Biomedical subjects

D J Price

Publications and source records attributed to D J Price.

At least 109 records · Page 6Linked to original sources

PubMed1988

Development of spatial and temporal selectivity in the suprasylvian visual cortex of the cat.

We have studied the development of the spatial and temporal properties of neurons in the medial bank of the suprasylvian visual cortex (PMLS) in kittens aged between 9 d and 8 weeks. Quantitative measurements were made of the responses to drifting high-contrast gratings of optimum orientation and direction of motion, but varying in spatial and temporal frequency. The spatial resolution ("acuity") of cells increased rapidly and was fully mature (over 2 cycles/deg for the best cells) at 3 weeks of age. The optimum spatial frequency also tended to improve and reached adult values (around 0.5 cycles/deg for the best cells) at about the end of the third week. In younger kittens, the spatial resolution of neurons was not obviously correlated with the eccentricity of their receptive fields, but in older animals acuity was clearly elevated for receptive fields in the central visual field. The proportion of "low-pass" cells (showing no obvious attenuation of response for gratings of low spatial frequency) decreased with age and simultaneously there was a slight increase in the mean spatial bandwidth of "bandpass" cells. Responses to drifting sinusoidal gratings were generally dominated by an unmodulated elevation of discharge at all ages. In tests with stationary, contrast-modulated gratings presented at different spatial positions, cells in the youngest kittens behaved nonlinearly and showed mainly an unmodulated increase in discharge, whereas in older kittens, as in adult cats, most neurons responded to contrast-modulated gratings with a small, phase-dependent response at the temporal frequency of modulation and a larger component at twice the fundamental frequency. None of the cells recorded at any age had a true "null position." As in adult PMLS, the widths of receptive fields in kittens were, on average, about twice the size of the preferred spatial period (4 times the preferred bar width). At all ages, therefore, neurons in PMLS resembled striate complex cells with respect to the nonlinearity of their responses and the spatial structure of their receptive fields. The preferred temporal frequency and high-temporal-frequency cutoff also improved, on average, during the first 3 weeks of life, and the range of temporal frequencies over which cells responded continued to increase until at least 8 weeks. Although the low-spatial-frequency inhibition that creates spatial bandpass characteristics probably depends on cortical mechanisms, the postnatal development of both temporal and spatial resolution might well be limited by maturation at the level of the retina.

Animals↗

PubMed1987

Recombinant fragment of protein kinase inhibitor blocks cyclic AMP-dependent gene transcription.

Transcriptional regulation by cyclic adenosine monophosphate (cAMP) in mammalian cells could be mediated by a phosphoprotein substrate of the cAMP-dependent protein kinase or, as in prokaryotes, by a cAMP-binding protein. Two synthetic genes that code for an active fragment of the protein inhibitor of this kinase and a mutant inactive fragment were constructed and used to distinguish these alternatives. Transient expression of the active peptide product specifically inhibited the cAMP-stimulated expression of a cotransfected reporter gene by more than 90 percent, whereas the expression of the inactive peptide did not alter cAMP-stimulated gene expression. The results indicate that an active kinase catalytic subunit is a necessary intermediate in the cAMP stimulation of gene transcription.

Acetyltransferases↗

PubMed1987

Spatial properties of neurones in the lateral geniculate nucleus of the pigmented ferret.

We used quantitative electrophysiological techniques to study the spatial properties of single units recorded extracellularly in the lateral geniculate and perigeniculate nuclei of the adult pigmented ferret. All neurones examined had approximately circular receptive fields, whose central regions gave responses antagonistic to those elicited from the surrounds. We presented sinusoidally modulated grating patterns, either drifting or counterphased, to obtain spatial frequency tuning curves, contrast sensitivity functions and to assess linearity or non-linearity of each neurone's response. In the ferret, as in other species, two types of lateral geniculate neurone could be distinguished, and we have termed these X-cells and Y-cells; both groups responded briskly to visual stimulation but X-cells gave sustained and linear responses whereas Y-cells responded transiently and non-linearly. Perigeniculate cells gave linear responses. For neurones in the lateral geniculate and perigeniculate nuclei, both the limit of spatial resolution ('acuity') and optimum spatial frequency were inversely related to receptive field eccentricity and the diameter of the receptive field centre. We recorded geniculate neurones in the ferret with acuities up to 3 cycles deg-1 and contrast sensitivities up to 114, values that are lower than those found previously for many geniculate cells in the cat.

