Search

The acid phosphatase activity in the parathyroid of mice, rats, dogs and newts was observed by electron microscopy to distinguish mature secretory granules from lysosomal dense bodies.In the parenchymal cell reactive and non-reactive granules were both present. Most of the non-reactive granules were membrane-bounded, electron moderately dense to highly dense, round, homogeneous bodies with a finely particulate texture. Such granules were similar in fine structure to so-called prosecretory granules in the Golgi area and were concluded to be mature secretory granules. Some other non-reactive granules, including both vacuoles with a finely granular content and so-called multivesicular bodies, were thought to originate from secretory granules.The maximum size of these mature secretory granules was different in various animal species and reached 0.7μ in mice, rats, and newts, whereas 0.5μ in dogs.In newts, gradual transformation of secretory granules, especially tubule-containing granules, into lysosomes was indicated.

There has been no conclusive proof that oxyphil cells are capable of secreting parathyroid hormone. Likewise there has been no convincing evidence that oxyphil adenomas are associated with excess hormone production. A 70-yr-old patient presented with hypercalcemia, hypophosphatemia and subperiosteal bone resorption of her phalanges. Selective venous sampling of the neck veins showed elevated levels of parathyroid hormone in the right jugular vein as measured by radioimmunoassay. Surgical exploration of the neck revealed a parathyroid adenoma on the right side of the neck which consisted exclusively of oxyphil cells by light and electron microscopy. Electron microscopy of the tumor cells showed a striking abundance of mitochondria, numerous secretory granules, well-developed Golgi apparatus and rough surfaced endoplasmic reticulum, suggesting increased hormone secretory activity. Our findings indicate that pure oxyphil adenomas can be associated with hyperparathyroidism and that oxyphil cells are ...

The effect of magnesium depletion on serum calcium and magnesium and on the response to the infusion of parathyroid extract (PTE) was evaluated in nine adult mongrel dogs during a control period, magnesium depletion, and following magnesium repletion. Magnesium depletion was associated with a fall in serum magnesium and calcium, and both returned to normal with magnesium repletion. There was a significant direct correlation between the serum concentration of calcium and magnesium in the magnesium-deficient state. During magnesium depletion, there were significant calcemic and phosphaturic responses to PTE, but these effects were reduced; the impaired responsiveness of the skeleton and the kidney to PTE returned to normal after magnesium repletion. Serum levels of immunoreactive parathyroid hormone, measured in two animals during the control and magnesium depletion state, remained stable during magnesium depletion, despite the hypocalcemia present. These results indicate that both impaired responsiveness of the skeleton to parathyroid hormone and reduced secretion of the hormone in response to hypocalcemia exist in dogs with magnesium depletion. Each of these factors probably contributes to a reduced level of serum calcium in magnesium depletion, and they may compound each other and hence aggravate the degree of hypocalcemia.

Renal failure of 4 wk duration in rats led to parathyroid enlargement, increased bone resorption, and decreased tubular reabsorption of phosphate by the remnant kidney. The degree of hyperparathyroidism was influenced by each of the three dietary factors investigated. In the first study increasing calcium intake reduced the size of the parathyroids by increasing calcium and reducing phosphate absorption. In the second study phosphate intake was linearly related to parathyroid gland size in the uremic animals and associated with rising plasma phosphate levels. In the last study acidosis led directly to increased bone resorption but small parathyroid glands associated with elevated ionized calcium levels. Alkalosis lowered the serum ionized calcium and led to parathyroid enlargement and the expected associated findings. It was shown that parathyroid weight reflected both metabolic activity as judged by amino acid uptake, and the content of immunoassayable parathyroid hormone. In all studies gland weight was inversely related to serum ionized calcium.

