Effects of dietary supplementation of nickel and nickel-zinc on femoral bone structure in rabbits

Background

Nickel (Ni) and zinc (Zn) are trace elements present at low concentrations in agroecosystems. Nickel, however, may have toxic effects on living organisms and is often considered as a contaminant. This study reports the effect of peroral administrated Ni or a combination of Ni and Zn on femoral bone structure in rabbits.

Methods

One month-old female rabbits were divided into three groups of five animals each. Group 1 rabbits were fed a granular feed mixture with addition of 35 g NiCl₂ per 100 kg of mixture for 90 days. In group 2, animals were fed a mixture containing 35 g NiCl₂ and 30 g ZnCl₂ per 100 kg of mixture. Group 3 without administration of additional Ni or Zn served as control. After the 90-day experimental period, femoral length, femoral weight and histological structure of the femur were analyzed and compared.

Results

The results did not indicate a statistically significant difference in either femoral length or weight between the two experimental groups and the control group. Also, differences in qualitative histological characteristics of the femora among rabbits from the three groups were absent, except for a fewer number of secondary osteons found in the animals of groups 1 and 2. However, values for vascular canal parameters of primary osteons were significantly lower in group 1 than in the control one. Peroral administration of a combination of Ni and Zn (group 2) led to a significant decreased size of the secondary osteons.

Conclusions

The study indicates that dietary supplementation of Ni (35 g NiCl₂ per 100 kg of feed mixture) and Ni-Zn combination (35 g NiCl₂ and 30 g ZnCl₂ per 100 kg of the mixture) affects the microstructure of compact bone tissue in young rabbits.     

Plasma and tissue vitamin E concentrations in sheep after administration of a single intraperitoneal dose of dl-alpha-tocopherol

Blood plasma and tissue Vitamin E concentrations were determined in 20 sheep following a single i.p. dose of 5 g of dl-alpha-tocopherol. In addition, five sheep were used as controls (no treatment and killed at d 0). From the 20 vitamin E-dosed sheep, 4 were slaughtered on d 3, 6, 10, 15 and 28 after dosing. There was a significant time effect in alpha-tocopherol concentrations in all tissues. In most tissues, the peak alpha-tocopherol concentration was at 3 d postdosing. Uptake varied among the different tissues examined. Three days postdosing, a large uptake of vitamin E by the liver was observed; this supports the concept that hepatic tissues are a target organ for vitamin E action. Also at 3 d uptake was pronounced in spleen and lung. Vitamin E concentrations in the other body tissues at d 3 postdosing increased considerably, but to a lesser degree than those in liver, spleen and lung. Vitamin E concentration in all tissues declined 3 d after i.p. dosing.     

Plasma pharmacokinetics of alfaxalone after a single intraperitoneal or intravenous injection of Alfaxan® in rats

Alfaxalone (3α‐hydroxy‐5α‐pregnane‐11, 20‐dione) is a neuroactive steroid with anaesthetic properties and a wide margin of safety. The pharmacokinetic properties of alfaxalone administered intravenously and intraperitoneally in rats (n = 28) were investigated. Mean t_1/2elim for 2 and 5 mg/kg i.v. was 16.2 and 17.6 min, respectively, but could not be estimated for IP dosing, due to sustained plasma levels for up to 60 min after injection. Cl_p for i.v. injection was calculated at 57.8 ± 23.6 and 54.3 ± 6.8 mL/min/kg, which were 24.5% and 23% of cardiac output, respectively. The observed C_max was 3.0 mg/L for IP administration, and 2.2 ± 0.9 and 5.2 ± 1.3 mg/L for 2 and 5 mg/kg i.v. administration, respectively. AUC_0–60 was 96.2 min·mg/L for IP dosing. The relative bioavailability for IP dosing was 26% and 28% compared to i.v. dosing. Differences in t_1/2elim and Cl_p from previous pharmacokinetic studies in rats are likely due to variations in alfaxalone formulation rather than sex differences. Alfaxan^® given IP caused sustained levels of alfaxalone, no apnoea and longer sleep times than i.v. dosing, although immobilization was not induced in 30% of rats given Alfaxan^® IP. A pharmacodynamic study of the effects of combining IP injection of Alfaxan^® with other premedication agents is worthwhile, to determine whether improved anaesthesia induction could ultimately provide an alternative anaesthetic regimen for rats.     