Animals↗

PubMed1987

The organization and post-natal development of area 18 of the cat's visual cortex.

1. We made extracellular recordings from 1176 single units in area 18 of adult cats and kittens aged between 7 days and 10 weeks, and from 137 single units in area 17 in kittens aged between 12 days and 10 weeks. 2. All cells examined in area 18 of adult cats were visually responsive, 84% being orientation selective, 9% orientation biased and 7% non-oriented. Orientation columns and ocular dominance columns were identified. There was an over-all bias towards horizontal and vertical in the distribution of preferred orientations in the rostral part of area 18, where we were recording. 3. In area 18 of 7-day-old, visually inexperienced kittens the majority of cells (60%) were visually unresponsive; the remainder were either non-oriented (25%) or orientation biased (15%), and no orientation-selective units were found. Nevertheless there seemed to be a rudimentary columnar system, even in the youngest animals, in that orientation-biased cells tended to occur in clusters with neighboring neurones having similar orientation preferences. In normal animals of 3 weeks and younger we found that the distribution of preferred orientations of a sample of neurones in area 18 with receptive fields scattered over much of the left lower quadrant of the visual hemifield was biased to oblique orientations. 4. As in adult cats, most cells in area 18 in young kittens were binocularly driven, and periodic alternation of dominance along oblique penetrations, characteristic of ocular dominance columns, was sometimes seen, even at the earliest ages. 5. Many of the developmental changes that we observed in area 18 occurred during the first 4 post-natal weeks. Orientation selectivity, orientation tuning, directionality and responsiveness of neurones matured rapidly over this period. The proportions of simple and complex cells were similar in kittens aged 4 weeks or more to those in adult cats, whereas prior to this most neurones that displayed an orientation preference appeared to be immature simple cells. 6. A laminar analysis revealed that very few units in the superficial layers (I, II and III) in area 18 are visually responsive in kittens during their first and second weeks, but orientation selectivity rapidly develops during the third week. By contrast, even in very young, visually inexperienced kittens, the majority of neurones found in deeper laminae (IV, V and VI) are visually responsive and a few of them already show an orientation preference; however, the subsequent appearance of larger proportions of orientation-selective cells in these lower layers is a more prolonged process than in upper laminae.(ABSTRACT TRUNCATED AT 400 WORDS)

Action Potentials↗

PubMed1987

Effects of dark-rearing on the development of area 18 of the cat's visual cortex.

1. We recorded extracellularly from 420 single units in area 18 in visually inexperienced kittens aged 7 days and dark-reared kittens aged between 3 and 12 weeks and from 60 single units in area 17 in dark-reared kittens aged 5 and 11 weeks. 2. Visual deprivation generally depressed the maturation of area 18, although some features were affected more than others and certain developmental improvements still occurred. The percentage of visually responsive units in area 18 increased from 40% in 7-day-old kittens to about 75% in dark-reared animals 10-12 weeks. At each age a proportion of cells was orientation biased (between 15 and 45%) and these neurones appeared to be arranged in a crude columnar fashion. However, dark-rearing, from birth, prevented the development of a significant proportion of orientation-selective cells in area 18; no more than 5% of neurones were orientation-selective at any age. We found no major bias in the over-all distribution of preferred orientations of cells in area 18 in dark-reared kittens. 3. Simple cells, which are found in area 18 even in very young, visually inexperienced kittens, persisted after dark-rearing, although most retained immature properties. Relatively few complex cells were found in area 18 in visually deprived animals. 4. The majority of neurones in area 18 of dark-reared kittens were binocularly driven, many equally well by either eye; evidence for regional variation in ocular dominance (indicative of a columnar pattern) was found in these deprived animals. 5. A laminar analysis in area 18 showed that percentages of non-oriented and orientation-biased cells changed little, if at all, in lower laminae (IV, V, and VI) but increased substantially in upper layers (above layer IV) in the absence of visual stimulation, over the first 12 post-natal weeks. 6. A comparison of the effects of dark-rearing on areas 17 and 18 indicates that the normal development of visual responsiveness and specific receptive field properties is suppressed in both areas during the first 12 post-natal weeks. It is possible that area 17 has a greater degree of orientation selectivity than area 18 in young visually deprived kittens and this may reflect a difference in the type of afferent inputs.