Bovine parathyroid gland slices incubated in vitro have been shown to synthesize parathyroid hormone. The incorporation of several radioactive amino acids into the hormone isolated from the tissue was found to vary inversely with the concentration of calcium present in the incubation medium. The identity of the newly synthesized hormone with parathyroid hormone was established by several lines of evidence, including a demonstration of calcium-mobilizing activity in the parathyroidectomized rat. The stimulatory effect of lowered calcium concentration was directed more to incorporation of amino acid into the hormone than into the general protein of the tissue. Examination of the incubation medium indicated significant incorporation of amino acid into soluble protein, but this was unaffected by calcium concentration. The presence of hormone in the incubation medium could not be demonstrated either by attempted isolation or by assays for biological activity.

TWO hypotheses have been advanced in explanation of the parathyroid hormone control over the level of ionized calcium in the tissue fluids. One is that the hormone induces a release of calcium by a direct stimulating action on the bones (Thomson and Collip, 1932); chemical changes, as reflected by the varying concentrations of calcium and of phosphorus in the serum and in the urine, are considered secondary manifestations. According to the other hypothesis, the hormone acts primarily on the electrolyte equilibria of the body fluids in such a manner as to increase their solvent power for bone salts; bone dissolution follows as a secondary phenomenon (Albright et al., 1929; Albright and Reifenstein, 1948). In brief, the sequence of events is supposedly: (1) the hormone acts on tissue fluid phosphate rendering it more readily excretable by the kidney; (2) serum phosphate is thereby decreased resulting in tissue fluid undersaturation with respect to some equilibrium constant regulating serum calcium and phosp...

INVESTIGATIONS concerning the relationship of the parathyroid gland to the other glands of internal secretion have been limited for the most part to certain experiments concerning the effect of hypophysectomy and the effect of the administration of anterior hypophysis on the parathyroid gland. The former procedure was found to diminish or inhibit the proliferative activity of the parathyroid, whereas administration of anterior hypophysis increased it. These earlier experiments were qualitative in nature and the degree of increase or decrease in proliferative activity of the parathyroid under these experimental conditions was not accurately determined; nor was the effect of other endocrine glands than the anterior hypophysis on the activity of the parathyroids studied by more exact means. No definite experiments seem to have been made concerning the possibility that the effect of the administration of anterior pituitary substance upon the parathyroids might be mediated through one or more of the other endo...

DESPITE the refinements of modern thyroid surgery, an occasional patient still suffers chronic deprivation of parathyroid function as a result of operation. Medical management of the deficiency over a period of years may give rise to renal or ophthalmic complications. As a consequence, it would be desirable to provide an endogenous source of parathyroid secretion in certain cases by transplantation of functioning gland into the patient. In the present state of knowledge, homologous transplantation (the transfer of tissue from one person to another) has usually resulted in rejection of the transplanted tissue by the host because of the "individuality" of . . .

Bovine parathyroid gland slices were incubated in vitro in buffers containing concentrations of calcium in the range of 0.5 mm to 2.0 mm and magnesium in the range of 0.2 mm to 1.7 mm and either a 3H- or a 14C-amino acid. After incubation, radioactive parathyroid hormone was isolated from both the tissue and the incubation medium by a combination of methods including gel filtration and ion exchange chromatography. The isolation, localization, and quantification of parathyroid hormone present at various stages of purification was assisted by adding to the samples, prior to processing, small amounts of biologically synthesized, highly purified radioactive parathyroid hormone as an internal standard. The use of the internal standard to correct for losses of parathyroid hormone during processing was particularly necessary due to the finding that a large fraction of radioactive parathyroid hormone in the experimental samples could be adsorbed to the chromatographic columns employed to isolate the hormone. When the concentration of calcium was lowered, there was an increase in radioactive parathyroid hormone isolated from both the tissue and the medium. In contrast, changes in magnesium concentration had no effect on the biosynthesis of parathyroid hormone. The hormonal species obtained from tissue and the one isolated from incubation medium migrated in an identical fashion during chromatography on gels and upon electrophoresis, indicating that this species was similar to that extracted from the tissue.