Intestinal immunity following a single intraperitoneal immunisation in lambs

A single intraperitoneal injection of ovalbumin in oil adjuvant in young lambs has been shown to result in the appearance in the intestinal lamina propria of antibody-containing cells, most of which contained antibody of IgA specificity. Intraperitoneal immunisation of lambs with a Salmonella typhimurium vaccine during the suckling period provided protection against postweaning challenge with live organisms. This response was shown to be associated with specific IgA antibody in intestinal secretion.     

Changes in compact bone microstructure of rats subchronically exposed to cadmium

Background

Chronic exposure to cadmium (Cd), even at low concentrations, has an adverse impact on the skeletal system. Histologically, primary and secondary osteons as basic structural elements of compact bone can also be affected by several toxicants leading to changes in bone vascularization and mechanical properties of the bone. The current study was designed to investigate the effect of subchronic peroral exposure to Cd on femoral bone structure including histomorphometry of the osteons in adult male rats.In our study, 20 one-month-old male Wistar rats were randomly divided into two experimental groups. In the first group, young males received a drinking water containing 30 mg of CdCl₂/L, for 90 days. Ten one-month-old males without Cd intoxication served as a control group. After 90 days of daily peroral exposure, body weight, femoral weight, femoral length, cortical bone thickness and histological structure of the femora were analysed.

Results

We found that subchronic peroral application of Cd had no significant effect on body weight, femoral length and cortical bone thickness in adult rats. On the other hand, femoral weight was significantly increased (P < 0.05) in Cd-intoxicated rats. These rats also displayed different microstructure in the middle part of the compact bone where vascular canals expanded into central area of substantia compacta and supplied primary and secondary osteons. Additionally, a few resorption lacunae which are connected with an early stage of osteoporosis were identified in these individuals. Histomorphometrical evaluations showed that all variables (area, perimeter, maximum and minimum diameter) of the primary osteons’ vascular canals, Haversian canals and secondary osteons were significantly decreased (P < 0.05) in the Cd group rats. This fact points to alterations in bone vascularization.

Conclusions

Subchronic peroral exposure to Cd significantly influences femoral weight and histological structure of compact bone in adult male rats. It induces an early stage of osteoporosis and causes reduced bone vascularization. Histomorphometrical changes of primary and secondary osteons allow for the conclusion that the bone mechanical properties could be weakened in the Cd group rats. The current study significantly expands the knowledge on damaging action of Cd on the bone.     

Response of plasma bone markers to a single intramuscular administration of calcitriol in dairy cows

To elucidate the effects of an exogenous calcitriol (1,25-dihydroxyvitamin D₃) on plasma bone markers, the formation item osteocalcin (OC), undercarboxylated OC (ucOC) and bone-specific alkaline phosphatase (BALP), and the resorption parameter tartrate-resistant acid phosphatase isoform 5b (TRAP5b) and hydroxyproline (HYP) were measured in conjunction with plasma calcitriol and calcium (Ca) concentrations in dairy cows receiving calcitriol or its vehicle according to a 2 × 2 crossover design. Calcitriol (0.5 μg/kg, i.m.) increased significantly its plasma level during 6 h to day 2 and plasma Ca concentration during 12 h to day 7 compared to the vehicle. Also, plasma OC and ucOC started to rise from day 3 and 1, respectively, and remained elevated until day 7. No change in plasma BALP, TRAP5b or HYP associated with calcitriol treatment was noted. These results demonstrate that exogenous calcitriol stimulates osteoblasts to biosynthesise OC, a determinant of the bone formation in cows.     