Action Potentials↗

PubMed1986

Purification, subunit composition and regulatory properties of the ATP X Mg2+-dependent form of type I phosphoprotein phosphatase from bovine heart.

The ATP X Mg2+-dependent phosphoprotein phosphatase has been purified from bovine heart to near-homogeneity. It is a heterodimer (75 kDa) consisting of a catalytic (C) subunit (40 kDa) and a regulatory (R) subunit (35 kDa). The R subunit, which is identical to inhibitor-2, is transiently phosphorylated during activation of the enzyme catalyzed by phosphatase-1 kinase (FA). Maximal activation requires preincubation of the phosphatase with FA and ATP X Mg2+. However, relatively low yet definitively demonstrable basal activity can be expressed by Mg2+ alone (ranging from 3% to 10% of the FA X ATP X Mg activity, depending on the degree of endogenous proteolytic damage of the phosphatase during purification), but not by either FA or ATP alone. Limited trypsinization results in a rapid and total degradation of the R subunit and partial degradation of the 40-kDa C subunit to active proteins of 35-38 kDa. The resulting 'nicked' C subunit of 35-38 kDa is no longer dependent on FA for activation and can be fully activated by Mg2+ (or Mn2+) alone. Endogenous proteolytic damage of the R subunit also results in an increase of activity that can be expressed by M2+ alone with a concomitant decrease of the FA-dependent activation. Although Mn2+ is slightly more effective than Mg2+ in expressing the holoenzyme basal activity, the activation by Mn2+ is only about 60% of that of Mg2+ when FA and ATP are also present. In the activation by adenosine 5'-[gamma-thio]triphosphate (ATP[gamma S]), Co2+ is the most effective cofactor. The activation by ATP[gamma S] X Co2+ is more than 50% of that by ATP X Mg2+. The present studies indicate that Mg2+ is the natural divalent cation for the FA-catalyzed activation in which Mg2+ plays two distinctly different roles: it forms Mg2+ X ATP which serves as a substrate for the kinase; it acts as an essential cofactor for the catalytic function of the phosphatase. The discrepancies between the results obtained by this and other laboratories with respect to the effectiveness of Mg2+ and ATP[gamma S] in the activation of the phosphatase are discussed.

Adenosine Triphosphate↗

PubMed1986

Is diagnostic severity grading for head injuries possible?

The classification of head injured patients is more difficult than that for most other disease processes. The quantum of data to be embedded into each patient's grading code depends on the purpose to which that grading is used. If the information is merely required for broad epidemiological surveys, it may be confined to a double rubric which represents the most significant diagnostic component and an arbitrary index of associated severity. For this purpose, diagnostic severity grading is possible provided the task is delegated to experienced members of the neurosurgical team. If the grading is to be used in attempts to compare one patient group with another or for predictions of complications or outcome, a more detailed data-set is required. This may be accomplished with the use of multiple ICD diagnostic codes but assignations of severity to each diagnostic component requires very subjective judgement. Such an approach is unlikely to be successful and the only alternative is to define a data-set of "pure" information which includes all the relevant clinical, radiological, and operative findings without resorting to artificial data compression by using potentially misinterpretable deduced codes.

Craniocerebral Trauma↗

PubMed1986

Factors restricting the use of coma scales.

The Glasgow Coma Scale has been well established as the ideal scale for identifying specific levels of consciousness. It is widely used to provide a consistent entry criterion for series of head injuries under study, to create arbitrary thresholds for management decisions and as an important component of the data-set for comparative studies of patients in different centres with specified treatment regimes. Its international reputation for application to these 3 functions is well deserved but the dangers of summing the subscores have been rightly emphasized by the designers. Any further improvements may only cause confusion and it will undoubtedly continue as the recognized standard for many years. Unfortunately, this scale is very inadequate for monitoring head injured patients at risk of deterioration as it is insufficiently sensitive. The prompt recognition of the first signs of deteriorating consciousness is of paramount importance. A more sensitive scale encompassing more aspects of the response of the patient to the environment is required. For this purpose of trend detection, subscore summation is acceptable and nurses find a single graph easier to interpret.

Coma↗

PubMed1986

Ferritin and in vivo beryllium toxicity.