RECENT reports1 2 3 4 have described patients with coexisting tumors of the parathyroid gland, pituitary gland, pancreatic islets and (in some cases) adrenal cortex. The occurrence of these multiple endocrine tumors poses fascinating questions of etiology and raises formidable problems of diagnosis and treatment. Recently, we observed a patient with recurrent bilateral familial pheochromocytomas, hyperparathyroidism with multiple parathyroid adenomas and thyroid carcinoma — a combination of findings not previously reported. Case Report An 18-year-old girl was admitted to the Mayo Clinic for the 1st time in August, 1951. Five months earlier bouts of palpitation had begun. One month later persistent tachycardia had . . .

An unusual case of the polyglandular adenoma syndrome is described. The patient was a twenty-eight year old married woman presenting with secondary amenorrhea and galactorrhea. Detailed analysis revealed that she was suffering from Cushing's syndrome due to an adrenal tumour and hyperparathyroidism. An enlarged parathyroid gland and an adrenal adenoma were removed. During adrenal surgery an asymptomatic nonbeta cell pancreatic adenoma was also removed. Results of physical, biologic and immunologic investigations of the tumour extract demonstrated the presence of huge amounts of pancreatic glucagon. The pancreatic adenoma is therefore designated a glucagonoma. Serum levels of glucagon-like immunoreactivity were slightly elevated before pancreatic surgery and within normal limits thereafter. Seven months after the patient was treated for Cushing's syndrome, when no otherwise overt hormonal imbalance existed, no pancreatic beta cell hyperresponsiveness to a glucose load could be demonstrated. The results are discussed in relation to the pathogenesis of the polyglandular adenoma syndrome.

Knowledge of parathyroid tumors is rather recent. Sandstrom suggested the hypothesis of their origin when he discovered the parathyroid gland in 1880. According to Berard and Alamartine, parathyroid tumors were for a long time difficult to distinguish from tumors of the thyroid gland, and many were diagnosed as fetal adenomas of Wolfler. Kocher, in 1899, described five cases of goiter containing glycogen and suggested that they might be parathyroid glands. In 1900, De Santi first described a parathyroid tumor in the carotid region. Some of the tumors did not cause symptoms during life and were discovered at necropsy. Small nodules were found in the usual parathyroid situation or deeply placed in the thyroid gland and encapsulated. It is known that parathyroid glands are found in various situations and that they might give rise to hyperplasia and even tumors, just as accessory thyroid glands and accessory breast tissue give rise to carcinoma.

Context: The parathyroid gland, the last major organ to be recognized in humans, is an essential endocrine gland. The hormone secreted by the parathyroid gland provides a powerful mechanism for controlling extracellular calcium and phosphate concentrations. Knowledge of location and number of parathyroid gland is essential to surgeon, endocrinologist, sonologist and pathologist for better diagnosis and management of parathyroid diseases. Study design: A descriptive type of study. Place and period of study: Department of Anatomy, Dhaka Medical College, Dhaka from January 2008 to December 2008. Materials: The present study was performed on post mortem parathyroid glands of 60 Bangladeshi people in different age groups. Total 207 parathyroid glands were taken from this 60 cadavers. The samples were collected from the unclaimed dead bodies within 24 hours after death that were under examination in the Department of Forensic Medicine of Dhaka Medical College, Dhaka. Methods: The samples were divided into three different age groups ranging from 15 to 75 years. The three groups are group A (10-30 years), group B (31-60 years) and group C (61-90 years). All samples were studied morphologically. Results: In the present study of 60 cadavers, 207 parathyroid glands were identified in relation to posterior border of thyroid lobe. And most of the superior parathyroid glands were found on the middle third of the posterior border of the thyroid lobe and most of the inferior parathyroid glands were found on the lower third of the posterior border of the thyroid lobe. In this study the highest number of parathyroid glands per person was four, found in about 63.333% of cases and lowest was one, found in 5% of cases, two parathyroid glands were found in 8.33% of cases and three parathyroid glands were found in 23.33% of cases. The average number of parathyroid glands per person was 3.45. Conclusion: The parathyroid glands vary in number and location. Key words: Location; number; parathyroid gland. DOI: 10.3329/bja.v7i2.6086 Bangladesh J. Anat. 2009; 7(2) : 73-79

