Light and Electron Microscopic Studies of Islet Amyloid in Diabetic Cats

Johnson, Kenneth H.; Stevens, J. B.

doi:10.2337/diab.22.2.81

Cited by 43 publications

(14 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, further studies are needed to determine the influence of age on deposition of insular amyloid. Ages of non-diabetic cats with insular amyloid in this study were similar to those reported in diabetic cats with insular amyloid [12]. There was no evidence that breed or sex influenced the incidence of insular amyloid.…”

Section: Discussionsupporting

confidence: 74%

Feline Insular Amyloid: Incidence in Adult Cats with No Clinicopathologic Evidence of Overt Diabetes Mellitus

1981

View full text Add to dashboard Cite

Abstract. Pancreatic tissues from 93 adult domestic cats with no clinicopathologic evidence of overt diabetes mellitus were examined for islet amyloid. Amyloid deposits were found in the pancreatic islets of 44 cats. Approximately one-third of these deposits were not seen with HE, but subsequently were identified with Congo red stain. The proportion of islets with amyloid, the intra-islet location of amyloid, and the amount of amyloid in individual islets also were characterized. In this select population of adult cats, the presence or absence of islet amyloid was not linked significantly (p = > 0.05) to age, breed, sex or primary anatomic diagnosis. Results of this study indicate that: the incidence of islet amyloid in cats is higher than previously recognized; as in man, islet amyloid can occur in cats without concurrent overt diabetes mellitus; and islet amyloid should not be considered pathognomonic for diabetes mellitus.Pancreatic islet amyloid deposits (i.e., insular amyloid) occur in man [2,3,4, 131, non-human primates [7,8, 171, raccoons [ 11, 151, and domestic and wild cats [5, 10, 11, 121. Insular amyloid in man and animals often is associated with maturityonset diabetes mellitus and is rare in juvenile-onset diabetes. A majority of human diabetics over 50 years old have amyloid deposits in their pancreatic islets [I, 4, 13, 201, but insular amyloid also has been identified in a significant number of aged, non-diabetic people [3,4,25]. The amount and frequency of insular amyloid increases with age in both diabetic and non-diabetic people [2,3].A significant relationship exists between the presence of insular amyloid and maturity-onset diabetes, but it is not known whether the amyloid causes diabetes, or arises secondarily to it. Studies of insular amyloid in man indicate that: amyloid deposits are limited to the pancreatic islets [23]; deposition apparently is independent of amyloid in other organs [21]; and systemic (primary or secondary) amyloidosis seems to have no facilitating effect on the formation of insular amyloid [21]. Histochemical, biochemical, and clinicopathologic differences between insular and systemic amyloid imply different and independent mechanisms of formation. Major precursor substances for systemic amyloid are immunoglobulin light chains in primary and myeloma-associated amyloidosis [6], and serum protein AA in secondary 310

show abstract

Section: Discussionsupporting

confidence: 74%

Feline Insular Amyloid: Incidence in Adult Cats with No Clinicopathologic Evidence of Overt Diabetes Mellitus

1981

View full text Add to dashboard Cite

show abstract

“…The occasional periodicity reported may arise from the twisting of a band of fibrils. Insular amyloid in M. nigra is morphologically similar to that in cats [13] and man [6,14,191.…”