Vitamin E concentrations in blood plasma of sheep and in sheep tissues after a single intraruminal or intraperitoneal administration of DL-alpha-tocopheryl acetate

Twenty-five yearling wethers, weighing 40 to 45 kg were used in a trial designed to compare the effect of the route of administration of vitamin E upon plasma and tissue vitamin E status. Five control sheep without vitamin E administration were killed at the beginning of the trial. Of the remaining 20 sheep, 10 were given DL-alpha-tocopheryl acetate intraruminally and 10 by intraperitoneal injection. Of these, 10 wethers were killed three days after dosing (five from each treatment, IR3 and IP3) and the remaining wethers were killed eight days after dosing (IR8 and IP8). Blood samples were taken throughout the trial from sheep on the IR8 and IP8 treatments. Samples of whole adrenal gland, heart, liver, kidney, brachiocephalicus muscle, lung, pancreas and spleen were taken from all sheep at slaughter and were analysed for their vitamin E content. The blood plasma results showed that the most important index of vitamin E bioavailability, the area under the plasma concentration versus time curve, was greater in the intraperitoneally than intraruminally dosed sheep. There was a higher concentration of vitamin E in the tissues from the intraperitoneal group than the intraruminal group three days after the intraperitoneal injections. The results suggest that the greatest responses in vitamin E concentration in plasma and the tissues were recorded in sheep following intraperitoneal rather than intraruminal dosing with DL-alpha-tocopheryl acetate.     

Oral administration of Kaempferia parviflora did not disturb male reproduction in rats

To investigate the androgenic effect of Kaempferia parviflora (KP), a Thai herbal plant, adult male rats were randomized into control and KP-treatment groups. Rats were treated orally with water in the control group and with 1,000 mg/kg/day of KP in the treatment group for 45 days. Blood samples were collected on days 10, 20, 30 and 45 for measurement of the serum follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone, progesterone and corticosterone levels. The reproductive and non-reproductive organs were dissected on day 45 and weighed. Mating behavior was also observed on days 20 and 30. Body weight was measured throughout the study period. The results showed that KP induced an increase in body weight compared with the controls. There were no significant differences in the weights of either reproductive (testis, seminal vesicle plus coagulating gland, levator ani muscle plus bulbocarvernosus muscle and glans penis, except the prostate gland) or non-reproductive organs (kidney, adrenal gland and gastracnemius muscle). There were no significant differences in serum levels of either FSH or LH between the two groups. The serum testosterone and progesterone levels were insignificantly lower in the KP group during the first 30 days. The serum corticosterone levels in the KP group were lower than those in the controls throughout the study period and were significantly low on days 20 and 30. There were no significant changes in mating behavior in the rats treated with KP. Although KP affected the body weight and serum corticosterone level, it did not affect mating behavior, reproductive and non-reproductive organ weights or hormones related to the reproductive system in the adult male rats. Therefore, we conclude that the testosterone-like effect of KP did not disturb the hypothalamic-pituitary-testicular axis or male reproduction.     

Effects of intermittent and continuous administration of decoquinate on bovine coccidiosis in male calves

Male Holstein calves were each inoculated with 350,000 sporulated oocysts of Eimeria bovis. Two calves were given decoquinate (0.5 mg/kg of body weight) continuously in dry feed for 29 days, and 2 calves each were given 0.5, 1, or 1.5 mg of decoquinate/kg on an every 2nd-or 3rd-day schedule for 29 days. Calves given decoquinate continuously did not discharge oocysts but had slightly loose feces. In general, the number of oocysts discharged increased and fecal consistency decreased as the time between feeding of medicated feed increased. Calves given 0.5 or 1.5 mg of decoquinate/kg every 3rd day discharged more oocysts and had more diarrhea than did calves given 1 mg of decoquinate/kg every 3rd day. At postinoculation day 29, calves were euthanatized. At necropsy, intestinal tissues of calves given decoquinate were mostly normal. Apparently, reduced infections along with the elapsed time were sufficient to resolve most intestinal lesions caused by the coccidia. Decoquinate was most effective when fed continuously at 0.5 mg/kg. However, when fed at 1 or 1.5 mg of decoquinate/kg every 2nd day or 1.5 mg of decoquinate/kg every 3rd day, oocyst production was reduced and clinical coccidiosis was prevented.     