The effect of various substances on parathyroid hormone (PTH) release was studied in vitro, in an attempt to determine whether adenosine 3′,5′–monophosphate (cyclic AMP) may be involved in regulating PTH release. Bovine parathyroid gland slices were incubated for 5 hr in tissue culture medium. The medium was changed each hour and analyzed for PTH concentration by radioimmunoassay. After the first 2 hr of incubation in medium with 1.5 mM calcium (Ca) concentration, the composition was changed to that of the test condition. Incubation with low Ca (0.75 mM) medium increased PTH release, and incubation with high Ca (3.0 mM) medium decreased PTH release significantly. PTH release was increased significantly by 10 mM dibutyryl cyclic AMP, 2 mM aminophylline, or 0.45 mM epinephrine. These in vitro observations a) strongly suggest that PTH release is influenced by cyclic AMP in the parathyroid cell, and b) further suggest that the known hypocalcemic stimulus of PTH release is mediated by the adenyl cyclasecyclic ...

Es wird versucht, Ursachen und Bedeutung der erstmals von Romeis (1926) beschriebenen jahreszyklischen Strukturveranderungen an den Epithelkorperchen (EK) von Anuren zu klaren.

A chemical study was made of a number of normal dogs' lenses and of parathyroid cataract lenses experimentally produced in dogs. Analytical data on percentage of water, calcium, magnesium, potassium, phosphorus, and silicon thus obtained are presented and compared with other data on the subject. An increase in calcium and a decrease in potassium was found similar to that noted in senile cataract. An extensive review of the literature is presented. From the Department of Physiology, University of Chicago.

It is clear from the few studies which have been done that the parathyroid gland is essential for normal calcium and phosphate homeostasis in reptiles. More studies are needed of different species and groups of reptiles, and of the effect of parathyroid hormone upon bone and kidney of these animals. The explanation for the seeming lack of importance of the parathyroid gland in turtle calcium regulation may lie in the large stores of calcium and phosphate in the bony shells of these animals. Experiments to test this hypothesis are yet to be done. The involvement of the ultimobranchial body in calcium metabolism in reptiles is at present a very tenuous hypothesis. Clearly further studies are necessary to determine the function of this gland, which appears ultrastructurally to be an active secretory organ.

The parathyroid gland of newts in natural hibernation was studied by means of the electron microscope. There were two types of epithelial cells in the parenchyma: one type having numerous filaments and a few cell organoids and other inclusions, and the other type containing few filaments and many cell organoids and other inclusions. Cells of the first type rested on a basement membrane bounding the connective tissue and were termed “basal cells.” Cells of the second type were in a suprabasal position and formed the remainder of the parenchyma. These cells were referred to as “suprabasal cells.” The basal cells might be supporting, rather than secretory, cells. In the suprabasal cells, the nature of the dense bodies, vacuolar bodies, and heterogeneously dense, irregularly shaped masses was discussed. It was suggested that the dense and vacuolar bodies may be lysosomal, the irregularly shaped masses may be lipofuscin pigments in nature, and both might be associated with a control mechanism for secretion.

A case of hyperparathyroidism from carcinoma of the parathyroid gland which recurred locally and metastasised to the lung is described. There was a history of renal lithiasis and peptic ulceration. Improvement followed initial surgical removal but the tumour recurred and death resulted from hyperparathyroidism.

1. 1. Further surgical prevention of parathyroid tetany seems to depend upon the development of the technique of reimplantation of parathyroid tissue at time of operation, especially in patients operated two or more times. 2. 2. Calcium by mouth is of little value in the absence of adequate parathyroid tissue. It is impractical to give it intravenously in chronic tetany. 3. 3. The feeding of dessicated parathyroid gland seems useless. 4. 4. The subcutaneous administration of the parathyroid hormone in dosages as usually given has little, if any, influence on the blood calcium level. Apparently it should be given in much larger dosages. 5. 5. The clinical symptoms seem to be as good a guide to the amount given as the blood calcium level.