Beryllium (Be+2), a divalent metal ion, is toxic to both man and animal. Although the molecular basis for its toxicity is unknown, it is well established that micromolar concentrations of beryllium specifically inhibit certain enzymes. Previous in vitro studies have shown that the presence of ferritin, an iron-storage protein, reactivated these enzymes by sequestering beryllium (Price and Joshi, 1984). In the present study we demonstrate in vivo that beryllium and zinc are bound by ferritin in greater amounts than Pb+2, Cu+2, and Cd+2. Beryllium did not induce the synthesis of metallothionein. In animals pretreated with an iron salt (ferric ammonium citrate, 40 mg/kg body wt), liver ferritin was elevated approximately five times and the toxicity of intravenously injected beryllium was significantly attenuated. Excretion and deposition studies suggested that iron salt treatment resulted in a reduction of liver beryllium. Thus the protection against beryllium toxicity by ferric ammonium citrate may be due to increased production of ferritin which binds beryllium and its subsequent elimination in the feces.

Animals↗

PubMed1986

The postnatal development of clustered intrinsic connections in area 18 of the visual cortex in kittens.

Retrogradely transported neuronal markers were injected into area 18 of the visual cortex in normal kittens of various ages and in animals that had been binocularly deprived of patterned visual stimulation by eyelid suture. In normal kittens aged 20 days or more, distinct clusters of retrogradely labelled cells were identified in area 18 surrounding the injection sites; these cells lay mainly in cortical layers II, III, and the upper part of IV, but with some in layers V and VI. In kittens younger than 10 days, labelled cells were observed around injection sites, although they were not organized into clusters. The results suggest that the typical clustered pattern of neurones forming intrinsic connections in area 18 emerges during the second week postnatally from an immature non-patchy distribution. Binocular deprivation did not prevent the appearance of these patches of cells.

Age Factors↗

PubMed1986

Autoregulation of iodide transport in the rabbit: absence of autoregulation in fetal tissue and comparison of maternal and fetal thyroid iodination products.

Maternal and fetal rabbit thyroid glands were compared as to their ability to respond to excess iodide in vitro with a reduction in subsequent iodide transport activity. Preincubation of maternal thyroid tissue slices for 2 h with excess iodide (30 microM) resulted in a 31% reduction in the subsequently measured thyroid-medium radioiodide concentration ratio. In contrast, similar iodide pretreatment had no significant effect on fetal iodide transport. In all other respects, fetal iodide transport, although it was 10 times higher, did not differ significantly from maternal transport activity. Combined radiolabeled maternal (125I) and fetal (131I) rabbit thyroid tissue was eluted on Sephadex G-25 columns. Fractions were analyzed for both 125I and 131I activity, and the maternal to fetal ratios (125I/131I) were determined for each fraction. The majority of iodoproteins eluted with the void volume, and the 125I/131I ratio was constant in these fractions. Thereafter, two peaks of elevated 125I/131I activity could be observed. Peak A eluted below lysozyme (Mr = 14,300) and above insulin (Mr = 6,000), with an apparent mol wt of 8,000 to 10,000. A second peak, peak B, eluted from the column at a site similar to that of MIT or a protein of Mr of 2,000. Ascending paper chromatography of this latter peak of 125I/131I activity and MIT was carried out in two solvent systems. In both systems, peak B comigrated with MIT. These findings suggest that the failure of fetal thyroid tissue to exhibit autoregulation may be associated with the reduced iodination of a compound with an approximate Mr of 8,000 to 10,000. The role of this substance in iodide transport remains to be identified. The reason for the apparent increase in the labeling of MIT observed in maternal vs. fetal tissue is unknown.

Animals↗

PubMed1986

Autoregulation of thyroid iodide transport: evidence for the mediation of protein synthesis in iodide-induced suppression of iodide transport.