氟对不同日龄雄性大鼠睾丸组织中表皮生长因子及其受体表达的影响

为探讨氟对不同日龄雄性Wistar大鼠睾丸组织中表皮生长因子（EGF）及其受体（EGFR）表达的影响,选用40日龄雄性Wistar大鼠200只,随机分为2组分别饮用含150mg/L氟化钠的去离子水和去离子水,并于50,80,100,120日龄时处死大鼠,对睾丸组织中EGF及其EGFR的表达情况进行分析。结果表明,染氟组50日龄时睾丸组织间质细胞、精原细胞和生精细胞中EGF的表达量极显著下降（P〈0.01）,精子细胞和管腔脱落物中EGF的表达量降低不明显（P〉0.05）;80,100,120日龄时虽有下降趋势,但无统计学意义（P〉0.05）。而染氟组睾丸组织中EGFR的表达量在50,80,100日龄时均降低,但50,80日龄睾丸组织精子细胞和100日龄睾丸组织曲细精管管腔脱落物中EGFR的表达量极显著下降（P〈0.01）,50日龄时生精细胞中EGFR的表达量显著降低（P〈0.05）;而120日龄时睾丸组织中EGFR的表达量均增高,且管腔脱落物中极显著增高（P〈0.01）。证明氟可降低雄性Wist-ar大鼠性成熟时EGF的表达量以影响精子的生长发育,长期抑制EGF的表达使EGFR的表达增高影响生殖功能。     

Effects of physiological covariables on pharmacokinetic parameters of clomipramine in a large population of cats after a single oral administration

This study was conducted to confirm an interindividual variability in pharmacokinetic parameters of clomipramine in a large population of cats and to identify potential covariables that would explain the presence of such pharmacokinetic variability after a single dose of Clomicalm. Clomipramine hydrochloride was administered orally according to a weight-dose chart from 0.32 to 0.61 mg/kg, to 76 cats and five blood samples were then taken by direct venipuncture at 1, 3, 6, 12, and 24 h. Plasma concentrations of clomipramine and desmethylclomipramine (DCMP) were measured by LC-MS/MS. The Standard Two-Stage technique was used to assess differences and detect correlations between pharmacokinetic parameter estimates and individual covariables. A large interindividual variability in all pharmacokinetic parameters (CV% 64-124) was detected. Statistically significant gender-related differences were detected in MR and Cl/F, where female cats had a higher mean MR (0.53) and faster Cl/F (0.36 L/h.kg) than males (0.36 and 0.21 L/h.kg, respectively). No correlation could be found between clomipramine AUC0-24 h or DCMP AUC0-24 h and sedation scores. Further feline studies are required to assess these findings after multiple dosing of clomipramine and DCMP to allow clinical extrapolation.     

Effects of vinclozolin administration on sperm production and testosterone biosynthetic pathway in adult male rat