Hyperparathyroidism, although a rare disease, is particularly important to the oral surgeon because of the possible oral manifestations. Etiologically, the disease is due to an increase in secretion of the hormone of the parathyroid gland. Two varieties, primary or secondary hyperparathyroidism, may cause the various entities of the disease. The disease occurs mainly between the ages of 40 and 60. Many cases of hyperparathyroidism may go unrecognized until manifestations such as bone involvements or nephrolithiases occur, because the disease can be proved only by laboratory determination. The roentgenographic picture is not distinctive for it may simulate any number of diseases. Histopathologically, the normal bone marrow is replaced by fibrous tissue. Here, again, this alteration may be present in other diseases. Treatment is surgical removal of the tumor of the parathyroid gland or glands. A case report of hyperparathyroidism with skeletal as well as kidney involvement is presented. It was the oral complaints of the patient that made possible the diagnosis of hyperparathyroidism. The close cooperation between the dental and medical professions was necessary for the successful treatment of this patient. The treatment of the oral symptoms of hyperparathyroidism without an understanding of the underlying general disease would be futile.

Raising dietary magnesium from low to high level increased calcium absorption and urinary calcium in parathyroidectomized rats. The net result was increased calcium balance and serum calcium levels in parathyroidectomized rats to approximately normal levels. Supplemental magnesium decreased urinary phosphate in parathyroidectomized rats and phosphate balance and serum phosphate levels were restored to almost control values. Lowering dietary magnesium had the opposite effect on calcium and phosphate absorption and excretion. Although magnesium ions have been reported to have effects on parathyroid function, the results observed in these studies indicate that magnesium ions have a singular effect on calcium and phosphate metabolism irrespective of the presence or absence of the parathyroid gland. Parathyroidectomy had no significant effect on net magnesium absorption. (Endocrinology 85: 1103, 1969)

In recent years the role of the parathyroid gland in relation to certain diseases of the bones has assumed considerable proportions. This subject is of extreme importance to the roentgenologist because of the bony changes observed by the X-ray. In 1904, Askanazy (1) first reported a case of generalized osteitis fibrosa, described by von Recklinghausen (2) in 1891, associated with a parathyroid tumor. In 1907, Erdheim (3) described three cases of osteomalacia in which there was hypertrophy or tumor formation of the parathyroids. This raised a question as to whether the hyperplastic condition of the parathyroid was primary and the skeletal changes secondary or vice versa. Erdheim contended that the enlarged glands were a compensatory change due to the increased drain of calcium metabolism resulting from the bony condition. As late as 1926, Kerl (4) in describing a case of osteomalacia and osteoporosis, believed this possibility. However, most authorities are of the opinion that the enlarged parathyroid is t...

The newt parathyroid gland in natural hibernation and in hyperfunctional conditions induced by the intraperitoneal injection of phosphate was electron-microscopically studied. The average numbers of mitochondria, Golgi apparatus, large homogeneously dense bodies, large heterogeneously dense bodies, vacuolar bodies and lipofuscin-like bodies were counted per 100μ2 of the cytoaplasm from the electron micrographs of the parathyroid glands of the phosphate treated and hibernating (control) newts.The parenchymal cells of the newt parathyroid gland were classified into basal cells and suprabasal cells. Daily administration of phosphate caused no marked changes in the former cells. In the latter under experimental conditions, granular and agranular endoplasmic reticula and small dense granules seemed to be increased in number, while glycogen granules appeared decreased in number when contrasted to those in the control newts. The Golgi apparatus and large homogeneously dense bodies were increased in number reaching a maximum after 7 days of phosphate administration, and lipofuscin-like bodies were gradually increased in number during the experimental stages. On the contrary, vacuolar bodies were first rapidly, then gradually decreased in number. Large heterogeneously dense bodies subdivided into a vesicular type and lysosomal type were slightly decreased during 14 days' administration of phosphate and increased in number after 21 day administration. Under experimental conditions the vesicular type heterogeneously dense bodies were more dominant than the lysosomal type. The numbers of mitochondria were hardly varied as compared with control newts.From the above results it is conceivable that alterations in cell organelles and inclusion bodies indicate hyperfunction of the suprabasal cell caused by phosphate administration. However, mutual correlations of inclusion bodies remain incompletely clarified.