Section: Discussionmentioning

confidence: 99%

Insular Amyloidosis in Spontaneously Diabetic Nonhuman Primates

Palotay

Howard

1982

Vet Pathol

View full text Add to dashboard Cite

Abstract. Sections of pancreas from 21 nonhuman primates with diabetes mellitus were examined by light and electron microscopy. All monkeys showed amyloid accumulation in the islets of Langerhans. Amyloid was identified by its dichroism with three different stains: Congo red, changing from red to yellowish-green; standardized toluidine blue, changing from blue to red; and sulfated alcian blue, changing from blue-green to pink. Sulfated alcian blue was a rapid and effective means of detecting amyloid. The characteristic fibrillar structure of amyloid was seen with transmission electron microscopy. Deposition of islet amyloid was independent of the presence or absence of amyloid in other organs. Results indicate that nonhuman primates offer a model for studying the sequential development of insular amyloidotic diabetes mellitus.Causes of the development and progression of diabetes mellitus in man are manifold. There have been continued attempts to link the clinical syndrome to specific islet changes. Although deterioration of the beta cells in the islets of Langerhans is a common feature of juvenile-onset diabetes; there are other factors in other types of diabetes.One lesion in the islets in man has received sporadic attention and continues to be associated with diabetes mellitus. Infiltration of a hyaline material into the islets of Langerhans was described almost 80 years ago [ 171. The hyalin, subsequently identified as amyloid [l, 31, has been seen frequently in the islets of aging people; it is found more often in diabetics than in nondiabetics [2].In our work with spontaneously diabetic nonhuman primates, particularly Mucucu nigru, a consistent phenomenon has been the presence of insular amyloid. The severity of diabetes is linked to the increasing deposition of amyloid in the islets of Langerhans [ 101, and the concurrent deterioration of islet cells. These monkeys are a model for studies on a similar association of amyloid and diabetes in man.In this report, we describe light and electron microscopic findings in normal cells in the pancreatic islets of Langerhans of M. nigru and other nonhuman primates, and document the accumulation of insular amyloid with concurrent deterioration of the islet cells. We also comment on the probable developmental sequence and compare amyloid accumulation in M. nigru with similar phenomena in man and other animals.

show abstract

“…The presence of islet amyloid in nondiabetics in autopsy-based studies may be spurious and based on sampling from biased populations (10,11). Islet amyloid also occurs spontaneously in the diabetic monkey Macaca nigra (12) and in the diabetic domestic cat (13). In humans, amyloid is found more frequently in older diabetic patients (14) and in those with more severe diabetes as shown by requirement for insulin therapy (9,15).…”

mentioning

confidence: 99%

Purification and characterization of a peptide from amyloid-rich pancreases of type 2 diabetic patients.

Cooper

Willis

Clark

et al. 1987

Proc. Natl. Acad. Sci. U.S.A.

1,174

750

View full text Add to dashboard Cite

Deposition of amyloid in pancreatic islets is a common feature in human type 2 diabetic subjects but because of its insolubility and low tissue concentrations, the structure of its monomer has not been determined. We describe a peptide, of calculated molecular mass 3905 Da, that was a major protein component of amyloid-rich pancreatic extracts of three type 2 diabetic patients. After collagenase treatment, an extract containing 20-50% amyloid was solubilized by sonication into 70% formic acid and the peptide was purified by gel filtration followed by reverse-phase high-performance liquid chromatography. We term this peptide diabetes-associated peptide, as it was not detected in extracts of pancreas from any of six normal subjects. Diabetes-associated peptide contains 37 amino acids and is 46% identical to the sequences of rat and human calcitonin gene-related peptide, indicating that these peptides are related in evolution. Sequence identities with conserved residues of the insulin A chain were also seen in a 16-residue segment. On extraction, the islet amyloid is particulate and insoluble like the core particles of Alzheimer disease. Their monomers have similar molecular masses, each having a hydropathic region that can probably form 13-pleated sheets.

show abstract

Light and Electron Microscopic Studies of Islet Amyloid in Diabetic Cats

Cited by 43 publications

References 7 publications

Feline Insular Amyloid: Incidence in Adult Cats with No Clinicopathologic Evidence of Overt Diabetes Mellitus

Feline Insular Amyloid: Incidence in Adult Cats with No Clinicopathologic Evidence of Overt Diabetes Mellitus

Insular Amyloidosis in Spontaneously Diabetic Nonhuman Primates

Purification and characterization of a peptide from amyloid-rich pancreases of type 2 diabetic patients.

Contact Info

Product

Resources

About