The effect of vinclozolin (VCZ), used as a fungicide and known to have anti-androgenic effects on spermatogenesis and gene expression in the male rat testis was investigated. In Experiment 1, VCZ (100 mg/kg/day) or flutamide (FM, 25 mg/kg/day) was orally administered to male Holzman rats for six days. 8 days after the last administration (D8), a drastic increase in intratesticular testosterone was detected in FM (4.2-fold over control) but not in VCZ treated animals, whereas on D36 post-administration, both groups showed similar levels. Significant decreases in daily sperm production were seen in both VCZ and FM-treated rats on D36. Semiquantitative RT-PCR analysis with testicular and pituitary mRNAs on D8 revealed that LHbeta and FSHbeta mRNAs were increased in the pituitary by VCZ, as well as by FM. Among the four testicular steroidogenic enzyme genes, cytochrome P450 side chain cleavage (P450scc) and cytochrome P450 17alpha/C(17-20) lyase (P450c17) mRNAs were significantly increased, whereas 17beta-hydroxysteroid dehydrogenase type III (17betaHSD) mRNA was not changed. A significant increase in 3beta-hydroxysteroid dehydrogenase type I (3betaHSD) and a decrease in androgen receptor (AR) mRNA were observed only in FM treated rats. Immunohistochemistry demonstrated intense staining of P450scc in the interstitial cells of VCZ-treated testis on D8. In Experiment 2, hormone levels were measured at 1, 3, 6, 12 and 24 hours after VCZ (100 mg/kg) administration to Sprague-Dawley rats. Serum LH level remained constant for the first 3 hours and started to increase at 6 hrs. In contrast, serum and intratesticular testosterone levels increased 2-fold at 1 hr and maintained the level until 24 hrs. P450c17 mRNA level was 2-fold increased at all periods, whereas no obvious changes were detected in the other steroidogenic enzyme genes. Although not statistically significant, AR mRNA level increased 2-fold, 3 hrs after VCZ administration. These results indicate that VCZ affects the pituitary in a similar manner as FM, but functions differently on testicular gene expression.     

Evaluation of intraperitoneal and intrahepatic administration of a euthanasia agent in animal shelter cats

One hundred eighty-one adult cats, with body weight greater than 1.8 kg, were obtained from animal shelters, then were administered a sodium pentobarbital-lidocaine euthanasia agent by either the intraperitoneal (IP; n = 77) or intrahepatic (IH; n = 85) route. A preliminary study (n = 19 cats) indicated that most cats gave no indication of perception of injection (responding) if restraint was minimal and injection was rapid. During IP injection, 3 of the 77 cats (4%) responded (turned the head backward or vocalized). Of the 85 cats given IH injection, 8 (9%) responded; however, no response approached the magnitude of that observed after IM injection of ketamine hydrochloride. After either injection route, cats were observed for excitement (any exaggerated activities of stage-I and -II anesthesia (eg, vocalizing, flopping, sneezing, licking, running, paddling), and after cardiac standstill, cats were necropsied to identify exact location (final site) of the injection. Of 53 initial IP injections, final site for 22 (42%) was in the peritoneal cavity (PC). Use of a sideport needle (n = 24) did not significantly increase accuracy of IP injection. The small and large intestines were penetrated by 27% (15/55) of the IP injections from the right side, and the spleen was penetrated by 32% (7/22) of the left-side injections. Intrahepatic injection was significantly (P less than 0.05) more accurate, with 70 of 85 (82%) of the final sites being the liver only, the liver/PC, or the PC only. Twenty-five percent (13/53) of IP injections resulted in excitement (all stage-I and -II anesthesia-exaggerated activities cumulative to 30 seconds).(ABSTRACT TRUNCATED AT 250 WORDS)     

铅镉联合暴露对大鼠肾脏的氧化损伤

采用饮水对大鼠进行铅(Pb)300 mg/L、镉(Cd)50 mg/L单独和联合(Pb+Cd)300 mg/L+50 mg/L染毒8周,通过检测肾脏皮质组织抗氧化指标和超微结构的变化来探讨铅镉对大鼠肾脏的毒性损伤及其机理.结果表明,Pb、Cd单独或联合染毒使肾脏皮质组织超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性和还原型谷胱甘肽(GSH)含量显著或极显著低于对照组(P<0.05或P<0.01),以铅镉联合组降低幅度最大(P<0.01);3个染毒组丙二醛(MDA)含量显著或极显著高于对照组(P<0.05或P<0.01),联合组升高幅度最大而极显著高于单独染毒组(P<0.01).超微结构发现,铅镉染毒导致线粒体肿胀、膜损伤、嵴断裂或消失,联合组损伤程度重于单独染毒组.表明氧化损伤是Pb、Cd肾脏毒性的机制之一,其联合毒性表现为协同效应.     

