced depressive syndrome in rats preventing the appearance of "behavioral despair" symptoms: increase in immobility time and higher index of depression in forced-swim test. In DA-BSA-immunized rats the content of DOPA, DA, HVA, NA, and 5-HN in caudate putamen and that of NA in the frontal cortex was increased, while in BSA-immunized rats the content of 5-HT in both brain areas and that of DOPAC in the frontal cortex was decreased both in rats with reduced depressive syndrome and in saline control as compared with intact animals a day after the last drug injection. In DA-BSA-immunized rats with reduced depressive syndrome the increase in DA and 5-HT content in caudate putamen was less expressed and DOPAC content was lower than in saline control. In BSA-immunized depressive rats DA content in the frontal cortex was also reduced as compared to control.     

Cellular aspects of tolerance. VII. Inheritance of the resistance to tolerance induction

The half-lives of elimination ($\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$) of ¹³¹I-RGG from the body of normal A or Balb/c animals was much longer than the $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ of SJL mice. At all ages, the $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ of normal hybrids (A × SJL, SJL × A, Balb/c × SJL) was similar to or longer than that of the A or Balb/c parents. Thus, in terms of the $\text{T}\text{1}\text{2}$ of normal animals, the SJL responsiveness to ¹³¹I-RGG appeared to be a recessive trait. Tolerance could be induced in newborn animals and, in terms of $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$, the degree of unresponsiveness at the age of 6 weeks, was the same in A, Balb/c, A × SJL, and Balb/c × SJL animals but was much shorter in SJL mice. Thus, in neonatally induced tolerance, the duration of tolerance was recessive for the SJL type. The average $\text{T}{}_{\mathrm{<mtext>built1</mtext><mtext>2</mtext>}}$ after tolerance induction in 3-week-old hybrids (A × SJL, SJL × A, Balb/c × SJL) was similar to that of the A or Balb/c parent, but by the 8th and 12th week it approached the average $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ of the SJL parent. Comparing 8-week-old hybrids, the average $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ was longest in A × SJL hybrids and identical in SJL × A and Balb/c × SJL mice. An examination of $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ distribution in various 8- and 12-week-old crosses and backcrosses revealed a fairly large proportion of individuals with a $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ which was intermediate between SJL and the other parent. There was a tendency for this number to decrease in 12 weeks as compared to 8-week-old mice. In 8-week-old mice, the number of animals with intermediate $\text{T}{}_{\mathrm{<mtext>built1</mtext><mtext>2</mtext>}}$ was smallest when SJL was the maternal animal [(SJL × A); SJL × (A × SJL); SJL × (SJL × A)]. There was no link between $\text{T}{}_{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ of tolerant animals and either the immunoglobulin allotype (MuAl/MuA2) or the C5 eniotype (MuB1 positive/MuB1 negative).     

Strain differences in basal and post-citalopram extracellular 5-HT in the mouse medial prefrontal cortex and dorsal hippocampus: relation with tryptophan hydroxylase-2 activity

We used the microdialysis technique to compare basal extracellular serotonin (5-HT) and the response to citalopram in different strains of mice with functionally different allelic forms of tryptophan hydroxylase-2 (TPH-2), the rate-limiting enzyme in brain 5-HT synthesis. DBA/2J, DBA/2N and BALB/c mice carrying the 1473G allele of TPH-2 had less dialysate 5-HT in the medial prefrontal cortex and dorsal hippocampus (DH) (20-40% reduction) than C57BL/6J and C57BL/6N mice carrying the 1473C allele. Extracellular 5-HT estimated by the zero-net flux method confirmed the result of conventional microdialysis. Citalopram, 1.25, 5 and 20 mg/kg, dose-dependently raised extracellular 5-HT in the medial prefrontal cortex of C57BL/6J mice, with maximum effect at 5 mg/kg, but had significantly less effect in DBA/2J and BALB/c mice and in the DH of DBA/2J mice. A tryptophan (TRP) load enhanced basal extracellular 5-HT in the medial prefrontal cortex of DBA/2J mice but did not affect citalopram's ability to raise cortical and hippocampal extracellular 5-HT. The impairment of 5-HT synthesis quite likely accounts for the reduction of basal 5-HT and the citalopram-induced rise in mice carrying the mutated enzyme. These findings might explain why DBA/2 and BALB/c mice do not respond to citalopram in the forced swimming test. Although TRP could be a useful strategy to improve the antidepressant effect of citalopram (Cervo et al. 2005), particularly in subjects with low 5-HT synthesis, the contribution of serotonergic and non-serotonergic mechanisms to TRP's effect remains to be elucidated.     

不同周龄Balb／c小鼠脏器质量及其变化趋势分析

目的：测定不同周龄Balb／c小鼠主要脏器质量、脏器系数,并进行比较。方法：取120只3周龄、5周龄、7周龄的Balb／c小鼠,雌雄各半,精确测量小鼠体重和主要脏器质量,计算脏器系数。结果：①雌性与雄性Balb／c小鼠脏器质量相比较：3周龄时肝、脾有显著差异（P〈0．05）;5周龄时肝有非常显著差异（P〈0．01）,脾、肺有显著差异（P〈0．05）;7周龄时肝、肺及双肾有非常显著差异（P〈0．01）,心、脾有显著差异（P〈0．05）。②雌性与雄性Balb／c小鼠脏器系数相比较：3周龄时肝、脾有显著差异（P〈0．05）;5周龄时肝、脾有非常显著差异（P〈0．01）,膀胱有显著差异（P〈0．05）;7周龄时肺、双肾有非常显著差异（P〈0．01）,脾、膀胱有显著差异（P〈0．05）。结论：随着周龄的增长,Balb／c雌、雄性小鼠之间,存在差异的脏器也在增多。