No abstract

IGF-I is expressed in somatotrophs, and IGF-I receptors are expressed in most somatotrophs and some corticotrophs in the mouse pituitary gland. Our recent study demonstrated that IGF

No abstract

Reproductive functions decline with the onset of diabetes in female mice. Diabetic mice have smaller uteri with an underdeveloped endometrium, suggesting diminished estrogen-induced growth. We aimed to clarify the changes in the estrous cycle and in insulin-like growth factor 1 (IGF1) expression in the uteri of streptozotocin (STZ)-treated diabetic mice, because IGF1 is one of the main growth factors involved in estrogen-induced uterine growth. ICR female mice were intraperitoneally administered STZ (10 mg/100 g BW), and blood glucose levels were determined. Mice with blood glucose levels > 200 mg/dl were classified as diabetic mice. The onset of diabetes was associated with acyclic estrous cycles. Diabetes was also induced with STZ in ovariectomized mice. Uterine Igf1 mRNA levels were reduced in ovariectomized STZ-treated diabetic mice. Estrogen is known to stimulate Igf1 mRNA expression in the uterus, but estrogen action was abolished in the uteri of STZ-treated diabetic mice. mRNA expressions of estrogen receptor α (ERα) and steroid hormone receptor coactivators (SRC-1/Ncoa1, SRC-2/Ncoa2, SRC-3/Ncoa3 and CBP/p300/Crebbp) were reduced in the uteri of ovariectomized STZ-treated diabetic mice. The present study demonstrates that diabetes induces a decline in female reproductive functions in mice. Igf1 expression in ovariectomized diabetic female mice was decreased, and decreased responsiveness to estrogen in the uteri of diabetic mice is probably associated with a reduction in ERα and steroid receptor coactivator mRNA expression.

No abstract

This is the first report of a patient presenting with rheumatoid factor (RF) positive hypertrophic cranial pachymeningitis (HCP) in association with hypopituitarism and multiple cranial nerve palsies. Our patient developed palsies of the left II and III, bilateral VI and VII, and right IX, X, and XII cranial nerves. A stimulation test showed hypopituitarism due to hypothalamic failure. The patient was seropositive for RF but had no multiple joint pain or deformities. Magnetic resonance imaging (MRI) showed thickened dura of the sellar and parasellar region, hypothalamus, bilateral cavernous sinuses and the tentorium all of which were enhanced by gadolinium (Gd). Treatment with prednisone improved clinical symptoms and MRIfindings concomitant with reduction of RF titer. Although the exact mechanism of HCPhas not been clearly elucidated, the present case suggests an autoimmune mechanism associated with RF. (Internal Medicine 40: 964-967, 2001)

Somatotrophs (GH cells) were classified immunoelectron microscopically into three types mainly on the basis of the size of secretory granules in the mouse pituitary of ICR strain. Type I cells contained large secretory granules. Type II cells contained both large secretory granules and small secretory granules. Type III cells contained small secretory granules. All three types of GH cells were found from the neonatal ages to adult. The relative proportion of three types did not change with age, and no sex differences in the relative proportion of the cell types were detected. Type I cells predominate in all age groups observed. In 60-day-old male mice percentages of each type were as follows: type I 93.7 ± 0.1%, type II 5.4 ± 0.8%, and type III 0.9.0 ± 0.4% (n = 5), and in 60-day-old female mice type I 95.2 ± 0.1%, type II 2.7 ± 0.5%, and type III 2.1 ± 0.9% (n = 5). The maximum diameters of the large secretory granules increased from 7 to 60 days of age. The small secretory granules similarly increased in size in female mice, but those in male mice did not change. In the diabetic female mice of the nonobese diabetic (NOD) strains, GH cells in diabetic mice became smaller, and the number and size of secretory granules decreased, indicating diminished GH secretion. However, the relative proportion of each subtype of GH cells did not differ irrespective of the occurrence of diabetes.

No abstract