Nach einer kurzen Beschreibung der calciphylaktischen und der sogenannten „direkten“ Gewebsverkalkung wird uber Versuche an Ratten berichtet, die zeigten, das subcutan verabreichtes Indiumchlorid beim nicht calciphylaktisch sensibilisierten, normalen Tier im Sinne eines direkten Verkalkungsstoffes lokal kalkfallend wirkt und auserdem schwere Lebernekrosen mit Ikterus hervorrft. Vorausgehende Nebenschilddrusenexstirpation verhindert die lokale Verkalkung vollkommen, ohne die Lebernekrosen zu beseitigen. Demgegenuber verhindert Vorbehandlung mit Nebenschilddrusenhormon und besonders mit Dihydrotachysterin die Leberschadigung, wahrend es die lokale Gewebsverkalkung verstarkt.

Normal parathyroid glands exhibited two distinct cellular types: one type of cell had a large round nucleus containing fine chromatin granules and a nucleolus; the other type had a round or spindle-shaped nucleus with densely-packed chromatin. The following hormonal preparations were tested and failed to alter parathyroid histology: relaxin extract (R), estradiol cyclopentylpropionate (ECP), combined ECP and R, or various combinations of these hormones with progesterone or cortisone acetate. The pubic joints of the mice underwent the anticipated hormonally-induced changes. Our results are at variance with those of Chase and Shanmugasundaram ('64) who (a) described only one cell type in the mouse parathyroid and (b) reported that relaxin alone or a combination of estrogen and relaxin induced cellular changes suggestive of increased glandular function. The two studies are apparently irreconcilable; however, we did note in about 30% of our mice variable lymphatic aggregates in the thyro-parathyroid complex. Although not actually related to hormonal treatments, it is conceivable that in a small series of animals and without serial sectioning, such lymphatic tissue might be mistaken for altered parathyroid gland.

1. Number, position, size, shape, and vascular bed of the parathyroid glands of Chalcides ocellatus and Scincus scincus are described. The collagenous capsule is pigmented in Chalcides and pigment-free in Scincus. The internal “capillary” network is more developed than the subcapsular. 2. Seasonal changes in the activity of the glands are noticed. From April to October, the glands are active having a compact appearance. In the remaining months, “foraminated”, i.e., partially active glands are found. The glandular tissue can rearrange itself according to the degree of activity, either in the form of rounded lobules or cellular cords. In winter, degeneration takes place and nearly half of the parathyroid tissue is destroyed. In Chalcides, this occurs in the centre of the gland while the rest of the cells show limited activity, because the animal is a non-hibernator. In Scincus, mostly the peripheral part degenerates while the rest of the gland appears foraminated, because the animal is a hibernator. The rebuilding of the glandular tissue presumably takes place by amitosis. Partial destruction of the parathyroid may be caused also during summer by starvation. 3. Large acini are rare in the parathyroid gland of Chalcides but are very frequent in that of Scincus. Their size differs greatly and their condition may indicate the degree of activity of the gland. Their presence might represent a phase of storage of the parathormone, or the colloid of the acini may be inert. 4. Glands of Chalcides individuals subjected for a long time to high temperature are large and show abnormally high concentrations of nuclei. Some of the glands show also degeneration in the centre.

