Concentrations of copper, iron, and zinc in the major organs of the wistar albino and wild black rats: a comparative study

The concentrations of copper, iron, and zinc in the major organs of Wistar albino (Rattus norvegicus) and wild black rats (Rattus rattus) were measured by means of atomic absorption spectroscopy. The copper levels in the kidneys and liver of the Wistar albino rats (WARs) were significantly higher (p<0.05) than in the wild black rats (WBRs). There were no significant differences in the concentrations of zinc in the liver, lungs, kidneys, and brain between the two study groups, but zinc was significantly higher in the spleen (p<0.05) and lower in the heart (p<0.05) of WAR, compared to WBRs. Iron was significantly higher (p<0.05) in the heart and spleen of WBRs, compared to WARs.There were no extreme differences in the organ concentrations of trace elements between the two species, but, cumulatively, the WARs tend to have higher metallic concentrations in their system than the WBRs. The potential of these differences on the experimental results should not be overlooked and will serve as basis to further consider the complex interrelationships of these animals in their microenvironments and macroenvironments.     

Effects of zinc deficiency and pinealectomy on cellular immunity in rats infected with Toxoplasma gondii

The effects of zinc and/or melatonin deficiencies on cellular immunity were investigated in rats infected with Toxoplasma gondii. A total of 50 adult male Sprague-Dawley rats were divided into 5 groups of 10 rats each. In group I, the rats were infected with T. gondii and fed a zinc-deficient diet; in group II, the rats were infected and their pineal gland was surgically removed. Group III included rats that were infected, pinealectomized, and fed a zinc-deficient diet. Group IV consisted of T. gondii-infested rats that received no treatment of any kind, and group V were normal controls. After 3 wk of treatment, all rats were sacrificed and the percentages of CD3, CD4, and CD8 lymphocytes, zinc, and melatonin levels in plasma and the percentage of lymphocyte in blood smears were analyzed. The CD3 ratios of groups I–III were significantly lower than those of groups IV and V (p<0.01). The CD4 lymphocytes were significantly higher in group IV than that in all other groups (p<0.05). In group IV, the CD8 lymphocytes were higher than in groups I–III (p<0.01) and those in group V were higher than for groups I and III (p<0.01). Lymphocyte incidence in group IV was higher than in the other four groups (p<0.01). The plasma zinc and plasma melatonin levels in groups I–III were significantly lower than those in the controls (p<0.01, both cases). These results suggest that zinc and/or melatonin deficiency have a negative influence on cellular immunity in rats with toxoplasmosis.     

Concentrations of cadmium,lead, selenium,and zinc in human blood and seminal plasma

The concentrations of cadmium, lead, selenium, and zinc in blood and seminal plasma were determined in 76 Singapore males. Except for zinc, the concentrations were generally higher in blood than in seminal plasma (cadmium, 1.31 μg/L vs 0.61 μg/L; lead, 82.6 μg/L vs 12.4 μg/L, and selenium, 163.6 μg/L vs 71.5 μg/L). The mean concentration of zinc in seminal plasma was more than 30 times higher than in blood (202 mg/L vs 6.2 mg/L). Significant positive correlations were found between the concentrations in blood and seminal plasma for the two essential trace elements: selenium (r=0.45,p<0.001) and zinc (r=0.25,p<0.05). However, no relationships were found between the concentrations in blood and seminal plasma for two toxic metals (cadmium and lead). Significant inverse correlations were observed between Cd and Zn (r=−0.40,p<0.01), and Pb and Se (r=−0.32,p<0.05) in blood, whereas significant positive correlations were noted between Cd and Se (r=0.45,p<0.01), Cd and Zn (r=0.35,p<0.05), and Se and Zn (r=0.57,p<0.001) in seminal plasma. The physiological significance of these relationships are also discussed in this paper.     

Antioxidant enzyme activities and trace element concentrations in ischemia-reperfusion

In this study, we investigated the impact of ischemia-reperfusion on antioxidant enzyme activities and trace element concentrations. For this purpose, ischemia was initiated by clamping superior mesenteric artery of Wistar (albino) rats for 30 min, followed by reperfusion for 20 min. Immediately after reperfusion, blood samples were taken and examined for red cell copper-zinc superoxide dismutase (Cu-Zn-SOD), catalase (CAT), and glutathione peroxidase (GPx) activities spectrophotometrically and plasma zinc, copper, and magnesium concentrations by atomic absorption spectrophotometer. In the ischemiareperfusion group, red cell Cu-Zn-SOD activity and plasma zinc and copper concentrations were increased significantly (p<0.001) when compared to the control group; however, the increases in GPx activity and plasma magnesium concentration were not significant (p>0.05). We also found a significant (p<0.01) decrease in catalase activity. Free radicals released as a consequence of ischemia-reperfusion caused significant alterations in antioxidant enzymes and in the concentrations of trace elements. Presented at III International Congress of Pathophysiology 1998, Lahti, Finland.     