The role of protein synthesis in iodide-induced suppression of subsequent iodide transport (iodide autoregulation) was studied in cat thyroid slices. Thyroid slices were pretreated for 60-120 min in the presence or absence of either excess (30 microM) sodium iodide, inhibitors of protein synthesis, or both. Tissue was then washed in the presence of 2 mM methimazole to prevent subsequent iodination reaction and remove excess iodide. Iodide transport activity was finally evaluated by measurement of the ratio of tissue to medium iodide concentrations in 90-min incubations. Addition of 0.1 mM cycloheximide during the preexposure of thyroid tissue to excess iodide had no effect on either control levels of iodide transport or iodide-induced autoregulation. However, if thyroid tissue was treated with cycloheximide alone for 1 h before preexposure to excess iodide, there was a significant reduction in the degree of iodide-induced induced autoregulation. Similar results were obtained with pretreatment of the tissue with 0.5 mM puromycin and 1 microgram/ml emetine. These findings suggest that protein synthesis is involved in the mechanism of thyroid autoregulation of iodide transport. Cycloheximide had no effect on the ability of excess iodide to reduce TSH-stimulated cAMP formation. Two-dimensional gel electrophoresis-isoelectric focusing and Sephadex G-25 column chromatography employing dual-isotope comparison of iodoprotein labeling of control and cycloheximide-treated tissue suggest that the ability of cycloheximide to suppress iodide-induced autoregulation is associated with the reduced iodination of an 8- to 10-kilodalton soluble component of the thyroid gland.

Animals↗

PubMed1985

Projections from visual cortical area 19, the posterior medial lateral suprasylvian area and the lateral posterior-pulvinar complex of the thalamus to areas 17 and 18 in young kittens.

Retrogradely transported horseradish peroxidase (HRP) or HRP conjugated to wheat germ agglutinin was used to demonstrate projections from area 19, the posterior medial lateral suprasylvian area (PMLS) and the lateral posterior-pulvinar complex (LP-PC) of the thalamus to areas 17 and 18 of the visual cortex in young kittens. Areas 17 and 18 in kittens, as in adult cats, receive association fibres from cells lying mainly in deep cortical laminae in area 19 and PMLS, and projections from the LP-PC of the thalamus.

Animals↗

PubMed1985

On the mechanism of regulation of type I phosphoprotein phosphatase from bovine heart. Regulation by a novel intracyclic activation-deactivation mechanism via transient phosphorylation of the regulatory subunit by phosphatase-1 kinase (FA).

Adenosine 5'-(gamma-thio)triphosphate (ATP gamma S) can substitute for ATP in the activation of the ATP X Mg2+-dependent form of bovine heart type I protein phosphatase (Mr = 75,000) catalyzed by phosphatase-1 kinase (FA). ATP gamma S activates the enzyme to a lower level than ATP, but it phosphorylates the regulatory (R)-subunit to a much higher extent. An [35S]phosphatase-1 [( 35S]E-P) has been isolated, identified, and shown to be a key intermediate in the activation reaction. Treatment of [35S]E-P with dimethyl suberimidate results in cross-linking of the Mr = 34,000 [35S]R-subunit with the Mr = 40,000 catalytic (C)-subunit to form a Mr = 75,000 species, indicating that phosphorylation is not accompanied by dissociation of the holoenzyme. The catalytically active form (Ea) is not the phosphorylated enzyme intermediate. Instead, Ea is directly produced from the intermediate by a Mg2+-dependent, intramolecular autodephosphorylation reaction. The isolated Ea derived from [35S]E-P or from ATP-activated phosphatase-1 has the same half-life (23 min at 30 degrees C). It spontaneously deactivates, via an intramolecular process, to a resting state (Er) which can be fully reactivated by FA X ATP X Mg2+. The deactivation of Ea can be accelerated by chelators, PPi greater than ATP X Mg2+ blocks the PPi effect. Limited trypsinization selectively digests the R-subunit and the resulting C-subunit is Mg2+-dependent. Based on the present data, a novel intracyclic activation-deactivation mechanism via transient phosphorylation of the R-subunit is proposed for regulation of phosphatase-1. (formula; see text).

Adenosine Triphosphate↗

PubMed1985

Activation of bovine heart ATP-MG2+-dependent phosphoprotein phosphatase: isolation of a phosphoenzyme intermediate and its conversion to the active form via a Mg2+-dependent autodephosphorylation reaction.