Accessory parathyroid tissue unassociated with the thyroid lobes is present in 5 to 6 per cent. of dogs. For the determination of the presence of accessory parathyroid tissue there are two tests: (1) the anatomical, often entailing serial sections of the neck and upper thoracic structures, and (2) the biological, consisting of the daily use of some calcium salt for two to three weeks. The latter is more easily carried out and more accurate. In the absence of all parathyroid tissue calcium salts will not save the animal's life, while in the presence of active parathyroid tissue calcium will save it. Many factors other than the amount of parathyroid tissue removed influence the onset of tetany, among which are age, pregnancy, lactation, rachitis, the administration of sulphur, and diet. Pregnancy and lactation tetany in dogs resembles in all essentials parathyroid tetany. Our observations are in harmony with those who hold that the thyroid and parathyroid are independent structures as regards their anatomy, physiology, and pathology. The removal of the parathyroids immediately lowers alimentary sugar tolerance, but rarely to the degree of constant glycosuria. In sharp contrast with thyroid substance in myxedema, the feeding of parathyroid substance fresh or dried by mouth is of no value in the parathyroid tetanies of dogs. Calcium salts have a striking palliative effect on parathyroid tetany and preventative action in tiding over otherwise fatal cases, but are in no sense curative. The mode of action is unknown. There is some evidence that calcium salts directly influence the parathyroid gland.

A B S T R A C T Parathyroid function was assessed by calcium infusions (4-8 h) in 16 patients with chronic renal insufficiency being treated by long-term hemodialysis. The concentrations of two immunoreactive species of parathyroid hormone in plasma (iPTH-9, mol wt 9500; iPTH-7, mol wt 7000) were estimated by radioimmunoassays utilizing two relatively specific antisera. Control values of the smaller species, iPTH-7, were uniformly high, whereas values of iPTH-9 were normal in 12 of 19 studies. Response of iPTH-7 to calcium infusions was variable, with significant decreases occurring only five times in 27 infusions. Concentrations of iPTH-9, however, decreased during every calcium infusion. In contrast to these acute responses, five of six patients studied during periods of dialysis against both low (< 6 mg/100 ml) and high (7-8 mg/100 ml) calcium concentrations in the dialyzate showed a decrease in values of iPTH-7 during the period of dialysis against the higher calcium concentration. It is concluded that plasma concentrations of iPTH-9 reflect primarily the moment-tomoment secretory status of the parathyroid glands, while concentrations of iPTH-7 reflect more closely chronic parathyroid functional status. It is further concluded that the failure of iPTH-7 to decrease during induced hypercalcemia should not be equated with autonomy of parathyroid gland function.

AN IMPORTANT advance in knowledge of parathyroid hyperfunction is the fact that lesions of the kidney and parathyroid glands are often closely related. MacCallum drew attention to this relationship in 1905 (1) with his report of a tumor of the parathyroid gland associated with chronic renal disease. Since that time many scattered reports have pointed to some relationship between hyperparathyroidism and kidney disease. Mandl’s pioneer work on the surgical treatment of hyperparathyroidism, and his final proof in1925 of the parathyroid etiology of generalised osteitis fibrosa cystica stimulated much interest in hyperparathyroidism (2). It soon became evident that lesions in the skeletal system were not necessarily the most important, and indeed not even the most frequent pathological change associated with hyperparathyroidism. Due to extensive and careful studies by Albright and his associates (3) in the last few years, the frequency and relatively great importance of renal disease has been recognised.

Proparathyroid hormone (proPTH) and parathyroid hormone (PTH) have been separated from rat gland extracts by a combination of methods including chemical fractionation, gel nitration and ion exchange chromatography. The 2 peptides were shown to be similar to bovine proPTH and PTH, respectively, in their immunoreactivity, molecular weight and size and elution position during chromatography. In radioisotope incorporation studies, they exhibited a precursorproduct relationship comparable to that observed for the bovine prohormone and hormone. After 13 days on a diet containing 0.02% calcium, parathyroid gland weight, size and capacity to synthesize general proteins did not change. In such glands, the content of immunoreactive PTH and synthetic rate for PTH doubled. In contrast, the synthetic rate of proPTH and the half-life of its cellular pool did not change. These data indicate that the parathyroid glands adapted to the low-calcium diet by increasing the efficiency of conversion of proPTH to PTH and suggest...

SummaryThe indirect fluorescent antibody technique revealed local concentrations of parathyroid hormone in intercellular tissue spaces between cords and within acini formed primarily of chief cells in bovine parathyroid glands. In this study, specific immunofluorescence was not seen within parenchymal cells of the parathyroid gland.