Effects of Ellagic Acid on Copper,Zinc, and Biochemical Values in Serum and Liver of Experimental Cholestatic Rats

Ellagic acid (EA) is a natural polyphenolic compound. Although, modulator effects of EA on copper (Cu) and zinc (Zn) levels in some liver diseases have been reported in experimental animals, its effects in obstructive jaundice (OJ) has not been clarified. We aimed to evaluate potential effects of EA on Cu and Zn levels in liver and serum of cholestatic rats. Forty Wistar albino rats were equally divided into four groups. First group was used as controls. Second group received EA (60 mg⁻¹ kg⁻¹ day⁻¹) for 8 days. Third was OJ group, and fourth group was OJ plus EA group. After 8 days, blood and liver samples were obtained. Higher serum and liver Cu and lower serum and liver Zn levels were found in OJ group (p < 0.05) compared with other groups. However, these differences reached to significant levels for Cu in serum and for Zn in lever. Higher serum copper levels were decreased, and lower liver Zn levels were increased by EA treatment in cholestatic rats (p < 0.05). Also, higher Cu/Zn ratio in OJ group was decreased by EA treatment both in liver (p < 0.05) and in serum (p < 0.05). Significantly higher serum bilirubin, alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase values were found in OJ and OJ + EA groups compared with the control and EA groups (p < 0.05). In conclusion, result of the current study indicated that ellagic acid has modulator effects on Cu and Zn levels in liver and serum of cholestatic rats.     

Responsivenes of total content changes of magnesium and zinc status in patients infected with Giardia intestinalis

The aim of the study was to investigate the changes of total content of the essential elements of zinc and magnesium levels in patients infected with Giardia intestinalis. Zinc and magnesium concentrations were measured in 64 patients who were positive for the intestinal parasite G. intestinalis. Scores were obtained for the positives and their 60 age- and sex-matched G. intestinalis-negative healthy controls. The mean concentration of magnesium in blood was significantly lower in G. intestinalis-positive patients than in their controls both in females (p<0.05) and males (p<0.05). The average zinc concentration in G. intestinalis-positive female patients was 0.76±0.3 mg/L and it was 0.60±0.2 mg/L in controls (p>0.05). The mean values of the zinc in blood were 0.73±0.2 mg/L in G. intestinalis-positive male patients and 0.82±0.1 mg/L in controls (p>0.05). No correlation could be demonstrated between age and mean values of zinc and magnesium in both G. intestinalis-positive females/males and controls (p>0.05). No significant correlation could be found between blood zinc and magnesium levels in G. intestinalis-positive female/male patients and controls (p>0.05). Magnesium levels were found to be clearly decreased, whereas no change was observed in zinc level in the patients infected with G. intestinalis compared to controls.     

Serum zinc and magnesium levels in patients with blastocystosis

The aim of the study was to investigate the total content of the essential elements of zinc and magnesium levels in patients infected with Blastocystis hominis. Zinc and magnesium concentrations were measured in 52 patients who were positive for the intestinal parasite Blastocystis hominis. Scores were obtained for the positives and their age- and sex-matched 60 Blastocystis hominis-negative healthy controls. For comparison of two groups of continuous variables, the independent samples t-test was used. The mean concentration of magnesium in blood was significantly lower in Blastocystis hominis-positive patients than in their controls both in females (p<0.05) and males (p<0.05). The average zinc concentration in Blastocystis hominis-positive female patients was 0.61±0.2 mg/L and 0.60±0.2 mg/L in controls (p>0.05). The mean values of the zinc in blood were 0.62±0.2 mg/L in Blastocystis hominis-positive male patients and 0.82±0.1 in controls (p>0.05). No correlation could be demonstrated between age and mean values of zinc and magnesium in Blastocystis-positive females/males and controls (p>0.05). No significant correlation could be found between blood zinc and magnesium levels in Blastocystis-positive female/male patients and controls (p>0.05). Magnesium levels were found to be clearly decreased, whereas no change was observed in zinc levels in the patients with Blastocystis compared to controls.     