The ATP-Mg2+-dependent protein phosphatase, a holoenzyme form of type I protein phosphatase (phosphatase-1) requires the action of phosphatase-1 kinase (FA) for activation. The enzyme (75 kDa) purified from bovine heart consists of a catalytic (C) and a regulatory (R) subunit of 40 kDa and 34 kDa, respectively, and activation is associated with phosphorylation of the R-sub-unit. A procedure has been developed for isolation of [32P]phosphatase-1 ( [32P]E-P) in non-denatured form. In the absence of divalent cation, [32P]E-P is catalytically inactive and the phosphorylation is stable. Addition of Mg2+ triggers autodephosphorylation of [32P]E-P with concomitant generation of phosphorylase phosphatase activity. The autodephosphorylation/activation process is dependent on Mg2+ concentration. The KA value for Mg2+ is 0.6 mM. The phosphorylase phosphatase activity generated from the release of 1 mol. 32P is 1.1 X 10(12) units which is equivalent to 15,000 units per mg enzyme protein. The present findings provide direct evidence that the phosphorylated phosphatase-1 is not the active form (Ea). Instead, Ea is directly produced from the intermediate by a Mg2+-dependent autodephosphorylation reaction.

Adenosine Triphosphate↗

PubMed1985

Patterns of cytochrome oxidase activity in areas 17, 18 and 19 of the visual cortex of cats and kittens.

The laminar pattern of cytochrome oxidase activity was studied in visual cortical areas 17, 18 and 19 in adult cats and kittens, following electrophysiological determination of the boundaries of these areas in all but the youngest animals. The patterns of cytochrome oxidase staining and the cytoarchitectonic appearances of areas 17, 18 and 19 were compared. At all ages activity was especially high in the region of layers IV and VI in areas 17 and 18, and was low in all laminae in area 19. The results suggest that the degree of cytochrome oxidase activity in these regions of the visual cortex may be related to the strength and type of projection that they receive from the lateral geniculate nucleus. The cytochrome oxidase technique is a useful means of defining the 18/19 border, and may help locate the boundary between areas 17 and 18, in both adult cats and kittens.

Age Factors↗

PubMed1985

The postnatal development of the association projection from visual cortical area 17 to area 18 in the cat.

The postnatal development of the association projection from area 17 to area 18 was studied in normal and binocularly deprived kittens between 1 and 28 days of age, using retrograde transport of horseradish peroxidase conjugated with wheat germ agglutinin. The positions of injection sites in the visual cortex, defined in relation to the borders of visual areas 17, 18, and 19 located in Nissl- and cytochrome oxidase-stained sections, were confirmed by observing the patterns of labeling of cells in the lateral geniculate nucleus. The association projection is present and is arranged at least roughly topographically from birth onward; at all ages it arises from cells in both the superficial layers (II, III, and the upper part of IV) and the deep layers (V and VI). In older kittens (20 days or more), however, the origin of the pathway is principally from the upper layers, as in adult cats, whereas in younger animals the projection arises roughly equally from cells in superficial and deep laminae. Initially, the association neurons in area 17 are distributed uniformly along each lamina. Periodic clustering of labeled cells in the upper layers can just be discerned at 10 days, and this patchiness has reached its adult clarity by 20 days, at which stage the projection from the lower layers is greatly diminished. Binocular deprivation until the age of 28 days did not prevent these developmental changes in the projection. Various controls established that the patterns of labeling seen in this study were not due to direct spread of tracer into area 17, to uptake of tracers by fibers-of-passage, or to transcellular transport via the thalamus.

Animals↗

PubMed1984

Ferritin: protection of enzymatic activity against the inhibition by divalent metal ions in vitro.

Ferritin binds a large quantity of Be2+ (Price D.J. and Joshi, J.G. J. Biol. Chem. 258 (1983) 10873) as well as other divalent metal ions. Therefore the ability of this protein to protect enzymes against or reverse the inhibition by metal ions was studied. Evidence presented here shows that the inhibition by Be2+ of the enzymes Na+K+ATPase, alkaline phosphatase and phosphoglucomutase is reversed by ferritin. Be2+ can be transferred reversibly between phosphoglucomutase and ferritin depending upon the relative concentrations of the 2 proteins. Ferritin also reactivated phosphoglucomutase inhibited by Zn2+, Cu2+, or Cd2+. Incubation of ferritin containing Be2+ with 4-10 fold molar excess of phosphoglucomutase (with respect to Be2+) removed 90% of the Be2+ from ferritin. The rates of inactivation of phosphoglucomutase by Be2+ donated by apoferritin or ferritin were identical. Based upon these observations it is suggested that Be2+ bound to the protein shell and to the iron core are in equilibrium with each other with the equilibrium favoring ferritin-Be2+ complex.

Alkaline Phosphatase↗