Structural changes in femoral bone tissue of rats after subchronic peroral exposure to selenium

Background

The role of selenium (Se) on bone microarchitecture is still poorly understood. The present study aims to investigate the macroscopic and microscopic structures of femoral bone tissue in adult male rats after subchronic peroral administration of Se.

Methods

Twenty one-month-old male Wistar rats were randomly divided into two experimental groups. In the first group (Se group) young males were exposed to 5 mg Na₂SeO₃/L in drinking water, for 90 days. Ten one-month-old males without Se administration served as a control group. At the end of the experiment, macroscopic and microscopic structures of the femurs were analysed using analytical scales, sliding instrument, and polarized light microscopy.

Results

The body weight, femoral length and cortical bone thickness were significantly decreased in Se group rats. These rats also displayed different microstructure in the middle part of the femur, both in medial and lateral views, where vascular canals expanded into the central area of the bone while, in control rats, these canals occurred only near the endosteal surfaces. Additionally, a smaller number of primary and secondary osteons was identified in Se group rats. Histomorphometric analyses revealed significant increases for area, perimeter, maximum and minimum diameters of primary osteons’ vascular canals but significant reductions for all measured variables of Haversian canals and secondary osteons.

Conclusions

Se negatively affected the macroscopic and microscopic structures of femoral bone tissue in adult male rats. The results contribute to the knowledge on damaging impact of Se on bone.     

Effects of soya milk on reproductive hormones during puberty in male Wistar rats

Puberty is considered a critical period on development that involved sexual maturation and morphological changes. Isoflavones have been described as endocrine disruptors in male rats. Therefore, the present study attempt to evaluate the effect that daily intake of low and high doses of isoflavones exert into the hormonal regulation that take place during puberty by analyzing the levels of serum and testes steroid and pituitary hormones. 108 male pre‐puberal Wistar rats (30 days old) were randomly divided into three groups; control, low and high doses of isoflavones. Experimental animals were daily dosed orally with low and high doses of a mixture of two soy isoflavones (genistein and daidzein) during 6 weeks. An EIA was performed in serum and testes homogenates for analyzing FSH, LH, P5, P4, DHEA, A4, T, DHT, SO4E1 and E2 hormone concentrations. Results revealed a decrease of an oestrogen environment in testes stimulates the secretion of FSH and LH leading to the production of androgens in the testes at the onset of puberty. Low doses of isoflavones resulted in a significant increase of testes oestrogens that consequently produced a delay on the onset of puberty; however at high doses of isoflavones the maintained oestrogenic environment in the testes prevent the stimulation of the secretion of pituitary hormones and the production of T abolishing the onset of puberty. These results clarify the hormonal mechanisms that take place on puberty and determine the effect of high and low doses of isoflavones at the onset of puberty.     

Effects of surgery and analgesic administration on spontaneous behaviour in singly housed rats

The study examined the use of behaviour in assessing post-laparotomy pain in rats given subcutaneous injections of saline (0.2 ml 100 g(-1)) or the analgesics buprenorphine (0.05 mg kg(-1)) or ketoprofen (5 mg kg(-1)). Procedural control influences (handling/movement, anaesthesia, injections) were studied in a second group. Of 150 behaviours examined, discriminant analysis classified the main treatment effects, and class mean frequencies were compared between treatments within each group. With the exception of buprenorphine treatment, control procedures reduced the frequency of active, attentive and grooming behaviour, and increased sleeping during 24 hours following each treatment. Moving animals to the theatre was the main factor responsible for these changes. Surgery also reduced active and attentive behaviour. Animals given pre-operative saline were more frequently inactive than those given ketoprofen. These effects most likely resulted from post-surgery pain, but this was not significantly diminished with the ketoprofen dose used. In all cases, buprenorphine outweighed these effects, causing a sustained increase in active, inactive and attentive behaviour, such that determination of any analgesic effects was impossible. The study underlined a role for pain assessments based on rat behaviour. Drug-related effects emphasised a need for more comprehensive assessments encompassing procedural influences, before behaviour changes that are potentially pain related may be determined accurately.     