Effect of zinc and melatonin supplementation on cellular immunity in rats with toxoplasmosis

The effects of zinc (Zn) and/or melatonin supplementation on cellular immunity were investigated in rats infested with Toxoplasma gondii. Fifty Sprague-Dawley male rats were used for this study. All animals were fed a normal diet, ad libitum, containing 97 mg Zn/kg. They were divided into five experimental groups, as follows. Group I (n=10) received intraperitoneal injections of zinc sulfate at a dose of 3 mg/kg/d for 3 wk. Group II (n=10) received intraperitoneal injections of melatonin at a dose of 3 mg/kg/d for 3 wk. Group III (n=10) received intraperitoneal injections of zinc sulfate (3 mg/kg/d) and melatonin (3 mg/kg/d) for 3 wk. Group IV (n=10) was infested controls. Group V (n=10) was healthy controls. There were no differences in the percentage of CD3+ lymphocytes among all groups. For groups I–III, the CD4+ and CD8+ ratios were higher than those of the groups IV and V controls (p<0.01). Similarly, the total lymphocyte ratios in groups I–III were higher than those of infested and healthy controls (p<0.01). The total lymphocyte ratios in group III were significantly higher than those of groups I and II (p<0.01). The plasma Zn levels in the supplemented groups were significantly higher than those of control groups IV and V (p<0.01). These results suggest that melatonin and/or Zn supplementation may activate cellular immunity by stimulating CD4+ and CD8+ production in infected rats with T. gondii.     

Effect of zinc deficiency and supplementation on lipid peroxidation of renal tissue in ovariectomized rats

The aim of this study was to investigate how zinc deficiency and supplementation affects lipid peroxidation in the renal tissue in ovariectomized rats. Four study groups were formed with 10 Spraque-Dawley rats each. Two of the groups served as normal and ovariectomized controls; the other two were ovariectomized rats that were zinc deficient and zinc supplemented, respectively. The zinc-deficient ovariectomized rats showed greater renal and plasma lipid peroxidation, as indicated by higher malondialdehyde levels than all other groups (p<0.05). These values were higher in the ovariectomized controls than those of the normal controls and of the ovariectomized, zinc-supplemented groups (p<0.05), which, in, turn, showed no significant differences of their respective renal and plasma malondialdehyde values. The renal and erythrocyte glutathione levels in the zinc-supplemented rats were higher than those in all other groups (p<0.05). The zinc-deficient group had the lowest renal and erythrocyte glutathione levels (p<0.05). The renal tissue zinc levels in the ovariectomized rats were higher than those in the zinc-deficient animals, but lower than in the normal controls and zincsupplemented rats (p<0.05). The zinc-supplemented animals had the highest renal tissue zinc levels (p<0.05). The results of this study suggest that zinc deficiency increases renal tissue damage in ovariectomized rats and that zinc supplementation can be used to prevent this condition.     

Effects of zinc and melatonin deficiency on testicular tissue of rats

The present study was designed to investigate the effects of zinc and/or melatonin deficiency on rat testes. A total of 24 adult male Sprague-Dawley rats were used in this study. The rats were divided into four groups of six rats each, as follows: (I) controls, (II) zinc deficient, (III) pinealectomized, zinc normal, and (IV) pinealectomized, zinc deficient. The plasma zinc levels in the control group were higher than in all the other groups (p<0.01), and those of the zinc-deficient groups II and IV were significantly lower than for group III (p<0.01). The melatonin levels in the controls were also significantly higher than for all other groups (p<0.01) There was no significant difference in sperm production between the controls and the group of animals that had no epiphysis. A significant suppression was observed in the spermatogenetic activity of the zinc-deficient groups (p<0.01). The suppression was higher in group II than in group IV. These results indicate that testicular damage caused by zinc deficiency may be reduced by melatonin deficiency.     

Effect of long-term swimming exercise on zinc,magnesium, and copper distribution in aged rats

Trace element content of different tissues might be altered by both age and exercise training. We aimed to determine the effects of a 1-yr swimming protocol (60 min/d, 5 day/wk) on tissue levels and the distribution of zinc (Zn), magnesium (Mg), and copper (Cu) in aging rats. Three groups were formed: sedentary and trained old groups and a young control group. Tissue Zn, Mg, and Cu concentrations were measured in the kidney, heart, liver, lungs, and gastrocnemius and soleus muscles. Kidney zinc concentration significantly decreased in the sedentary old group compared to the young control group (p<0.01) and was significantly higher in the trained old group compared to the sedentary old group (p<0.01), whereas Zn levels in the soleus muscle significantly increased in the sedentary old group in comparison to young controls (p<0.05). Tissue Mg concentrations remained unchanged. The sedentary old group exhibited a significant decrease in kidney Cu concentration compared to the young control group (p<0.01). Although kidney Cu levels also decreased in trained old rats in comparison to young controls (p<0.05), they were significantly higher than in sedentary old rats (p<0.01). The decrease in kidney Zn and Cu content as a result of aging was partly prevented by long-term swimming exercise.     

Changes of total content of magnesium and zinc status in patients with chronic toxoplasmosis

The aim of this study was to investigate the effects of the Toxoplasma gondii infection on the total content of the essential elements Zn and Mg levels. Plasma zinc and magnesium concentrations were measured in 158 patients whose anti-T gondii IgG antibodies were positive. Scores were obtained for the patients and their age- and sex-matched 82 sero-negative healthy controls. The mean concentration of Mg in blood was significantly lower in sero-positive patients than in their controls both in females (p<0.01) and males (p<0.01). The average Zn concentration in seropositive female patients was 0.72±0.2 mg/L and 0.65±0.1 mg/L in controls (p>0.05). The mean values of the Zn in blood were 1.00±0.3 mg/L in seropositive male patients and 0.84±0.2 in controls (p>0.05). No correlation could be demonstrated between age and mean values of Zn and Mg in both sero-positive females/males and controls (p>0.05). No significant correlation could be found between blood Zn and Mg levels in seropositive female/male patients and controls (p>0.05). Mg levels were found to be clearly decreased in the patients with chronic toxoplasmosis, whereas no change was observed in Zn levels.     

Dermatophytes and other keratinophilic fungi from coypus (Myocastor coypus) and brown rats (Rattus norvegicus)

The occurrence of mycotic agents was investigated by hair-brush technique on the coat of 162 naturalized coypus (Myocastor coypus) and 64 indigenous brown rats (Rattus norvegicus) originating from the same protected area in Central Italy. The isolates from positive coypus (29.6%) were identified as Microsporum gypseum (14.8%), Trichophyton terrestre (9.8%), Alternaria sp. (3.7%), Trichophyton mentagrophytes (2.5%), Cladosporium sp. (1.8%), Scopulariopsis sp. (1.2%), and Chrysosporium keratinophilum (0.6%), whereas the isolates from positive rats (46.7%) were identified as M. gypseum (28.1%), T. mentagrophytes (12.5%), Chrysosporium tropicum and T. terrestre (3.1% each), and Chrysosporium inops (1.6%). Statistically, brown rats were more likely to harbor fungal agents (P < 0.05) on their coat than coypus, especially T. mentagrophytes (P < 0.01) and M. gypseum (P < 0.05). No positive animal showed dermatological lesions. The present results are the first providing basic information on the coat’s mycoflora of a wild coypu population. It is concluded that the coypu, an allochthonous rodent in Italy, can play a role as natural animal reservoir of dermatophytes and as carrier of keratinophilic and saprophytic fungi within its new habitat, though to a lesser extent than indigenous rats. Therefore, people who are exposed to the risk of contact with the coat of rats and coypus should take all the cautions needed to protect themselves from mycotic agents potentially transmissible to humans.     

Effects of Nigella sativa L. and Urtica dioica L. on selected mineral status and hematological values in CCl4-treated rats

This study was designed to investigate the effects of Nigella sativa L. (NS), known as black seed, or/and Urtica dioica L. (UD), known as stinging nettle root, treatments on serum Na, K, Cl, and Ca levels and some hematological values of CCl₄-treated rats. Sixty healthy male Sprague-Dawley rats, weighing 250–300 g, were randomly allotted into 1 of 4 experimental groups: A (CCl₄-only treated), B (CCl₄+UD treated), C (CCl₄+NS treated), and D (CCl₄+UD+NS treated), each containing 15 animals. All groups received CCl₄ (0.8 mL/kg of body weight, subcutaneously, twice a week for 90 d starting d 1). In addition, B, C, and D groups also received the daily ip injection of 0.2 mL/kg NS and/or 2 mL/kg UD oils for 45 d starting d 46. Group A, on the other hand, received only 2 mL/kg normal saline solution for 45 d starting d 46. Blood samples for the biochemical analysis were taken by cardiac puncture from five randomly chosen rats in each treatment group at the beginning, d 45, and d 90 of the experiment. The CCl₄ treatment for 45 d significantly (p<0.05) increased the serum K and Ca and decreased (p<0.05) the red blood cell count (RBC), white blood cell count (WBC), packed cell volume (PCV), and Hb levels without changing (p>0.05) the serum Na and Cl levels. NS or UD treatments (alone or combination) for 45 d starting d 46 significantly (p<0.05) decreased the elevated serum K and Ca levels and also increased (p<0.05) the reduced RBC, WBC, PCV, and Hb levels. It is concluded that NS and/or UD treatments might ameliorate the CCl₄-induced disturbances of anemia, some minerals, and body’s defense mechanism in CCl₄-treated rats.     