Effects of age on the pharmacokinetics of single dose sulfamethazine after intravenous administration in cattle

Sulphonamides are still being used widely, influenced by the low cost and the efficacy against many common bacterial infections, since they present a broad spectrum of activity. The aim of this study was to determine the effect of age on the pharmacokinetic/pharmacodynamics (PK/PD) integration of intravenous sulfamethazine (60 mg/kgbw) in cattle, and the possible therapeutic outcomes. Six healthy female calves, at the age of one, three, seven and fifteen weeks were used. Normality analysis was assessed with the Shapiro-Wilk test. Non-parametric tests for paired data were used. Plasma concentrations were quantified using HPLC/uv. Differences were found between one-three-weeks-old calves and seven-fifteen-weeks-old calves, in pharmacokinetic parameters (clearance, area under the concentration-time curve and elimination half-life) and in the PK/PD integration. The ratios obtained in PK/PD integration (T>MIC, WAUC) confirm that it is necessary to apply twice the dose of sulfamethazine in ≥ 7 weeks-old cattle to reach a satisfactory dosage regimen (MIC ≥ 32 μg/mL).     

Effects of large granular lymphocyte leukemia on bone in F344 rats

Large granular lymphocyte (LGL) leukemia was induced in 40 F344 rats by inoculating them with neoplastic cells to evaluate the effect of acute leukemia on bone remodeling and calcium balance. The rats developed leukemia and splenomegaly by 9 days after inoculation. The rats had reduced body weight (day 12), food intake (days 4, 8, 12), urine production (day 12), and fecal output (day 12). Serum calcium and phosphorus and urinary excretion of calcium and phosphorus were decreased on days 8 and 12 in leukemic rats. Static bone histomorphometry of trabecular bone in lumbar vertebrae demonstrated reduced bone area, no change in the number of osteoclasts, and reduced osteoclast perimeter at day 12. Dynamic bone histomorphometry revealed reduced double labeled perimeter, mineralizing perimeter, trabecular mineral appositional rate, and bone formation rate in rats with LGL leukemia at days 9 and 12. There was no change in periosteal mineral appositional rate. Rats with leukemia and intramedullary neoplastic cells had a reduction in bone formation rate that resulted in a loss of trabecular bone.     

Effects of vitamin A deficiency on the function of pituitary-gonadal system in male rats

The effects of vitamin A deficiency on the pituitary-gonadal function were examined by measurements of serum and pituitary level of pituitary hormones and serum testosterone concentration, and by investigations of histological changes in the testis and the pituitary gland in vitamin A-deficient (VAD) and supplemented (VAS) rats. The growth of VAD rats was retarded and their body weights were decreased after 9 weeks of experiments and attained about one half of the weight of control animals at 12 weeks. In the VAD rats, serum testosterone concentrations were decreased significantly compared with those in the VAS controls. Serum and pituitary concentrations of GH were significantly lower but those of LH were slightly lower in the VAD rats than those in the controls, while the serum FSH concentration was significantly higher than that in the control rats. The seminiferous tubules in the testes of VAD rats were comprised largely of Sertoli cells and a reduced number of spermatogonia and contained fibrous formation in their lumen. In the pituitary gland, GH cells were significantly reduced in number in the VAD rats, but gonadotropic (GTH) cells were increased remarkably in size and number, showing hypertrophy and vacuolation similar to those in castration cells. The cytological changes in the pituitary gland and the increased discharge of FSH represent a secondary and compensatory change similar to that seen following castration and vitamin E deficiency.