Effects of α-tocopherol on serum trace and major elements in rats with bleomycin-induced pulmonary fibrosis

The study was undertaken to investigate the influence of α-tocopherol on zinc, copper, iron, calcium, magnesium, and potassium concentrations in serum of rats with bleomycin-induced pulmonary fibrosis. Fourteen Wistar albino rats were randomly divided into two groups of seven animals each. The first group was treated intratracheally with bleomycin hydrochloride (BM group); the second group was also instilled with BM but received injections of α-tocopherol twice a week (BM+E group). The third group was treated in the same manner with saline solution only, acting as controls (C). The zinc concentrations of the BM and BM+E groups were significantly decreased compared to the controls (p<0.05). The iron concentration of the controls was significantly higher than the other two groups. The magnesium concentration in the controls and the BM+E group was significantly higher than that of the BM group. The serum copper, calcium, and potassium concentrations were not found to be statistically different among the three groups. Distinct histopathologic changes were found in the BM group compared to the untreated rats. Less severe fibrotic lesions were also observed in the BM+E group. The results of this study show that lungs of rats treated with bleomycin were seriously damaged and that vitamin E seemed to counteract some of the damage, as indicated by differences in the serum concentrations of major elements.     

Serum and hair levels of zinc, selenium, iron, and copper in children with iron-deficiency anemia

In the present study, the serum and hair levels of zinc, selenium, and copper were determined in children with iron-deficiency anemia (IDA). A total of 52 anemic children aged 1–4 yr constituted the study group. Fortysix healthy children acted as controls. The copper and zinc levels were measured with an atomic absorption spectrophometer. Serum and hair selenium was determined by a spectroflourometric method. The serum zinc and selenium concentrations in the IDA group were found to be significantly lower and serum copper significantly higher than those in the controls (p<0.05). Lower iron, zinc, and selenium concentrations (p<0.001) but not copper were found in hair (p>0.05).     

金边红苞凤梨叶片的超微观察和AbGLK1的克隆与表达分析

为了解Golden2-like (GLK)转录因子在金边红苞凤梨(Ananas comosus var. bracteatus ‘Chiyan’)绿白嵌合叶片形成中的作用,采用RT-PCR技术克隆得到了AbGLK1基因, 其开放阅读框全长1 371 bp,编码456个氨基酸,含有1个GARP-DNA结合域和1个C末端结构域GCT box (GOLDEN2 C-terminal box),属于GLK转录因子家族,在酵母中具有转录因子的转录激活活性。烟草亚细胞定位表明AbGLK1蛋白定位在细胞核。RT-qPCR分析表明,AbGLK1基因在金边红苞凤梨的根、茎、叶中均有表达,但具有组织器官差异性,在叶片中的表达量显著高于根和茎(P < 0.05)。AbGLK1基因在叶片边缘白化组织中的表达量显著低于绿色组织,约为绿色组织的1/3 (P < 0.05)。叶片白化组织叶绿体内膜系统模糊,无类囊体存在,含有大量囊状小泡,质体小球数量多且体积较大。因此,推测AbGLK1基因可能参与了金边红苞凤梨中的叶绿体发育,其下调表达可能导致叶片白化组织中叶绿体发育不成熟。     

The Effects of Zinc Treatment on the Blood–Brain Barrier Permeability and Brain Element Levels During Convulsions

We evaluated the effect of zinc treatment on the blood–brain barrier (BBB) permeability and the levels of zinc (Zn), natrium (Na), magnesium (Mg), and copper (Cu) in the brain tissue during epileptic seizures. The Wistar albino rats were divided into four groups, each as follows: (1) control group, (2) pentylenetetrazole (PTZ) group: rats treated with PTZ to induce seizures, (3) Zn group: rats treated with ZnCl₂ added to drinking water for 2 months, and (4) Zn?+?PTZ group. The brains were divided into left, right hemispheres, and cerebellum?+?brain stem regions. Evans blue was used as BBB tracer. Element concentrations were analyzed by inductively coupled plasma optical emission spectroscopy. The BBB permeability has been found to be increased in all experimental groups (p?<?0.05). Zn concentrations in all brain regions in Zn-supplemented groups (p?<?0.05) showed an increase. BBB permeability and Zn level in cerebellum?+?brain stem region were significantly high compared to cerebral hemispheres (p?<?0.05). In all experimental groups, Cu concentration decreased, whereas Na concentrations showed an increase (p?<?0.05). Mg content in all the brain regions decreased in the Zn group and Zn?+?PTZ groups compared to other groups (p?<?0.001). We also found that all elements’ levels showed hemispheric differences in all groups. During convulsions, Zn treatment did not show any protective effect on BBB permeability. Chronic Zn treatment decreased Mg and Cu concentration and increased Na levels in the brain tissue. Our results indicated that Zn treatment showed proconvulsant activity and increased BBB permeability, possibly changing prooxidant/antioxidant balance and neuronal excitability during seizures.     

Microelements in seminal plasma of infertile men infected with Ureaplasma urealyticum

The purpose of this study was to assess the association among male infertility, infection of Ureaplasma urealyticum (Uu), and microelements in seminal fluid. Semen analysis and cultivation of Uu were carried out on 160 samples of seminal fluid. The concentrations of microelements, such as arsenic (As), molybdenum (Mo), magnesium (Mg), lead (Pb), copper (Cu), cadmium (Cd), and zinc (Zn) in the samples were measured by an inductively coupled plasma quantometer (ICP). The ratios Cu/Zn and Cd/Zn in the poor spermatic quality group were obviously higher than those in seminal plasma of the group with normal spermatic quality (p<0.01 and p<0.05, respectively), whereas the concentrations of As, Mg, Mo, and Pb showed no difference in the two groups. The ratios Cu/Zn and Cd/Zn and the concentrations of As and Mg in seminal plasma infected with Uu were markedly higher than those not infected with Uu (p<0.05, p<0.01, p<0.05, and p<0.05, respectively), whereas the concentrations of Mo and Pb showed no statistical difference. The ratios Cu/Zn and Cd/Zn and the concentrations of As and Mg in seminal plasma of the semen with poor spermatic quality and Uu infection were obviously higher than those not infected with Uu (p<0.05), whereas the concentrations of Mo and Pb showed no statistical difference. Abnormally high ratios Cu/Zn and Cd/Zn as well as an overdose of As were found to be predisposed to Uu infection. Uu infection resulted in an increase of the ratios Cu/Zn and Cd/Zn and the concentrations of As and Mg in seminal fluid, which therefore caused spermatic quality decline.     

Diurnal changes in gas exchange and chlorophyll fluorescence parameters of <Emphasis Type="Italic">Fritillaria cirrhosa</Emphasis> and <Emphasis Type="Italic">F. delavayi</Emphasis> under field conditions

To determine what factors limit the growth of wild Fritillaria cirrhosa and Fritillaria delavayi in field conditions, we investigated diurnal changes of the net photosynthetic rate (P _N) and the correlation between P _N and various environmental factors. Parameters of chlorophyll (Chl) fluorescence were evaluated to test whether ecological fragility caused the extinction of wild F. cirrhosa and F. delavayi. Our study reveals for the first time that F. cirrhosa and F. delavayi did not encounter significant stress under field conditions. A small reduction in maximum photochemical efficiency was observed under high irradiance. The maximum P _N of F. cirrhosa was 30 % higher than F. delavayi (p<0.05), and a similar difference was observed for apparent quantum yield (27.3 %, p<0.01). F. delavayi was better adapted to a wide range of irradiances and high environmental temperature. Correlation between P _N and environmental factors (without considering the effects of interactions among environmental factors on P _N) using leaves of F. cirrhosa revealed that the three primary influencing factors were air pressure (p<0.01), relative humidity (p<0.01), and soil temperature (p<0.05). In F. delavayi, the influencing factors were relative humidity (p<0.01), soil temperature (p<0.05), CO₂ concentration (p<0.05), and air pressure (p<0.05). Path analysis (considering effects among environmental factors on P _N) showed that air temperature (negative correlation), photosynthetic photon flux density (PPFD) and relative humidity were the three primary limiting factors influencing the growth of F. cirrhosa. For this species, relative humidity reacted indirectly with air pressure, which was reported singularly in other species. Limiting growth factors for F. delavayi were PPFD, air pressure (negative correlation), soil temperature (negative correlation) and air temperature (negative correlation).